10.59987/ads/2018.4.146-161
The acronym Cad-Cam stands for Computer-Aided Design and Computer-Aided Manufacturing. In 1970, Dr. Francois Duret and his colleagues were the first to develop a Cad-Cam dental system, later named the Sopha system (Sopha BioConcept, Inc. Los Angeles). In the early 80s, a Swiss dentist, Dr. Werner Mörmann, and an Italian electronic engineer, Eng. Marco Brandestini developed the first Cad- Cam chairside system for dental use, known as the Cerec system (Chairside Economical Restoration of Esthetic Ceramics). Anderson and his colleagues attempted to create titanium caps using Cad-Cam technology. In 1983, they introduced a Cad- Cam technology to mill implant restorations in titanium and cover it with ceramic or composite. This system later became known as the Procera system. Computer- Aided Design (CAD) technology of computerized systems to create, modify, analyze and enhance the design process. Computer-Assisted Manufacturing (CAM) is an automated system that organizes manages, and controls manufacturing process. Together Cad-Cam process has three cycles: 1. The data acquisition. 2. Data elaboration and design processing. 3. Manufacturing of the appliance. An intraoral scanner can capture the optical impression of soft and hard tissue intraorally. Alternatively, models fabricated from analog (traditional) impressions can be scanned and digitalized with a scanner. Doctors will transfer accumulated data to the dental laboratory, where dental technicians design and manufacture the prosthesis. Especially in electro-welded immediate load implantology (characteristic of the Italian school of implantology) the digital flow optimized the entire rehabilitation process. The Benefits of Using a CAD-CAM technology. - Effective communication with the patient. - Greater patient comfort. - Better diagnosis. - Easy storage of data. - A scanner is far less invasive compared to traditional dental impressions. - The possibility of creating and reproducing high quantities dental models. - The fast transfer of files via the internet to a laboratory situated far away. - The reduction of corrections and remakes, high production workflow. - Saving time and costs of the entire restoration process. - The decrease in non-recyclable materials. - The possibility of planning and simulating implant surgery using designated software, merging the intraoral scanning data is 3D CAT radiography (DICOM). Limitations of Using a CAD-CAM technology: - Initial Investment. - Learning Curve. - Continuous software updating. Computer-aided design (CAD) and computer-aided manufacturing (CAM) are innovative digital systems capable of scanning prepared teeth intended for receiving crowns, bridges, inlays, and other restorations. With the advent of technologies and potential applications, dentistry is one application area that has gained the highest market share in the last few years. CAD/CAM systems offer a better, faster, and more convenient method for fabricating dental restorations. Many dental schools adopted CAD/CAM technology intended for education and clinical patient care. CAD/ CAM technology improves the experience of both the professional and patient by reducing patient visits, increasing efficiency, and contributing to a positive practice environment and clinical productivity. Such factors ultimately contribute to the overall market growth and revenue during the forecast period
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Annali di stomatologia
Implants Surgical Guides
Intra-oral scanning and CAD/CAM prosthesis fabrication
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Original Article
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2022-08-09
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146-161
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P. Diotallevi
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Implants Surgical Guides
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Intra-oral scanning and CAD/CAM prosthesis fabrication
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                                                                                                  Original article

