10.59987/ads/2012.1.2-10
Aims. The success of maxillary and mandibular tissue supported implant prostheses varies in the literature, and the ideal protocol may be elusive from given the numerous studies. The oral rehabilitation option is an alternative to conventional dentures and should improve function, satisfaction, and retention. The purpose of this review article is to clarify these questions.
Methods. The search of literature reviews English non-anecdotal implant overdentures articles from 1991 to 2011. Results. The results display an aggregate comprehensive list of categorical variables from the literature review. Overall success of maxillary and mandibular implant overdenture was respectively, 86.6% and 95.8%. Conclusion. The literature indicates that the implant overdenture prosthesis provides predictable results – enhanced stability, function and a high-degree of satisfaction compared to conventional removable dentures.
application/pdf
1971-1441
171
1
en
A. De Biase
https://creativecommons.org/licenses/by-nc-nd/4.0
Annali di stomatologia
edentulous
Tissue-supported dental implant prosthesis (overdenture): the search for the ideal protocol. A literature review
Text.Serial.Journal
https://www.annalidistomatologia.eu/ads
3
Review article
2022-08-17
2022-08-17
2012-03-01
2023-12-04
2-10
Ann Stomatol (Roma)
A. De Biase
2012
10.59987/ads/2012.1.2-10
2
1971-1441
1
edentulous
en
10
Tissue-supported dental implant prosthesis (overdenture): the search for the ideal protocol. A literature review
https://www.annalidistomatologia.eu/ads/article/download/171/154
3
                                                                                                          Review article


    Tissue-supported dental implant prosthesis (overdenture):
    the search for the ideal protocol. A literature review




                                                                                                      li
    Domenica Laurito, DDS1                                      tion depend on factors such as age, sex, facial anatomy,
    Luca Lamazza, DMD, DDS1                                     metabolism, oral hygiene, parafunctions, general health,




                                                                                                   na
    Michael J. Spink, MD, DDS2                                  nutritional status, systematic diseases, osteoporosis,
    Alberto De Biase, MD, DDS1                                  drug administration and time of edentulism (2,3).
                                                                Studies to verify the influence of conventional fully-re-
                                                                movable dentures as factor of bone resorption are re-




                                                                                                io
    1
      Sapienza University of Rome, Italy                        plete; patients wearing complete dentures will present
    Department of Oral and Maxillofacial Sciences               with smaller edentulous ridges than edentulous patients
    Division of Oral Surgery                                    with never receiving prosthetics (4). The implant-re-




                                                                            az
    2
      Department of Oral & Maxillofacial Surgery                tained prosthesis is an alternative treatment option in
    Baystate Medical Center, Springfield, MA, USA               edentulous patient’s rehabilitation, providing more re-
                                                                tention, stability, function and esthetics especially in the
                                                                mandible. The use of implants for edentulous patients




                                                                          rn
    Corresponding author:                                       will actually preserve existing bone compared to conven-
    Dott. Alberto De Biase                                      tional dentures (5).
    Department of Oral and Maxillofacial Science                This literature review analyzes the current concepts
    Division of Oral Surgery                                    about indications, implant diameter, length, number,




                                                                te
    Via Caserta 6, 00161 Rome, Italy                            position, prosthetic rehabilitation, early and immediate
    Phone: +39- 06-49976626                                     loading, attachment systems, and implant success rate
    E-mail: alberto.debiase@uniroma1.it                         in mandibular and maxillary overdentures.
                                                        In
                                                                Methods
    Summary
                                            ni
                                                                This study searches for the subject’s validity and efficacy
    Aims. The success of maxillary and mandibular tis-
                                                                of available information from English published literature
    sue supported implant prostheses varies in the lit-
                                                                within PUBMED from 1991-2011. The search identifies
    erature, and the ideal protocol may be elusive from
                                    io


                                                                the key words: overdenture, dental implant, osseointe-
    given the numerous studies. The oral rehabilitation
                                                                gration, edentulous. A manual search of aforementioned
    option is an alternative to conventional dentures and
                                                                articles’ reference lists expands this subject’s informa-
    should improve function, satisfaction, and retention.
                            iz



                                                                tion.
    The purpose of this review article is to clarify these
                                                                This composite search narrows if the articles meet the
    questions. Methods. The search of literature re-
    views English non-anecdotal implant overdentures            following criteria: 1) type of study (randomized controlled
              Ed




    articles from 1991 to 2011. Results. The results dis-       trial, review of the literature with or without meta-anal-
    play an aggregate comprehensive list of categorical         ysis, longitudinal experimental clinical studies, longitu-
    variables from the literature review. Overall success       dinal prospective studies, and longitudinal retrospective
    of maxillary and mandibular implant overdenture             studies); 2) period of publication (1991 to 2011); and 3)
    was respectively, 86.6% and 95.8%. Conclusion.              type of patient (maxillary and/or mandibular fully edentu-
    The literature indicates that the implant overdenture       lism for tooth decay and periodontal disease).
 IC




    prosthesis provides predictable results – enhanced          The exclusion criteria is: 1) type of study (case reports,
    stability, function and a high-degree of satisfaction       case sequence, clinical innovation report, description of
    compared to conventional removable dentures.                the surgery complications, advice from experts); and 2)
                                                                type of patient (oral cancer patients).
C




    Key words: overdenture, dental implant, osseointe-
    gration, edentulous.
                                                                Results
©




                                                                The data explores mandibular and maxillary overden-
    Introduction                                                ture’s indications, implant diameter, length, number and
                                                                position, prosthetic rehabilitation, immediate and early
    Bone resorption will occur in an edentulous alveolus. The   loading, attachment system and implant success rates.
    ubiquitous phenomenon is a progressive and irrevers-        The following categorical variables display an aggregate
    ible (1). The amount and rate of alveolar bone resorp-      comprehensive list from the literature review:


    2                                                                                   Annali di Stomatologia 2012; III (1): 2-10
    Tissue-supported dental implant prosthesis (overdenture): the search for the ideal protocol. A literature review



    Indications                                                             plants necessary to support a maxillary overdenture
                                                                            (26,27). A minimum of four well-spaced implants is often
    The following patients would benefit from a tissue-sup-                 recommended for an implant-supported and retained-
    ported implant overdenture:                                             overdenture. The increased minimum of implants com-
    •   advanced atrophy eliminating the potential for total                pared to the mandible is due to the softer bone and type