Intra-oral scanning and CAD/CAM
prosthesis fabrication


Enrico Moglioni1                                             3. Manufacturing of the appliance.
Luca dal Carlo2                                              An intraoral scanner can capture the optical impres-
Mike Shulman2                                                sion of soft and hard tissue intraorally. Alternatively,
Marco Pasqualini2                                            models fabricated from analog (traditional) impres-
Franco Rossi2                                                sions can be scanned and digitalized with a scanner.
Carlo Cosma2                                                 Doctors will transfer accumulated data to the den-
Flavio Lico2                                                 tal laboratory, where dental technicians design and
Paolo Diotallevi3                                            manufacture the prosthesis.
                                                             Especially in electro-welded immediate load implan-
                                                             tology (characteristic of the Italian school of implan-
1
    Presidente ARASS (Associazione per la Ricerca e le       tology) the digital flow optimized the entire rehabili-
    Attività Sociali in Stomatologia)                        tation process.
    Association for Research and Social Activity in Stoma-   The Benefits of Using a CAD-CAM technology.
    tology Rome Italy                                        - Effective communication with the patient.
2
    Medico odontoiatra                                       - Greater patient comfort.
3
    Medico radiologo                                         - Better diagnosis.
                                                             - Easy storage of data.
                                                             - A scanner is far less invasive compared to tradi-
Corresponding author:                                             tional dental impressions.
Enrico Moglioni                                              - The possibility of creating and reproducing high
Presidente ARASS (Associazione per la Ricerca e le At-            quantities dental models.
tività Sociali in Stomatologia)                              - The fast transfer of files via the internet to a lab-
Association for Research and Social Activity in Stomato-          oratory situated far away.
logy Rome Italy                                              - The reduction of corrections and remakes, high
3388752989                                                        production workflow.
enrico.moglioni@fastwebnet.it                                - Saving time and costs of the entire restoration
                                                                  process.
                                                             - The decrease in non-recyclable materials.
Abstract
                                                             - The possibility of planning and simulating im-
The acronym Cad-Cam stands for Computer-Aid-                      plant surgery using designated software, merg-
ed Design and Computer-Aided Manufacturing. In                    ing the intraoral scanning data is 3D CAT radiog-
1970, Dr. Francois Duret and his colleagues were                  raphy (DICOM).
the first to develop a Cad-Cam dental system, later          Limitations of Using a CAD-CAM technology:
named the Sopha system (Sopha BioConcept, Inc.               - Initial Investment.
Los Angeles). In the early 80s, a Swiss dentist, Dr.         - Learning Curve.
Werner Mörmann, and an Italian electronic engineer,          - Continuous software updating.
Eng. Marco Brandestini developed the first Cad-              Computer-aided design (CAD) and computer-aided
Cam chairside system for dental use, known as the            manufacturing (CAM) are innovative digital systems
Cerec system (Chairside Economical Restoration of            capable of scanning prepared teeth intended for re-
Esthetic Ceramics). Anderson and his colleagues              ceiving crowns, bridges, inlays, and other restora-
attempted to create titanium caps using Cad-Cam              tions. With the advent of technologies and potential
technology. In 1983, they introduced a Cad- Cam              applications, dentistry is one application area that has
technology to mill implant restorations in titanium          gained the highest market share in the last few years.
and cover it with ceramic or composite. This system          CAD/CAM systems offer a better, faster, and more con-
later became known as the Procera system. Comput-            venient method for fabricating dental restorations.
er-Aided Design (CAD) technology of computerized             Many dental schools adopted CAD/CAM technology
systems to create, modify, analyze and enhance the           intended for education and clinical patient care. CAD/
design process. Computer-Assisted Manufacturing              CAM technology improves the experience of both the
(CAM) is an automated system that organizes man-             professional and patient by reducing patient visits,
ages, and controls manufacturing process.                    increasing efficiency, and contributing to a positive
Together Cad-Cam process has three cycles:                   practice environment and clinical productivity. Such
1. The data acquisition.                                     factors ultimately contribute to the overall market
2. Data elaboration and design processing.                   growth and revenue during the forecast period.
Annali di Stomatologia 2018; IX (4): 146-161                                                                            146
      Intra-oral scanning and CAD/CAM prosthesis fabrication

      Keywords: CAD/CAM, Intraoral Scanner, One-piece,                   1. The data acquisition.
      Immediate loading, Intraorally welded, Implants                    2. The data elaboration, design processing.
      Surgical Guides.                                                   3. Manufacturing of the appliance.

      Introduction                                                       The traditional method
      The acronym Cad-Cam stands for Computer-Aided De-                  The traditional method.
      sign and Computer-Aided Manufacturing.                             For a fixed metal-ceramic prosthesis manufacturing:
      Computer-Aided Design (CAD) technology is applied to               - Dental Impression
      computerized systems to facilitate the creation, modifi-           - Plaster Model
      cation, analysis and enhancement of a design.                      - Modeling of substructure in wax
      Computer-Assisted Manufacturing (CAM) is an automat-               - Casting
      ed system that organizes, manages and controls manu-               - Metal preparation
      facturing operations (1).                                          - Ceramic application
      In 1970, Dr. Francois Duret and his colleagues were the            All these stages are 100% manual operations. All work
      first to develop a Cad-Cam dental system, later named the          depends on technicians and all of them can potentially
      Sopha system (Sopha BioConcept, Inc.Los Angeles) (2).              flaw the final product. With different quality control lev-
      In the early 80s, a Swiss dentist, Dr. Werner Mörmann,             els, these defects could be detected relatively late; this
      and an Italian electronic engineer, Eng. Marco Brandes-            might prolong the production times.
      tini developed the first Cad-Cam chairside system for              when detected and corrected (Fig. 2).
      dental use, known as the Cerec system (Chairside Eco-              Collateral damage or side-effects of inappropriately pro-
      nomical Restoration ofEsthetic Ceramics) (3).                      duced laboratory work:
      Anderson and his colleagues attempted to create tita-              - open margins cause secondary decay and gingival
      nium caps using Cad-Cam technology. In 1983, they                       inflammation, decreasing the teeth and prosthesis’s
      introduced a Cad- Cam technology to mill implant res-                   lifespan, ultimately bone loss;
      torations in titanium and cover it with ceramic or com-            - the nonpassive fit of the prosthesis can move teeth
      posite. This system later became known as the Procera                   to compensate for the deficiency.
      system (4).                                                        However, overloaded implants will react differently than
      Computers are substitutes for regular hand-operated                the teeth, active lateral forces will cause bone loss and
      activity, and trained dental technicians, making the work-         ultimately even implant loss.
      flow more expeditious, cost-effective, and predictable.            Natural teeth can move axially by 25-100µ and 56-108µ
      Cad-Cam has three cycles (Fig. 1):                                 laterally (5). Prostheses on implants move more than




      Figure 1. Acquisition of data, elaboration of data and manufacturing of the device.

147                                                                                         Annali di Stomatologia 2018; IX (4): 146-161
E. Moglioni et al.




                                                                                           Figure 2. Dimensional changes
                                                                                           in elastomer impression materi-
                                                                                           al can be duplicated as plaster
                                                                                           modeling errors, ultimately pro-
                                                                                           ducing prostheses with defects.



3-5µ in an axial direction and 10-50µ in a lateral direc-
tion; implants will fail if moving further (6). An incorrect
prosthesis fit generates stress that can negatively affect
the bone-implant interface and, therefore, become the
first step towards an implant’s dis-integration (7). The
most common prosthetic complications, the screw loos-
ening or fracture, can be related to a nonpassive, forced
prosthesis insertion (8).
If a titanium bar is seated with extra stress (nonpassive
fitting) on welded abutments, it will cause an unbalanced
forces distribution (9)
                                                               Figure 4. Scan of one-phase implant abutments level.
Analog, Traditional intraoral impressions
The dental impression material can inaccurately impress        CHART 1. Compares manufacturing processes for a dif-
a titanium bar welded to the monolithic implants’ abut-        ferent type of restoration. Traditional workflow compared
ments. This mono-block structure has undercuts (10).           to CAD-CAM technology.
Elastomeric materials impressing the undercut, are de-         CAD-CAM technology eliminates some steps as well as
formed upon withdrawal, may not ideally resemble the           70% manual labor (Fig. 5).
contour, and when it is reproduced on the model, it will
create inaccuracies.
                                                               Digital flow in implant prosthetics
The time between taking the impressions and casting            Reverse Engineering
the plaster model also can affect the accuracy because
of the material’s dimensional stability.                       The term “reverse engineering” refers to the techniques
Small and thin abutments may give the technicians a            and technologies which enable a virtual product to be
hard timereproducing them on the model (11).                   created from a real one. Reverse-engineering can rec-
When comparing analog to digital impressions, the au-          reate the object or create a similar object with added en-
thors suggest that most of the challenges described            hancements to reconstruct an existing object’s virtual or
above areeliminated (12)                                       CAD model (13). In dentistry, these techniques are used
                                                               to transfer a patient’s anatomy into a calculator. Three
                                                               general steps are common to all reverse-engineering
Intraoral scanners
                                                               efforts. They include:
Intraoral scanners (IOS) are devices used for capturing        - Information extraction. The reverse-engineered ob-
direct optical impressions. The hard and soft tissues im-          ject is studied, information about its design is extract-
ages, captured by imaging sensors and scanning soft-               ed and it is examined to determine how the pieces fit
ware, generatea 3D model.                                          together.
Taking dental impressions and the fabrication models can       - Modeling. The collected information is summarized
be done with an intraoral scanner and 3D printer (Fig. 3).         into a model. Information is specific to the original
Digital dental impressions are the first step (Fig. 4).            and abstracts it into a general model that can design
                                                                   new objects.
                                                               - Review. Reviewing the model and testing it in various
                                                                   scenarios ensures a realistic abstraction of the origi-
                                                                   nal object or system. Once it is tested, the model can
                                                                   be implemented to reengineer the original object.
                                                               Computer-aided design (CAD) is a reverse-engineering
                                                               technique used to recreate a manufactured part. It in-
                                                               volves producing 3D images of the part so it can be
                                                               remanufactured.A coordinate measuring machine meas-
                                                               ures the part, and as it is measured, a 3D wireframe
                                                               image is generated using CAD software and displayed
                                                               on a monitor. Reverse-engineering techniques eliminate
Figure 3. Intraoral Scanner.                                   some of the guesswork.

Annali di Stomatologia 2018; IX (4): 146-161                                                                                   148
      Intra-oral scanning and CAD/CAM prosthesis fabrication




      Figure 5 The main manufacturing processes for the creation of metal-ceramic ormetal-free crowns.