                                                                                                                     li
        implant-supported prosthesis;                                       of distribution of occlusal forces in the maxilla. However,
    •   augmentation procedures are excluded for any                        the use of only two maxillary implants may not compro-




                                                                                                                  na
        reasons;                                                            mise implant survival or patient satisfaction. The most
    •   possess natural teeth in the opposing arch, fixed or                posterior implant should be inserted as far distally as
        removable prostheses supported by implants and                      possible to reduce the extension of cantilever (28).
        teeth;
    •   elderly patients who, having had complete




                                                                                                               io
        dentures for many years, lose their motor skills and                Implant position
        no longer feel able to wear complete dentures (6);                  Although not standard, studies recommend four intrafo-
    •   compromised conventional denture retention, e.g.                    raminal implants for cases of advanced atrophy or thin




                                                                                        az
        resection defects, xerostomia or parafunction.                      mandibular ridges. For these instances, implants should
                                                                            be equidistant apart, or as an alternative one can mount
                                                                            a cantilever-fixed prosthesis; in fact, the bar segments
    Implant diameter and length                                             may become rather short, and short female bar retainers




                                                                                      rn
    The implant diameter depends on the alveolar width,                     are subject to frequent loosening or loss. The length of
    whereas the available bone height determines the im-                    the bar segments can range from 15 to 25 mm. The total
    plant length (7). The implant length should be ≥ 10 mm,                 number of intraforaminal implants distribution should be




                                                                           te
    and a minimum diameter of 3.3 - 4.1mm for the man-                      related to the shape of the ridge. If a large or V-shaped
    dibular anterior while 4.1mm for the maxilla (8). The lit-              anterior ridges exists, three to four implants will provide
    erature provides evidence of an increased failure rate                  for a more favorable design of the bar and the prosthe-
    for short implants – 7 and 10 mm (9). Narrow diameter
                                                                In          sis. In presence of U-shaped mandibular jaw, two ante-
    implants (2.5 to 3 mm) can be successfully used to treat                rior implants could provide for a bar of adequate length.
    narrow bone ridges although more long-term studies are                  A U-shaped mandible with large curvature allow for an
    needed to compare narrow and conventional diameter                      adequate placement of four implants and a connecting
    implant outcomes (10,11). In both the maxilla and the                   bar. Alignment of the implants in a rather straight line is
                                                   ni

    mandible, wide-diameter implants may provide addition-                  not favorable for fixed prostheses.
    al support for removable partial dentures. However, the                 The best anchorage design for the maxilla is four equi-
    use of wide-diameter implants for anchorage of remov-                   distance implant, but six implants for compromised bone
                                           io


    able partial dentures still requires critical evaluation to             (29). Positioning the implants in anterior maxilla, me-
    assess whether wide-diameter implants affect the supra-                 sial to the first premolars enhances the stability of the
    structure design. Using standard-diameter implants, the                 overdenture. For a design without palatal coverage, the
                                 iz



    suprastructure may frequently be better designed and                    consensus favors a minimum of four implants (30-34).
    more comfortable for the patient (12).                                  In order to avoid dramatic changes in prosthetic design,
                                                                            one investigator recommends six implants (35). Despite
                 Ed




                                                                            this recommendation, others clinicians implant progno-
    Implant number                                                          sis were not compromised with the presence of compro-
    The two-implant overdenture therapy is a very reliable                  mised quality and quantity of bone, off-ridge relations, or
    therapy for patients with an edentulous mandible (13). A                high applied forces, and palatal coverage (36).
    several authors hypothesizes that it is appropriate to use
    two implants with an interconnector parallel to the hinge
 IC




    axis and a resilient overdenture on an ovoid or round bar               Prosthetic rehabilitation
    (14-16). The bar’s purpose is to enhance free rotation                  There is a direct correlation between the number of im-
    during dorsal loading with twist-free load transmission                 plants and prosthetic design. The number of implants
C




    to the implants (17). Comparative prospective studies                   influences type and design of prosthesis whereas the
    validate the benefit of two or four implants in the edentu-             prosthetic design determines the number of implants.
    lous mandible (18-22). Survival rates in the two-implants               Additionally, the distribution of the implants over the arch
    overdenture groups compared with four-implant over-                     is related to size, curvature and shape of the ridges.
©




    denture groups appear to be equivalent for patient sat-                 A rigid bar connecting multiple implants and cast metal
    isfaction (23). One ten-year trial displays no significant              framework reinforce denture base to ensures stabil-
    clinical and radiographic differences in patients treated               ity and stiffness. Several investigators demonstrate, in
    with two or four implants overdenture (24). However, a                  vitro and in vivo, that bars provide more retention than
    mandibular overdenture with two implants and a bar has                  solitary anchors when subjected to both vertical and
    fewer complications (25).                                               oblique forces (37-39). If a bar connector interferes with
    There are no specific guidelines for the number of im-                  space for tongue, then ball anchors are best. Anterior

    Annali di Stomatologia 2012; III (1): 2-10                                                                                        3
    D. Laurito et al.



    positioned mandibular implants may result in a shorter         single attachments to bars, there are data shows that
    prosthetic bar length; however, it may be adequate in          bars are more retentive while the magnetic attachments
    presence of three or four intraforaminal implants. As          are less retentive (54,55). The data hints that bars-clip
    an alternative, four intraforaminal implants can support       assembles appear to be more retentive for the break
    a fixed-cantilever mandibular prostheses. The attach-          load when subject to both vertical and oblique forces.




                                                                                                          li
    ment system seems not to interfere with prognosis of           These attachments also provide the fastest release peri-
    two implants mandibular overdenture writes a ten-year          ods. Their selection is ideal when there is a requirement




                                                                                                       na
    randomized clinical trial of splinted and unsplinted oral      for high degree of retention, e.g. cases with extremely
    implants retaining mandibular overdentures (40).               resorbed ridges without tissue undercuts. The retentive
    An in vitro edentulous maxilla study utilizing four im-        forces of most attachment systems are in the range of
    plants demonstrates improved retention of bar over-            about 20N (56). Forces of 20N are probably sufficient
                                                                   for overdentures in the edentulous mandibles is a be-




                                                                                                    io
    dentures with distal ERA® attachments rather than a
    cantilevered bar with Hader clips (41). The distribution       lievable documented assumption. Published research
    of supporting implants may influence their survival due        agrees on the fact that the least retentive attachments
    to forces acting on the prosthesis in the maxilla (42). The    are the magnets. This clinical approach lost popularity,




                                                                              az
    rationale of fabricating a single bar supported by two or      particularly when clinicians discovered that this attach-
    more implants, allowing pure rotational movement of the        ment system corrode rapidly in saliva. Their attractive
    prosthesis to equitably share support with the mucosa, is      force is weaker (mean of 2N or less) than ball or bar at-
    not practical because of the difficulty of optimal position-   tachments (57,58). Since magnets will displace with ex-




                                                                            rn
    ing of the implants. This type of hinging design does not      cessive force, some investigators suggest their use with
    improve implant survival (43). A broadly distributed im-       bruxers (55). However, newly designed rare-earth alloys
    plant-supported design, spanning the anterior-premolar         seems to provide more magnetic force per unit size, and




                                                                   te
    region and tuberosities, shows the most favorable stress       new laser-welding techniques contribute to the construc-
    transfer to bone compared to a concentrated array of im-       tion of strong and durable containers for protecting the
    plants in the anterior region supporting a cantilever (44).    magnets from salivary corrosion (59).
    Bars with distal cantilevers tend to increase the loads
                                                           In      Literature data about peri-implantitis shows no signifi-
    on the terminal implants by more than three-times in the       cant differences between different attachment systems.
    maxilla (45). If parallel alignment of the implant axes is     Cehereli in his systematic review writes that no differenc-
    possible, a ball anchor-supporting maxillary overdenture       es exist regarding bone loss around mandibular implant
    can be a long-term provisional restoration. However, the       retained/supported overdentures with different types of
                                              ni

    use of two ball anchors results in a hinging movement of       attachment systems (60). However, investigators specu-
    the denture that may cause discomfort.                         late for the reason this loss due to different loading pat-
    Magnets display the least retentive of all attachment sys-     terns or bone conditions.
                                     io


    tems, but may be appropriate for patients with bruxism         Evaluation of soft tissue reactions to different attachment
    or dexterity problems (46). Unsplinted anchorage sys-          systems exists. The maxilla is more prone to hyperplasia
    tems may require less space within the prosthesis, may         and mucositis around implants. The excellent denture
                             iz



    be easier to clean and more economical, as well as less        retention avoiding a sufficient cleaning mechanism of
    technique sensitive (47). In the vertical axis, a minimum      saliva may be responsible for these adverse reactions.
    distance of 13-14 mm from the implant platform to the in-      Plaque accumulation is significantly higher for magnets
                Ed




    cisal edges is necessary with a bar design, allowing 4.0       than for ball attachments whereas there is no significant
    mm for the bar and 1.0 mm below the bar for hygiene,           differences between bar and ball design, or bar and
    as well as space for the clip and acrylic/tooth housing        magnets.
    (48). However, the use of attaching mechanisms such            Another study finds less bleeding with ball attachments,
    as a bar-clip (Hader, Attachments Intl., Inc., San Mateo,      when compared to a single bar attached to two implants
                                                                   or triple bar to four implants. Ball attachments are, in fact,
 IC




    Ca, USA) requires a minimum distance of 10-12 mm be-
    tween implants, otherwise a milled bar with a frictional fit   easier to clean than bars (18). Two studies conclude that
    superstructure is needed (49). Solitary anchors require        implant-supported overdentures may maintain health
    only 10 to 11 mm of vertical space above the implant           and stability independent of the retentive device used
C




    platform to incisal edges and also allow for more flex-        for anchorage (61). It is likely that peri-implant health for
    ibility in positioning, given anatomic limitations (50,51).    overdentures is not influenced by the number of implants
                                                                   (62). However, by increasing the number of implants, the
                                                                   potential for single axis fulcrum movement decreases
©




    Attachment systems                                             and so do the retention-release episodes during func-
    Implant overdentures use one of three attachment sys-          tion. Different stress distribution is a result of the type of
    tems: 1) resilient attachments on freestanding implant         attachment system.
    abutments; 2) resilient attachments to join the denture to     Photoelastic studies demonstrate the ideal stress dis-
    a rigid bar assembly that interconnects osseointegrated        tribution concerning length, geometry, and diameter of
    implants (52,53); 3) or magnets system (54).                   implants, although some limitations exist with this type
    The comparison between the retentive properties of             of study. The best design would compare different stress

    4                                                                                       Annali di Stomatologia 2012; III (1): 2-10
    Tissue-supported dental implant prosthesis (overdenture): the search for the ideal protocol. A literature review



    patterns from different retentive mechanisms from im-                   (73). Insufficient data exist to support early and immedi-
    plants of the same length, geometry, and diameter.                      ate loading for the maxillary overdentures (74-76).
    The ball (O-ring) attachments transfers less stress
    than bar and clips when applying vertical forces on a
    two implant supported mandibular overdenture. In vitro                  Early-loading of the implant-supported




                                                                                                                     li
    and in vivo studies compare the stresses on the bone                    mandible overdentures
    surrounding two implants with either a bar- clip or ball                The literature review draws the following conclusions




                                                                                                                  na
    attachments for overdentures (63,64). Their discovery                   about mandibular overdentures: success or survival of
    is a greater stress exist on the peri-implant bone with                 implant is not in jeopardy with early-loading, but few
    a bar- clip attachment. Photoelastic studies reproduce                  studies exist; both splinted and unsplinted implants with-
    the findings (18). In vitro and in vivo studies verify the              stand the biomechanical demands of early-loading (77);




                                                                                                               io
    higher stability with ball attachments and how load is                  success is a function of bone quality and primary sta-
    evenly dispersed onto the residual ridge of both site of                bility; and, survival and success rates for early-loaded
    the dental arch (63,65,66). This finding may result from                implants are comparable to conventionally-loading pro-
    an allowed flexure of the mandible.                                     tocols.




                                                                                        az
    Advocates of the bar-clip attachment design speculates                  No deleterious effects up to twenty-four months exist
    that the denture can freely rotate around the bar, thus                 with immediate or early-loading, although there appears
    compensating for the resilience of the supporting mucosa                to be more support for early over immediate-loading. In
    and reducing the torsion forces to the implants (57). How-              order to provide the most astute evidence to support the




                                                                                      rn
    ever, measured force transmission onto implants support-                most appropriate time to load implants, study designs
    ing overdentures with piezoelectric transducers show the                should be randomized -controlled clinical and a follow-
    maximum forces measured in the vertical direction are                   up period greater than twenty-four months (78).