      Digital dental workflow                                        Dentists scan the dental/implant surfaces and/or of the
                                                                     scan-body implants and adjacent anatomical structures,
      -   Digitalization done by the dentist; the digital impres-    the scanner reproduces the morphology of the dental
          sion of the patient’s soft and hard tissue. Scanning       arch with elements. Typically, hundreds of scans are
          of the preparation. Implant/abutment direct scan or a      necessary to capture all of the information from vari-
          scanning body. Scanning by the dental technician           ous sides and angles. These scans are then integrated
          a plaster model obtained from a traditional impres-        through a common reference system known as align-
          sion or scanning the impression also transferring          ment/registration.
          articulated models into the virtual articulator in the     Finally, the individual scans are merged to re-create the
          laboratory.                                                final model. This entire process of bringing together the
      -   CAD designing of a prosthesis.                             individual scans and merging them is known as a 3D
      -   The technician is milling the substructure or mono-        scanning pipeline. The dotted image reproduces the
          lithic prosthesis.                                         morphology of the scanned dental arch. At this point, it
      -   Application of the veneering material, finishing, and      is necessary for the cloud of points to transform into a
          polishing.                                                 surface. To do this, the software undertakes the joining
      -   Dentist delivers the prosthesis to the patient.            of the single discrete points, according to a mathemati-
                                                                     cal formula, measuring the distance between them and
      3D Scanner                                                     reconstructing a grid formed by a series of minuscule
      All 3D scanners are instruments to scan an object and          polygons (generally triangles) (Fig. 6).
      uselight and specific sensors to convert optical data, the
      so-called “cloud of points” converting it into a 3D model.
      The basic principle is the emission of a light signal (Laser
      or structured light) by an emitter and the receiver’s return
      signal’s reception (14).
      In dentistry, the most common scanners are the so-
      called “triangulation scanners.”
      Typically, a 3D scanner consists of a source of light, one
      or more video cameras. 3D scanners essentially create
      a digital copy of a real-world object. This digital copy of
      the 3D file can then be edited and 3D printed. Also, a
      3D file can be used for further 3D modeling processes.
      Nowadays, in this 21st-century, Engineers are using this
      technology for reverse engineering processes. 3D scan-         Figure 6. The software connects the points in the cloud, re-
      ner files are generally compatible with CADsoftware and        constructing a grid formed of triangles, calculating the area,
      3D printing slicer software.                                   and defining its filling in.

149                                                                                     Annali di Stomatologia 2018; IX (4): 146-161
E. Moglioni et al.

It is possible to calculate the three-dimensional position.        When the scanner recognizes a curved surface, such as
The light is reflected through trigonometry, measuring             the cylindrical bar welded to the implant abutments, it
the angle and distance between the video and the light             immediately increases the number of triangles. Although
source (which forms the scanner head). This principle of           a large number of points, on one hand, better define the
measurement is known as “triangulation.” It is possible to         scanned area, on the other hand, this does not neces-
obtain an in-depth image through scanning.                         sarily guarantee accuracy and precision.
Having a series of polygons created by a wireframe, the            Accuracy: represents the error/discrepancy between the
software can calculate the single triangles’ area and fill         recorded measurement and its true value (accepted as
themin. The in-depth image is an image in which the 3D             accurate). It is an error that supersedes the acquired
coordinatesof the object’s surface are memorized.                  data; where measurements of the same value are re-
A solid structure is recreated and forms the virtual model,        peated, it can be considered the distance between the
and accuracy depends on the dimensions and number of               average and truemeasurements.
triangles. Therefore, it is based on the number of refer-          Precision: is represented by the dispersion of the meas-
ence points initially recorded by the scanner—the more             urements around their average. It enables an estimation
detailed the scan, the more detailed reconstruction.               of the casual error component, considering several re-
STL file formats encode information in order to store it           peated measurements. Precision means the ability to
on a computer. When it comes to 3D printing, the STL               repeat the same measurement several times. So, an
(Standard Triangulation Language) file format is the               already precise machine simply needs to be set accord-
most commonly used.                                                ingly to achieve maximum accuracy (Fig. 7).
The scanners that are available on the market are con-
tactless optical technologies, such as:                            Transfer of digital data to the laboratory
- Confocal microscopy.
- Photogrammetry.                                                  Once the optical impression is recorded and filed, the
- Active and passive stereo display.                               STL file is sent directly to the designated laboratory
- Triangulation.                                                   (Fig. 8).




Figure 7. Examples of accuracy and precision (trueness and precision) with three different scanners.


Scanner precision
The international standards regarding the international
regulations ISO 10360-1-9 2013 (15) Geometrical Product
Specifications (GPS) (Quality control Test for coordination
of the measuring machines (CMM); while for dentistry, the
regulation is ISO 12836:2012 (16) (Dentistry - Digitizing
devices for Cad-Cam systems for indirect dental restora-
tions- test methods for assessing accuracy).
The parameters linked to three-dimensional measuring are
resolution, accuracy, and precision; that is, measurement
uncertainty. These can be defined in the following way:
(Maximum) Resolution: generally consists of the most
minute variations in measurement possible to measure.
The cloud density of points is proportional to the resolu-
tion: it affects the distance between the recorded points          Figure 8. Enhanced impression sent by internet to the lab-
and describes geometrical details of small dimensions.             oratory.