                                                                           te
    higher with single telescopes than with bars and clips.                   One review exists that compares three different tim-
    And, rigid bars contribute to load sharing between the im-              ing of loads: early progressive loading, early functional
    plants (67). Contrary to the rationale and theory of free               loading, and immediate-early functional loading. In the
    rotation, recent data suggests that even if a bar that al-
                                                                In          early progressive loading, the patient does not wear their
    lows rotational movement, a higher load will transfer to the            dentures for one to two weeks, or else worn, but com-
    implants because of the difficulty to obtain optimum im-                pletely relieved from the healing abutment. Typically, the
    plant position, which would allow a pure rotational move-               practitioner relines the prosthesis at three to four months
    ment (43). Therefore, a design should be an equilibrium                 when the definitive prosthesis connects to attachments
                                                   ni

    between load of implant and denture bearing area.                       (ball or bar assembly). In early functional loading, there
    Nevertheless, the literature is in disagreement – longitu-              is a hiatus after surgery for two weeks prior to relining the
    dinal prospective studies conclude that is no differences               dentures. Then, the protocol connects the retentive com-
                                           io


    in implant survival rate, peri-implantitis, or marginal bone            ponents (ball attachments) within three weeks. Finally,
    loss in the two different anchorage systems on two im-                  for immediate-early functional loading protocols, the
    plants retaining an overdenture (68,69). Furthermore,                   protocol requires to connect the retentive attachments
                                 iz



    another study concludes that the direction of occlusal                  within five days. The authors stated that the loading dif-
    forces is more influential than the connection of implants              ferences between the three groups are rather tenuous,
    and that the difference in stress concentration between                 since the time and method of loading overlaps (79).
                 Ed




    models with and without a bar is small (70). In an in vivo              Studies also suggest that implants splinted together with
    study using a two-implant supported model, investiga-                   a bar within a short period of time to prevents axial ro-
    tors observe that the anchorage system may has less of                  tation and implant micromotion (80,81). However, other
    an influence than other parameters, such as superstruc-                 studies describe the use of fewer implants (minimum of
    ture fit and occlusion, and may also determine loading of               two) that were left exposed and unsplinted after an initial
 IC




    implants (71).                                                          healing phase of two to three weeks. Therefore, one can
    There is no significant difference in stress distribution               contend that splinting implants in the anterior mandible
    between stud attachments and resilient bar-clip designs                 is not a definite requirement for osseointegration with
    if the prostheses are well-designed prosthesis and both                 these protocols (82). In addition splinted or unsplinted
C




    under ideal conditions. However, rigid designs and can-                 design seems to not influence implant survival rate and
    tilever bars are more will increase the force transmitted               periimplant outcome (83).
    to the implant fixtures.
©




                                                                            Implant success rate
    Immediate-loading of Implant-supported overdentures                     Studies carried out in the last years to assess the ben-
    The literature review draws the following conclusions                   efits of implant-supported overdenture with at least five
    about mandibular overdentures: immediate loading of                     years of follow-up show that survival of implants support-
    mandibular overdentures does not jeopardizes the sur-                   ing overdentures in the medium and long term is very
    vival rate when designed with four implants (72); and,                  high. Table-1 displays a report of several studies.
    success is a function of bone quality and primary stability             The analysis of the available literature shows that im-

    Annali di Stomatologia 2012; III (1): 2-10                                                                                         5
    D. Laurito et al.



    plant-supported prosthetic restoration offers excellent          tures (89). Many options are available for retention of
    rates of success in mandible and maxilla if practitioners        the prosthesis, including magnets, clips, bars and ball.
    follow common protocols (84,85).                                 The resultant implant-supported overdenture has good
    In many cases, the edentulous maxilla rehabilitation re-         stability and retention. Most authors agree on a require-
    quires more elective procedures rather than in mandible,         ment of a passive fit between the prosthesis framework




                                                                                                             li
    because a different degree of atrophy, prospective loca-         and osseointegrated dental implants.
    tion of the implants and inclination of the implant axis,        In 1983, Branemark defined passive fit, and he proposed




                                                                                                          na
    tissue volume dimensions, facial morphology, esthetics,          this should be at the level of 10 μm to enable bone matu-
    function and phonetics exists.                                   ration and remodeling in response to occlusal loads (90).
    There is a high failure rate for maxillary overdentures,         In 1991, Jemt defined passive fit as the level that did not
    i.e. over 20% (86). A critical analysis of the treatment         cause any long-term clinical complications (91). And he




                                                                                                       io
    outcomes reveals that overdenture is often a treatment           suggests misfits of smaller than 150 μm as acceptable.
    option in compromised patients, where fixed prostheses           Although these preceding values are a reference, they
    fails (71). Otherwise, there is high survival rate of implant    are of empirical origin.
    when the overdenture is well planned (43).                       The survival rates for the mandible are clearly better than




                                                                                    az
                                                                     the maxilla – a function of the mandible’s denser bone
                                                                     and shorter prosthetic lever arms that promote resist a
    Discussion                                                       hinging movement. Treatment considerations for implant
                                                                     overdentures on the maxilla appear to be different than




                                                                                  rn
    A variety of treatment options exist to rehabilitate fully       for those on the mandible. Atrophy of edentulous jaws
    edentulous patients: two to up to six or more implants,          may limit implant placement on the maxilla, whereas in
    removable implant-retained overdenture, fixed implant-           the mandible, the reduction of residual ridge often leaves




                                                                     te
    supported bridge, etc (87). The basis for individual treat-      a significant depth and width of basal bone anteriorly to
    ment options is a factor of:                                     accommodate implants. The maxilla’s bone trabecular
    •   Patient-related factors: patient’s expectations,             bone is less dense and not as capable of stabilizing and
        subjective     aesthetics,     phonetics,
                                                            In
                                                      financial      supporting implants. Anatomic limitations and bony mor-
        commitment, comfort, compliance, and maintenance             phology may compromise implant number, length, and
        of oral hygiene;                                             inclination. The maxillary overdenture reports a greater
    •   Absence of signs and symptoms: persistent pain,              burden of maintenance care and higher failure rates in
        infection, neuropathy, invasion of the mandibular            contrast to the mandible.
                                                ni

        channel or chronic sinusitis;                                In longitudinal studies, the average annual alveolar ridge
    •   Extraoral factors: patient’s co-morbidities, objective       height resportion is approximately 0.4 mm in the eden-
        aesthetics, facial profile, type of smile line, and lip      tulous anterior mandible. The anterior mandibular bone
                                      io


        support;                                                     under an implant overdenture may resorb as little as 0.5
    •   Intraoral factors: local anatomy (fibromas, bands,           mm over a five-year period, and long-term resorption
        muscle attachments, floor of mouth frenula),                 may remain at 0.1 mm annually (57,58). One study ob-
                              iz



        maxillo-mandibular relationship, presence or                 serves that the functioning or loading of implants creates
        absence of buccal fold, keratinized attached mucosa          positive bone remodeling in the anterior mandible (89).
        and jaw bone quality and quantity, edentulous                This effect appears to be independent of the attachment
                Ed




        crestal morphology (shape, height and width) and             system (18).
        prosthesis crown position in the sagittal plane.             Overdenture wearers show a masticatory performance
                                                                     and chewing cycles similar to those with natural teeth.
    The implant-retained overdenture proves to be predict-           They also document an increase of comfort and satis-
    able and effective management for edentulous patients.
 IC




    Biological (e.g. non-osseointegration, peri-implantitis,
                                                                          Study            Implant success rate            Follow up
    mucositis with or without inflammatory hyperplasia) and
    biomechanical complications (e.g. bar fracture, fracture                              Maxilla         Mandible
    or detachment of the clip anchorage fracture of the pros-
C




    thesis or its parts, etc.) can occur, but the literature still    Naert (33)           88,6%                            4 years
    reports years of success (88).
                                                                      Bergendal (43)       75.4%             100%           7 years
    The implant-supported overdenture’s biggest advantage
    is a better distribution of occlusal forces between implant       Naert   (40)
                                                                                                             100%           10years
©




    and bone. This results in a reduction of alveolar ridge           Jemt (91)            72.4%            94.5%           5-years
    resorption; longitudinal clinical studies report a loss of        Kiener   (30)
                                                                                           95.5%                            8 years
    bone height adjacent to implants of approximately 1.2
    mm at the end of the first-year and 0.2 mm annually.              Visser (21)                           99.9%           5 years
    This resorption is lower compared with a reduction of
    4 mm at the end of the first year and 0.4 mm annually            Table 1. Clinical studies showing implant success rate in maxil-
    after tooth extraction when fitting with conventional den-       lary and mandibular overdentures.


    6                                                                                          Annali di Stomatologia 2012; III (1): 2-10
    Tissue-supported dental implant prosthesis (overdenture): the search for the ideal protocol. A literature review



    faction in patients with their overdentures compared                        implants for mandibular denture retention. J Calif Dent As-
    to patients wearing conventional dentures. A study ad-                      soc. 2008 Apr;36(4):283-286.
    dressing two mandibular implant-supported overden-                      12. Krennmair G, Waldenberger O. Clinical analysis of wide-
    ture concludes that this significantly improves measure                     diameter frialit-2 implants. Int J Oral Maxillofac Implants.
    of oral function. After ten years of function, values for                   2004 Sep-Oct;19(5):710-715.




                                                                                                                     li
    maximum bite force and masticatory performance re-                      13. Vercruyssen M, Marcelis K, Coucke W, Naert I, Quirynen
    main unaltered. Thus, the improved oral function lasts                      M. Long-term, retrospective evaluation (implant and




                                                                                                                  na
    for a long period of time with high levels of satisfaction                  patient-centred outcome) of the two-implants-supported
    regarding various aspects of patients denture function. If                  overdenture in the mandible. Part 1: survival rate. Clin Oral
    similar oral functions problems exist, implant-supported                    Implants Res 2010 Apr 1;21(4):357-365.
    patients report a greater level of satisfaction (92,93).                14. Misch CE. Contemporary implant dentistry. 2nd ed. St.




                                                                                                               io
    The literature indicates that the implant overdenture                       Louis (MO): Mosby; 1999. p. 179.
    prosthesis provides predictable results – enhanced sta-                 15. Wright PS, Watson RM. Effect of prefabricated bar design
    bility, function and a high-degree of satisfaction com-                     with implant- stabilized prostheses on ridge resorption: a
                                                                                clinical report. Int J Oral Maxillofac Implants 1998; 13:77-




                                                                                        az
    pared to conventional removable dentures. This is as a
    result of positive outcomes of long-term clinical studies,                  81.
    specifically using a conventional loading protocol. Fur-                16. Naert I, Gizani S, Vuylsteke M, Van Steenberghe D. A
                                                                                randomised clinical trial on the influence of splinted and
    ther studies focusing on immediate and early loading in
                                                                                unsplinted oral implants in the mandibular overdenture




                                                                                      rn
    maxillary overdenture are necessary.
                                                                                therapy. A 3-year report. Clin Oral Investig 1997;1:81-88.
                                                                            17. Sadowsky SJ. Mandibular implant-retained overdentures:
                                                                                a literature review. J Prosthet Dent 2001 Nov; 86(5):468-




                                                                           te
    References                                                                  473.
                                                                            18. Batenburg RHK., Raghoebar GM, Van Oort, RP, Heijden-
     1. Carlsson GE. Clinical morbidity and sequelae of treatment               rijk K, Boering G. Mandibular overdentures supported by
                                                                                two or four endosteal implants. A prospective, comparative
        with complete dentures. J Prosthet Dent 1998;79:17-23.
                                                                In
     2. Kreisler M, Behneke N, Behneke A, D’Hoedt B. Residual                   study. Int J Oral Maxillofac Surgery 1998b; 27: 435-439.
        ridge resorption in the edentulous maxila in patients with          19. Wismeijer D, Van Waas MAJ, Mulder J, Vermeeren JI, Kalk
        implant-supported mandibular overdentures: an 8-years                   W. Clinical and radiographical results of patients treated
        retrospective study. Int J Prosthodont 2003;16:265-300.                 with three treatment modalities for overdentures on im-
                                                   ni
     3. Carlsson GE. Responses of jawbone to pressure. Ger-                     plants of ITI dental implant system. A randomized con-
        odontology 2004;21:65-70.                                               trolled clinical trial. Clin Oral Implants Res 1999;10: 297-
     4. Campbell RL. A comparative study of the resorption of the               306.
                                           io


        alveolar ridges in denture-wearers and non-denture-wear-            20. Mau J, Behneke A, Behneke N, Fritzemeier CU, Gomez-
        ers. J Am Dent Assoc 1960;60:143-153.                                   Roman G, D’Hoedt B, Spiekermann H, Strunz V , Yong M.
     5. Salinas TJ. Implant Prostthodontics. In: Miloro M, Ghali                Randomized multicenter comparison of 2 IMZ and 4 TPS
                                 iz