Annali di Stomatologia 2018; IX (4): 146-161                                                                                    150
      Intra-oral scanning and CAD/CAM prosthesis fabrication

      The optical impression of welded/unwelded
      one phase immediate load implants
      We are working with the one-piece implant/abutment
      (17).

      Preparation of implant abutments
      During the preparation, it is necessary to increase the in-
      terproximal space so that the cameras’ light can stream
      freely and, therefore, precisely record the details. The
      one-piece implant/abutments, smaller than two-piece
      abutments, facilitates the camera capturing (Fig. 9-10).

      Gingival retractions
      Once the implants placements, preparation, and ad-
      justments of the abutments are completed, the gingival
      margin needs to be verified and recorded; the gum
      needs to be repositioned or retracted. Gingival retrac-
      tion can be accomplished using retraction cords; in some
      cases, a laser can be a helpful instrument.
      Figures 11 and 12. Three implants, one submerged, and
      two one-piece implants were welded together in this clin-
      ical case. After integration, the welded bar was removed,
      and the three implants were prepared for impressions.
      Gingival cord/retractors were placed, and digital impres-
      sions were taken.
      The upper jaw was scanned pre-operatively, where the
      abutments were positioned; this area was cropped from          Figure 11. Removing the welded bar, verifying the implant
      the image. The prepped abutments are scanned, and              stability and the refining margins of the abutments.
      the software will re-impose the abutments into the previ-
      ously cropped area (Fig. 13).




                                                                     Figure 12. The two gingival retractors/cords were left during
                                                                     the digital impression acquisition (clinical case of figure 11).



      Figure 9. Intra-oral scanning of the abutment portion of the
      one- piece implants was prepared similar to natural teeth.




      Figure 10. The structure of the one-piece implant abutment     Figure 13. The eliminated area will be reproduced through
      provides easier access for scanning.                           the rescanning of the area with the placed abutments.

151                                                                                      Annali di Stomatologia 2018; IX (4): 146-161
E. Moglioni et al.

The acquired image part is cropped, and this area            Digital impressions of implants
(cropped) is rescanned; It saves time because the sec-
ond scan does not include the entire jaw. As this            The digital impression of the implants connected with a
area is rescanned, the new partial second scan will          bar is a challenging procedure in the restorative stage
re-impose the previously cropped part of the digital im-     (18).
pression.                                                    Temporary PMMA prosthesis cemented on immediately
The full upper jaw impression, with the implant abut-        inserted and connected implants. It will provide a tempo-
ments and soft tissue, is reconstructed as a model. Once     rary patient’s function for the duration of the integration
the second scan is complete, it can be articulated with      of the implant (19-21) (Fig. 15).
the opposing jaw, the occlusion is scanned and sent          The digital impression of the temporary prosthesis is tak-
(emailed) to the laboratory (Fig. 14).                       en for record-keeping purposes. It can be used as a part
Working with an intraoral scanner, taking digital records    of the permanent impression later on (Fig. 16).
gives us:                                                    This model will be used in the laboratory as a perma-
The entire upper and lower jaw with the functional tem-      nent prosthesis guideline. Occlusion, horizontal and
porary prosthesis.                                           vertical overjets are verified, and the technician can
The recording confirmed occlusion.                           build the final prosthesis with the outline based on the
The possibility for the second fragment impression to be     provided data.
re-imposed and to be taken any time later (a day or a        The temporary is removed and the implant abutments
week or longer).                                             modifiedas needed to define the finishing line (Fig. 17).
The bite registration taken for the full mouth without the
need to be retaken. Once the fragment is re-imposed,         Size control
theocclusal record used is the one saved before.             The preoperative model, the temporary prosthesis mod-
The full-arch impression/model can be duplicated and         el, will be used in the laboratory as a permanent prosthe-
saved.                                                       sis prototype.




                      Figure 14. Bite registration record.

Annali di Stomatologia 2018; IX (4): 146-161                                                                               152
      Intra-oral scanning and CAD/CAM prosthesis fabrication

                                                                        Occlusion, horizontal and vertical overjects are verified,
                                                                        and the technician can create the final prosthesis out-
                                                                        line based on provided data (Fig. 18).
                                                                        We can verify that both abutments and the welded bar
                                                                        are within limits to maintain a proper prosthesis outline.
                                                                        If the bar position is compromised, the bar can be re-
                                                                        welded and the impression retaken. Intraoral scanning
                                                                        can verify the miss- angulated abutment, the compro-
                                                                        mised path of insertion and even the presence of an
                                                                        undercut; all these can be corrected and the impres-
                                                                        sion retaken. This correction can be done with almost
                                                                        no time wasted, unlike using an analog, older technique
                                                                        (Fig. 19).
                                                                        With a welded bar (22, 23) on the abutments, undercuts
                                                                        are frequent, especially junction points. With the digital
                                                                        impression, it can be detected and eliminated almost
                                                                        instantly.

                                                                        Design of closing margins
                                                                        Digital/optical impression reveals the finishing line imme-
                                                                        diately, and if it needs to be redefined, it can be done at
                                                                        that time (Fig. 20).
                                                                        Another function of the software is to personally trace
                                                                        the prosthesis finishing line, the margins of the resto-
      Figure 15.
                                                                        ration.




      Figure 16. The optical impression/ model of the temporary prosthesis after healing.


                                                                        The margin is highlighted with a colored line, memoriz-
                                                                        ing and saving it as a file. The welded bar is rested on
                                                                        the edentulous area, and we can draw the equatorial
                                                                        margin on the bar. The equator indicates the line which
                                                                        the prosthetic structure must not bypass.
                                                                        Continuing with the digital flow, the software will visual-
                                                                        ize the acquired data in 3D; the technician will design a
                                                                        dental restoration in 3D (Fig. 21).

                                                                        The Benefits of Using an Intra-Oral Scanner
                                                                        - Effective communication with the patient.
                                                                        - Greater patient comfort.
                                                                        - Better diagnosis.
                                                                        - Easy storage of data.
      Figure 17. Illustration of the optical impression with welded     - A scanner is far less invasive compared to traditional
      one-phase implants at the laboratory, the workflow continues.         dentalimpressions.

153                                                                                         Annali di Stomatologia 2018; IX (4): 146-161
E. Moglioni et al.




Figure 18. Control and immediate verification of the available sizes for the correct illustration of the prosthesis.




Figure 19. Assessing the presence of an undercut when it is
determined can be immediately eliminated.




Figure 20. Outlining the finishing line or the restoration mar-      Figure 21. Design and illustration of the prosthetic resto-
gins on the implant abutments.                                       rations.

Annali di Stomatologia 2018; IX (4): 146-161                                                                                       154
      Intra-oral scanning and CAD/CAM prosthesis fabrication

      -  The possibility to create and reproduce high quan-          As artificial intelligence algorithms become more and
         titiesdental models.                                        more advanced, the increasing precision of the elements
      - The fast transfer of files via the internet to a             built with AI’s help and its reliability make it irreplaceable
         laboratorysituated many kilometers away.                    in today’s life.
      - The reduction of corrections and remakes, high               Today, the practitioners are divided into a few groups,
         productionworkflow.                                         utilizing surgical guides, as computer-guided procedures
      - Saving time and costs of the entire restoration pro-         and computer-assisted ones.
         cess.                                                       Once the CBCT acquisition was completed, the operator
      - The decrease in non-recyclable materials.                    studied the radiographic images, checking for possible
      - The possibility of planning and simulating implant           pathologies, examining vital structures.
         surgery using designated software, merging the in-          To eliminate any possible misreading, it is recommend-
         traoral scanning data is 3D CAT radiography (file           ed that the Maxillofacial radiologist evaluates the image.
         DICOM).                                                     The software used to design and illustrate the treatment
      There are some Limits:                                         planning, including implant placements and bone aug-
      - Initial Investment.                                          mentations, usually comes with CBCT. Various third-party
      - Learning Curve.                                              softwares offer comprehensive CBCT review, 3D recon-
      - Continuous software updating.                                struction, treatment planning, and surgical guides design.
      - The camera’s light may have limitations when a               To transfer the data, build surgical guides or temporary
         shiny object needs to be scanned. Oral fluids and           restorations, we need to merge radiographic data. It gen-
         gum covering the margin line have to be eliminated.         erally comes in DICOM format files, with hard and soft