        GE, Larsen PE, Waite PD. Peterson’s Principles of Oral                  screw implants supporting bar-retained overdentures in
        And Maxillofacial Surgery. London: BC Decker Inc Hamil-                 425 edentulous mandibles. Int J Oral Maxillofac Implants
        ton; 2004 p. 263.                                                       2003; 18: 835-847.
                 Ed




     6. Mericske-Stern RD, Taylor TD, Belser U. Management of               21. Visser A, Raghoebar GM, Meijer HJA, Batenburg RHK,
        the edentulous patient. Clin Oral Impl Res 2000;11 (Sup-                Vissink A. Mandibular overdentures supported by two or
        pl.): 108-125.                                                          four endosseous implants. A 5-year prospective study. Clin
     7. Weingart D, Ten Bruggenkate CM. Treatment of fully eden-                Oral Implants Res 2005; 16:19-25.
        tulous patients with ITI implants. Clin Oral Impl Res 2000;         22. Stoker GT, Wismeijer D, Van Waas MAJ. An eight-year fol-
        11 (Suppl.): 69-82.                                                     low-up to a randomized clinical trial of aftercare and cost-
 IC




     8. Romeo E, Chiapasco M, Lazza A, Casentini P, Ghisolfi M,                 analysis with three types of mandibular implant-retained
        Iorio M, Vogel G. Implant-retained mandibular overden-                  overdentures. J Dent Res 2007; 86:276-280.
        tures with ITI implants. Clin Oral Implants Res 2002 Oct;           23. Timmerman R, Stoker GT, Wismeijer D, Oosterveld P, Ver-
        13(5):495-501.                                                          meeren JIJF, Van Waas MAJ. An eight-year follow-up to
C




     9. Sadowsky SJ. Treatment considerations for maxillary im-                 a randomized clinical trial of participant satisfaction with
        plant overdentures: A systematic review. J Prosthet Dent                three types of mandibular implant-retained overdentures. J
        2007 Jun; 97(6):340-348.                                                Dent Res 2004; 83: 630-633.
    10. Anitua E, Errazquin JM, de Pedro J, Barrio P, Begoña L,             24. Meijer HJ, Raghoebar GM, Batenburg RH, Visser A, Vis-
©




        Orive G. Clinical evaluation of Tiny® 2.5- and 3.0-mm                   sink A. Mandibular overdentures supported by two or four
        narrow-diameter implants as definitive implants in different            endosseous implants: a 10-year clinical trial. Clin Oral Im-
        clinical situations: a retrospective cohort study. Eur J Oral           plants Res. 2009 Jul;20(7):722-728.
        Implantol. 2010 Winter;3(4):315-322.                                25. Klemetti E. Is there a certain number of implants needed to
    11. LaBarre EE, Ahlstrom RH, Noble WH. Narrow diameter                      retain an overdenture? J Oral Rehabil. 2008 Jan;35 Suppl




    Annali di Stomatologia 2012; III (1): 2-10                                                                                             7
    D. Laurito et al.



        1:80-84.                                                               designs. J Prosthet Dent 2001;86:603-607.
    26. Ekfeldt A, Christiansson U, Eriksson T, Linden U, Lundqvist        42. Heckmann SM, Winter W, Meyer M, Weber HP, Wichmann
        S, Rundcrantz T, Johansson LA, Nilner K, Billström C.                  MG. Overdenture attachment selection and the loading of
        A retrospective analysis of factors associated with mul-               implant and denture-bearing area. Part 2: A methodologi-
        tiple implant failures in maxillae. Clin Oral Implants Res             cal study using five types of attachments. Clin Oral Im-




                                                                                                                   li
        2001;12:462-467.                                                       plants Res 2001;12:640-647.
    27. Kronstrom M, Widbom C, Soderfeldt B. Patient evaluation            43. Bergendal T, Engquist B. Implant-supported overdentures:




                                                                                                                na
        after treatment with maxillary implant-supported overden-              a longitudinal prospective study. Int J Oral Maxillofac Im-
        tures. Clin Implant Dent Relat Res 2006;8:39-43.                       plants 1998;13:253-262.
    28. Weingart D, Ten Bruggenkate CM. Treatment of fully eden-           44. Benzing UR, Gall H, Weber H. Biomechanical aspects of
        tulous patients with ITI implants. Clin Oral Impl Res 2000;            two different implant-prosthetic concepts for edentulous
                                                                               maxillae. Int J Oral Maxillofac Implants 1995;10:188-198.




                                                                                                             io
        11 (Suppl.): 69-82.
    29. Slot W, Raghoebar GM, Vissink A, Huddleston Slater JJ,             45. Kramer A, Weber H, Benzing U. Implant and prosthetic
        Meijer HJA. A systematic review of implant-supported max-              treatment of the edentulous maxilla using a bar-supported
        illary overdentures after a mean observation period of at              prosthesis. Int Oral Maxillofac Implants 1992;7:251-255.




                                                                                      az
        least 1 year. J Clin Periodontol 2010; 37: 98-110.                 46. Trakas T, Michalakis K, Kang K, Hirayama H. Attachment
    30. Kiener P, Oetterli M, Mericske E, Mericske-Stern R. Effec-             systems for implant retained overdentures: a literature re-
        tiveness of maxillary overdentures supported by implants:              view. Implant Dent 2006;15:24-34.
        maintenance and prosthetic complications. Int J Prostho-           47. Watson CJ, Tinsley D, Sharma S. Implant complications




                                                                                    rn
        dont 2001;14:133-140.                                                  and failures: the complete overdenture. Dent Update
    31. Lewis S, Sharma A, Nishimura R. Treatment of edentulous                2001;28:234-8,240.
        maxillae with osseointegrated implants. J Prosthet Dent            48. Phillips K, Wong KM. Space requirements for implant




                                                                           te
        1992;68:503-508.                                                       bar-and-clip overdentures. Compend Contin Educ Dent
    32. Mericske-Stern R. Treatment outcomes with implant-sup-                 2001;22:516- 8, 520, 522.
        ported overdentures: clinical considerations. J Prosthet           49. Zitzmann NU, Marinello CP. Implant-supported removable
        Dent 1998;79:66-73.                                                    overdentures in the edentulous maxilla: clinical and techni-
                                                                  In           cal aspects. Int J Prosthodont 1999;12:385-390.
    33. Naert I, Gizani S, van Steenberghe D. Rigidly splinted im-
        plants in the resorbed maxilla to retain a hinging overden-        50. Phillips K, Wong KM. Vertical space requirement for the
        ture: a series of clinical reports for up to 4 years. J Prosthet       fixed-detachable, implant-supported prosthesis. Compend
        Dent 1998;79:156-164.                                                  Contin Educ Dent 2002;23:750-2, 754, 756.
                                                    ni
    34. Smedberg JI, Lothigius E, Bodin I, Frykholm A, Nilner K. A         51. Narhi TO, Hevinga M, Voorsmit RA, Kalk W. Maxillary
        clinical and radiographic two-year follow-up study of maxil-           overdentures retained by splinted and unsplinted im-
        lary overdentures on osseointegrated implants. Clin Oral               plants: a retrospective study. Int J Oral Maxillofac Implants
                                         io