                                                                     tissue images obtained from the optical intraoral scan in
      CAD technology, the different components of the pros-
                                                                     STL format. To merge these files (generated from CBCT
      thesis processing, two distinct working techniques:
                                                                     radiographic data, 3D anatomical model and soft and
      The subtractive technique - CNC.
                                                                     hard tissue scanned with optical scan) and fabricate pa-
      The milling machines are equipped with different drills
                                                                     tient-matched surgical guides, an additional software is
      for various materials. They can be used to cut solid
                                                                     needed. With software, one can merge the digital radio-
      disks. Alternatively, a soft disk (a green stage) will later
                                                                     graphic scan with the optical intraoral scan by choosing
      besintered to become hard (24).
                                                                     close matching points. The software will re- impose and
      The additive technique - AM
                                                                     merge the images.
      The structure is built layer by layer, known as Additive
                                                                     Treatment planning is implemented in one of many
      Manufacturing (25).
                                                                     methods. The suggested one includes placing the miss-
      Today, CAD/CAM technology has become irreplaceable,
                                                                     ing tooth or teeth on the virtual model, then placing an
      yet the last word is human intellect and the human hand.
                                                                     implant and abutment.
      Surgical guides                                                Once implants are placed into the desired position, an
                                                                     operator can build a surgical guide using different reten-
      As Oral Implantology is becoming a standard treatment          tion methods.
      modality, more and more doctors are adding it to their         The guide can be teeth retained or bone retained de-
      treatment choices.                                             pending on the patient’s condition. The bone retained
      Artificial intelligence has also become part of our pro-       surgical guard has to be fixated with pins, slots, or pin-
      fessional and social lifestyles. Bringing elements of ar-      holes; they are a part of the surgical guide design.
      tificial intelligence into our everyday lives changed it at    The operator builds a surgical guide over the implants, vir-
      different levels. As we are implying in oral implantology,     tually placed on the reconstructed radiographic image and
      one can say that 3D treatment planning and treatment           soft and hard tissue model obtained from the optical scan.
      performance has improved dramatically.                         Surgical sleeves are incorporated into the surgical guide.
      Treatment times, accuracy, and outcome benefited from          Different companies offered their surgical kits with corre-
      artificial intelligence engagement.                            sponding surgical sleeves and implant drivers for a fully
      As we move along with new technologies, one should             guided procedure.
      understand the benefits and limitations, to guarantee the      In a case, the operator chose computer-assisted tech-
      proper application.                                            niques; the surgical guide is utilized for partial guidance:
      Different synopses are as follow: computer-guided sur-         like osteotomy positioning.
      gery, computer-assisted surgery.                               The operator will be thoroughly guided from the first oste-
      It is up to an operator to decide who is what. Without         otomy to the final depth, width and implants (abutments
      prejudice we study the main principles to cover both           optional) placement in the complete computer-guided
      options, and the operator will have to choose.                 surgery.
      CBCT, initially used for diagnostic purposes, is the best      In the situation where bone augmentation is required,
      for assessment, diagnosis, treatment planning and              operator-guided techniques are preferred by the authors.
      guiding the surgical and prosthodontic means.                  The tolerance of surgical instruments has advanced and
      The 3D reconstruction becomes more and more precise            the drills’ lateral movements (vibrations) were significant-
      and predictable in education, fabricating surgical and         ly reduced. The software imaging devices and printing
      prosthetic appliances.                                         devices improved further, all ameliorating a lot the pro-
      Virtual treatment planning, implant placement, bone re-        cedure’s accuracy.
      duction, or bone augmentation can be guided or con-            Prediction: soon most of the procedures will be fully
      trolled with the surgical guide’s utilization.                 computer- guided with high clinical success (Fig. 22-30).
155                                                                                     Annali di Stomatologia 2018; IX (4): 146-161
E. Moglioni et al.




 Figure 22. The software can evaluate and illustrate the treatment planning, implant placements and bone augmentations,
 usually included with CBCT.




 Figure 23. CBCT for diagnostic purposes.

Annali di Stomatologia 2018; IX (4): 146-161                                                                              156
      Intra-oral scanning and CAD/CAM prosthesis fabrication




         Figure 24. Virtual treatment planning on a generated model. Implants are placed into the desired position.




         Figure 25. The operator builds a surgical guide.

157                                                                                       Annali di Stomatologia 2018; IX (4): 146-161
E. Moglioni et al.


 A                                                                      B




Figure 26. A. Designed surgical guide. B. Surgical guide




Figure 27. Surgical sleeve.                                        Figure 28. Implant drivers (mount).
(RealGUIDE 5.0, 3DIEMME Srl, Italy)                                (RealGUIDE 5.0, 3DIEMME Srl, Italy)




Figure 29. The report, the estimated bone quality and possible collision situations.


Annali di Stomatologia 2018; IX (4): 146-161                                                             158
      Intra-oral scanning and CAD/CAM prosthesis fabrication




       Figure 29. Continua.




       Figure 29. Continua.


159                                                            Annali di Stomatologia 2018; IX (4): 146-161
E. Moglioni et al.




     Figure 30. Completed surgical part




References                                                           11. P. Oral Implantology today: Surgical protocol, Historical
                                                                         facts, Diagnostic imaging, Biomechanical notes. Implants
1.  Carfagna G. CAD/CAM 3D. Studi di progettazione e produz-             n° 4 – 2016 44-51.
    ione di un componente meccanico Edizioni Savine (2010).          12. Picton DC, Creasey SJ Some causes of failure of crowns,
2. Duret F.,Preston J.D. (1991). “CAD/CAM imaging in dentist-            bridges and dentures. J Oral Rehabil. 1989 Mar;16(2):
    ry.” Curr Opin Dent 1(2): 150-154.                                   109-18.
3. Mormann W.H. (2004). “The origin of the Cerec method: a           13. Christensen GJ (2008) Will digital impressions eliminate the
    personal review of the first 5 years.” Int J Comput Dent 7(1):       current problems with conventional impressions? J Am Dent
    11-24.                                                               Assoc 139(6): 761– 763.
4. Andersson M., Carlsson L., Persson M.,Bergman B. (1996).          14. Guidi G., Russo M., Beraldin JA. Acquisizione 3D e model-
    “Accuracy of machine milling and spark erosion with a CAD/           lazione poligonale 2010 McGraw-Hill Companies srl Milano.
    CAM system.” J Prosthet Dent 76(2): 187- 193.                    15. Persson A, Andersson M, Oden A, Sandborgh-Englund G
5. Sahin S, Cehreli MC. The significance of passive framework            A three- dimensional evaluation of a laser scanner and a
    fit in implant prosthodontics: current status. Implant Dent          touch-probe scanner. 2006, The Journal of Prosthetics Den-
    200110: 85-92.                                                       tistry, Vol. 95, issue 3 p. 194-200.
6. Kim Y, Oh TJ, Misch CE, Wang HL. Occlusal considerations          16. ISO 10360-9:2013 Geometrical product specifications
    in implant therapy: clinical guidlines with biomechanical ra-        (GPS) -- Acceptance and reverification tests for coordinate
    tionale. Clinical Oral Implants Res 2005;16: 26-35.                  measuring systems (CMS) -- Part 9: CMMs with multiple
7. Sahin S, Cehreli M, Yalcin E. The influence of functional             probing systems.
    forces on the biomechanics of implant-supported prosthe-         17. ISO 12836:2012 specifies test methods for the assessment
    ses. A review J Dent 2002;30: 271-282.                               of the accuracy of digitizing devices for computer-aided de-
8. Sones AD. Complications with osseointegrated implants. J              sign/computer-aided manufacturing (CAD/CAM) systems
    Prosthet Dent 1989;62: 581-585.                                      for indirect dental restorations.
9. Moglioni E, Diotallevi P, Pezzuti E, Pasqualini M, Ferrante       18. Moglioni E, Diotallevi P, Pierazzini A, Pezzuti E, Lagana’ G.
    G, Floris Pl. Success rates in subjects rehabilitated with im-       L’implantologia orale oggi: protocolli chirurgici, cenni storici,
    mediate loading technique on according to AISI guidelines.           diagnostica per immagini e note di biomeccanica. 2005 Boll.
    Ann. Stom. 2008; LVII (1-2):19-23.                                   SMO 25:4-9.
10. Moglioni E, Pezzuti E, Grotowski T, Dal Carlo L, Shulman         19. Dal Carlo L, Pasqualini Me, Mondani P.M, Rossi F, Moglioni
    M, Diotallevi                                                        E, Shulman M. Mondani intraoral welding: historical process

Annali di Stomatologia 2018; IX (4): 146-161                                                                                                 160
      Intra-oral scanning and CAD/CAM prosthesis fabrication

          and main practical applications. Journal of Biological Reg-           of periodontal disease. Journal of Biological Regulators &
          ulators & Homeostatic Agents. Vol. 31,n°2 (S1), 233-239               homeostatic Agents. Vol. 32, n°2 /S1), 27-34 (2018).
          (2017).                                                         23.   Dal Carlo L, Pasqualini Me, Rossi F, Meynardi F, Moglioni
      20. Rossi F, Pasqualini Me, Moglioni E, Meynardi F. Impianti              E, Riccardi L, Fanali S, Shulman M. Saldatrice endorale di
          postestrattivi one-piece a carico immediato nel settore fron-         Mondani. Principali applicazioni pratiche. Doctor Os 2017
          tale superiore con deficit osseo vestibolare. Doctor Os XIII          XXVIII;05:36-47.
          (7) Sett. 2013:779-787.                                         24.   Dal Carlo L, Squillantini P. Shulman M, Winkler S, Moglioni
      21. Rossi F, Pasqualini Me, Carinci F, Meynardi F, Diotalle-              E, Donati R, Pasqualini Me, Rossi F. Case Report: Imme-
          vi P, Moglioni E, Fanali S. “One-piece” immediate-load                diate loading of intraorally welded implants. Implants n° 3
          post-extraction implants in labial bone deficient upper               – 2016 – 8-13.
          jaws. Annals of Oral &Maxillofacial Surgery 2013 Apr            25.   Van Noort R. “The future of dental devices is digital.” Dent
          01;1(2):14.                                                           Mater 2012; 28(1): 3-12.
      22. Meynardi F, Lauritano D, Pasqualini Me, Rossi F, Griv-          26.   Beuer F., Schweiger J.,Edelhoff D.. “Digital dentistry: an
          et-Brancot L, Comola G, Dal Carlo L, Moglioni E, Zampetti             overview of recent developments for CAD/CAM generated
          P. The importance of occlusal trauma in the primary etiology          restorations.” Br Dent J 2008 204(9): 505-51.




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