        Implants Res 1993;4:39-46.                                             2001;16:259-266.
    35. Eckert SE, Carr AB. Implant-retained maxillary overden-            52. Abreu RT, Spazzin AO, Noritomi PY, Consani RL, Mesquita
        tures. Dent Clin North Am 2004;48:585-601.                             MF. Influence of material of overdenture-retaining bar with
                                iz



    36. Palmqvist S, Sondell K, Swartz B. Implant- supported max-              vertical misfit on three-dimensional stress distribution. J
        illary overdentures: outcome in planned and emergency                  Prosthodont. 2010 Aug;19(6):425-431.
        cases. Int J Oral Maxillofac Implants 1994;9:184-190.              53. Romero GG, Engelmeier R, Powers JM, Canterbury AA.
                Ed




    37. Petropoulos VC, Smith W, Kousvelari E. Comparison of                   Accuracy of three corrective techniques for implant bar
        retention and release periods for implant overdenture at-              fabrication. J Prosthet Dent 2000;84:602-607.
        tachments. J Oral Maxillofac Implants 1997;12:176-85.              54. Walmsley AD. Magnetic retention in prosthetic dentistry.
    38. Van Kampen F, Cune M, van der Bilt A, Bosman F. Re-                    Dent Update 2002; 29:428-433.
        tention and postinsertion maintenance of bar-clip, ball and        55. Takeshita S, Kanazawa M, Minakuchi S. Stress analysis of
        magnet attachments in mandibular overdenture treatment:                mandibular two-implant overdenture with different attach-
 IC




        an in vivo comparison after 3 months of function, Clin Oral            ment systems. Dent. Mater. J. 2011; 30: 928-934.
        Implants Res 2003;14:720-726.                                      56. Fitzpatrick B. Standard of care for the edentulous mandible:
    39. Naert I, Quirynen M, Hooghe M, Van Steenberghe D. A                    a systematic review. J Prosthet Dent. 2006 Jan;95(1):71-
        comparative prospective study of splinted and unsplinted               78.
C




        Branemark implants in mandibular overdenture therapy: a            57. Naert I,Gizani S,Vuylsteke M, et al. A 5-year randomized
        preliminary report. J Prosthet Dent 1994;71:486-492.                   clinical trial on the influence of splinted and unsplinted oral
    40. Naert I, Alsaadi G, Van Steenberghe D, Quirynen M. A 10-               implants in the mandibular overdenture therapy. Part I:
        year randomized clinical trial on the influence of splinted            Peri-implant outcome. Clin Oral Implants Res 1998;9:170-
©




        and unsplinted oral implants retaining mandibular overden-             177.
        tures: peri-implant outcome. Int J Oral Maxillofac Implants.       58. Quirynen M, Naert I, van Steenberghe D, Dekeyser C,
        2004 Sep-Oct;19(5):695-702.                                            Callens A. Periodontal aspects of osseointegrated fixtures
    41. Williams BH, Ochiai KT, Hojo S, Nishimura R, Caputo AA.                supporting a partial bridge. An up to 6-years retrospective
        Retention of maxillaty implant overdenture bars of different           study. J Clin Periodontol 1992;19:118-126.




    8                                                                                                Annali di Stomatologia 2012; III (1): 2-10
    Tissue-supported dental implant prosthesis (overdenture): the search for the ideal protocol. A literature review



    59. Ceruti P, Bryant SR, Lee JH, MacEntee MI. Magnet-re-                     ing of implants in completely edentulous patients.Int J Oral
        tained implant-supported overdentures: review and 1-year                 Maxillofac Implants. 2004;19 Suppl:76-91.
        clinical report. J Can Dent Assoc. 2010;76:a52.                      74. Weber HP, Morton D, Gallucci GO, Roccuzzo M, Cordaro
    60. Cehreli MC, Karasoy D, Kökat AM, Akça K, Eckert S. A                     L, Grutter L. Consensus statements and recommended
        systematic review of marginal bone loss around implants                  clinical procedures regarding loading protocols. Int J Oral




                                                                                                                     li
        retaining or supporting overdentures. Int J Oral Maxillofac              Maxillofac Implants. 2009;24 Suppl:180-183.
        Implants. 2010 Mar-Apr; 25(2) : 266-277.                             75. Gallucci GO, Morton D, Weber HP. Loading protocols for




                                                                                                                  na
    61. Batenburg RHK, Meijer HJA, Raghoebar GM. Treatment                       dental implants in edentulous patients. Int J Oral Maxillofac
        concept for mandibular overdentures supported by endos-                  Implants. 2009;24 Suppl:132-146.
        seous implants: A literature review. J Oral Maxillofac Im-           76. Testori T, Meltzer A, Del Fabbro M, Zuffetti F, Troiano
        plants 1998; 13:539-545.                                                 M, Francetti L, Weinstein RL. Immediate occlusal load-
    62. Menicucci G, Lorenzetti M, Pera P, Preti G. Mandibular                   ing of Osseotite implants in the lower edentulous jaw. A




                                                                                                               io
        implant-retained overdenture: finite element analysis of                 multicenter prospective study. Clin Oral Implants Res
        two anchorage systems. Int J Oral Maxillofac Implants                    2004;15:278-284.
        1998;13:369-376.                                                     77. Tawse-Smith A, Payne AGT, Kumara R, Thomson WM.




                                                                                        az
    63. Tokuhisa M, Matsushita Y, Koyano K. In vitro study of a                  Early loading of unsplinted implants supporting mandibular
        mandibular implant overdenture retained with ball, magnet,               overdentures using a one-stage operative procedure with
        or bar attachments: Comparison of load transfer and den-                 two different implant systems: A 2-year report. Clin Implant
        ture stability. Int J Prosthodont. 2003;16:128-134.                      Dent Relat Res 2002;4:33-42.




                                                                                      rn
    64. Federick DR, Caputo AA. Effects of overdenture retention             78. Kawai Y, Taylor JA. Effect of loading time on the success
        designs and implant orientations on load transfer charac-                of complete mandibular titanium implant retained overden-
        teris- tics. J Prosthet Dent. 1996;76:624-632.                           tures: a systematic review. Clin Oral Impl Res 2007;18:




                                                                           te
    65. Duyck J, Van Oosterwyck H, Van der Sloten J, et al. In vivo              399-408.
        forces on oral implants supporting a mandibular overden-             79. Attard NJ, Zarb GA. Immediate and early implant loading
        ture: The influence of attachment system. Clin Oral Inves-               protocols: a literature review of clinical studies. J Prosthet
        tig. 1999;3:201-207.                                                     Dent 2005 Sep;94(3):242-258.
    66. Mericske-Stern R, Piotti M, Sirtes G. 3-D in vivo force
                                                                In           80. Gatti C, Haefliger W, Chiapasco M. Implant-retained man-
        measurements on mandibular implants supporting over-                     dibular overdentures with immediate loading: a prospec-
        dentures. A comparative study. Clin Oral Implants Res.                   tive study of ITI implants. Int J Oral Maxillofac Implants
        1996;7:387-396.                                                          2000;15:383-388.
                                                   ni
    67. Gotfredsen K, Holm B. Implant-supported mandibular                   81. Chiapasco M, Gatti C. Implant-retained mandibular over-
        overdentures retained with a ball or bar attachments: a                  dentures with immediate loading: a 3 to 8-year prospec-
        randomized prospective 5-year study. Int J Prosthodont                   tive study on 328 implants. Clin Implant Dent Relat Res
                                           io


        2000;13:125-130.                                                         2003;5:29-38.
    68. Chao YL, Meijer HJA, Van Oort RP, Versteegh PA. The                  82. Mackie A, Lyons K, Thomson WM, Payne AG. Mandibular
        incomprehensible success of the implant stabilised over-                 two-implant overdentures: prosthodontic maintenance us-
                                 iz



        denture in the edentulous mandible: a literature review on               ing different loading protocols and attachment systems. Int
        transfer of chewing forces to bone sur- rounding implants.               J Prosthodont. 2011 Sep-Oct;24(5):405-416.
        Eur J Prosthodont Restor Dent 1995;3:255-261.                        83. Stoumpis C, Kohal RJ. To splint or not to splint oral implants
                 Ed




    69. Mericske-Stern R. Three dimensional force measurements                   in the implant-supported overdenture therapy? A system-
        with mandibular overdentures connected to implants by                    atic literature review. J Oral Rehabil. 2011 Nov;38(11):857-
        ball-shaped retentive anchors. A clinical study. Int J Oral              869.
        Maxillofac Implants 1998;13:36-43.                                   84. Roe P, Kan JY, Rungcharassaeng K, Lozada JL.Immediate
    70. Jemt T, Chai J, Harnett J, Heath MR, Hutton JE, Johns                    loading of unsplinted implants in the anterior mandible for
        RB, McKenna S, McNamara DC, Van Steenberghe D,                           overdentures: 3-year results.Int J Oral Maxillofac Implants.
 IC




        Taylor R, Watson RM, Herrmann. A 5-year prospective                      2011 Nov-Dec;26(6):1296-1302.
        multicenter follow-up report on overdentures supported by            85. Bressan E, Tomasi C, Stellini E, Sivolella S, Favero G,
        osseointegrated implants. Int J Oral Maxillofac Implants                 Berglundh T. Implant-supported mandibular overden-
        1996;11:291-298.                                                         tures: a cross-sectional study. Clin. Oral Impl. Res., 2011;
C




    71. Jemt, T. Implant treatment in resorbed edentulous upper                  10: 1111-1600.
        jaws. Clin Oral Implants Res 1993;4: 187-194.                        86. Widmark G, Andersson B, Andrup B, Carlsson GE, Ivanoff
    72. Jemt T, Chai J, Harnett J, Heath MR, Hutton JE, Johns                    CJ, Lindvall AM Rehabilitation of patients with severely
        RB, McKenna S, McNamara DC, Van Steenberghe D,                           resorbed maxillae by means of implants with or without
©




        Taylor R, Watson RM, Herrmann. A 5-year prospective                      bone grafts. A 1-year follow-up study. Int J Oral Maxillofac
        multicenter follow-up report on overdentures supported by                Implants 1998;13: 474–482.
        osseointegrated implants. Int J Oral Maxillofac Implants             87. Adell R, Eriksson B, Lekholm U, Brånemark PI, Jemt T.
        1996;11:291-298.                                                         Long-term follow-up study of osseointegrated implants in
    73. Chiapasco M. Early and immediate restoration and load-                   the treatment of totally edentulous jaws. Int J Oral Maxil-




    Annali di Stomatologia 2012; III (1): 2-10                                                                                               9
    D. Laurito et al.



        lofac Implants. 1990;5:347-359.                            91. Jemt T. Carlsson L. Boss A. Jorneus L. In vivo load mea-
    88. Murphy WM. Clinical and experimental bone changes              surements on osseointegrated implants supporting fixed or
        after intraosseous implantation. J Prosthet Dent. 1995;        removable prostheses: a comparative pilot study. Interna-
        73:31-35.                                                      tional Journal of Oral & Maxillofacial Implants. 6(4):413-
    89. Von Wowern N, Gotfredsen K. Implant-supported over-            417, 1991.




                                                                                                          li
        dentures, a pre- vention of bone loss in edentulous man-   92. Van der Bilt A, Burgers M, van Kampen FM, Cune MS.
        dibles? A 5-year follow-up study. Clin Oral Implants Res       Mandibular implant-supported overdentures and oral func-




                                                                                                       na
        2001; 12:19-25.                                                tion. Clin Oral Implants Res. 2010;21:1209-1213.
    90. Brånemark PI (September 1983). “Osseointegration and its   93. Balaguer J, García B, Peñarrocha M, Peñarrocha M. Sat-
        experimental background”. The Journal of Prosthetic Den-       isfaction of patients fitted with implant-retained overden-
        tistry 50 (3): 399-410.                                        tures. Med Oral Patol Oral Cir Bucal. 2011;16:204-209.




                                                                                                    io
                                                                             az
                                                                           rn
                                                                   te
                                                          In
                                              ni
                                     io
                            iz
                Ed
 IC
C
©




    10                                                                                      Annali di Stomatologia 2012; III (1): 2-10
