From porcelain-fused-to-metal to zirconia: clinical and experimental considerations.

The goal of the current publication is to provide a comprehensive literature review on the topic of dental implant materials. The following paper focuses on conventional titanium implants and more recently introduced and increasingly popular zirconia implants. Major subtopics include the material science and the clinical considerations involving both implant materials and the influence of their physical properties on the treatment outcome. Titanium remains the gold standard for the fabrication of oral implants, even though sensitivity does occur, though its clinical relevance is not yet clear. Zirconia implants may prove to be promising in the future; however, further in vitro and well-designed in vivo clinical studies are needed before such a recommendation can be made. Special considerations and technical experience are needed when dealing with zirconia implants to minimize the incidence of mechanical failure.

https://pure.uva.nl/ws/files/2531883/164424_484372.pdf

A Critical Review of Dental Implant Materials with an Emphasis on Titanium versus Zirconia

https://www.journalofprosthodonticresearch.com/article/S1883-1958(16)00009-8/pdf

Advancements in CAD/CAM technology: Options for practical implementation

Ceramic dental biomaterials and CAD/CAM technology: state of the art.

3D Printed Versus Conventionally Cured Provisional Crown and Bridge Dental Materials

Statement of problem Improving dental esthetics is a main objective of prosthodontic treatment. Recently, digital diagnostic waxing has been proposed as an alternative to conventional diagnostic waxing; however, the impact on esthetics has not been evaluated. Purpose The purpose of this study was to evaluate the impact of diagnostic waxing on biometric esthetic variables and to compare the esthetic outcome achieved by digital waxing with conventional waxing. Material and methods Three biometric variables were evaluated: perceived frontal proportion (PFP), width/height (W:H) ratio, and symmetry. Maxillary casts of 13 patients were collected. All of them had maxillary anterior teeth that required prosthodontic treatment. Two forms of diagnostic waxing were executed: conventional and digital waxing. Measurements of the esthetic variables were conducted digitally. For the PFP, a frontal image was made and the width of each tooth was measured. Subsequently, the PFP values of the lateral incisor to central incisor and of the canine to central incisor were calculated. In addition, the height and width of each tooth was measured to calculate the W:H ratio. Using the previous measurements, the symmetry between the right and left sides was determined. Results No consistent or recurrent PFP was detected for any cast. The diagnostic waxing did not alter the PFP of the pretreatment casts. The diagnostic waxing had restored the W:H ratio to what is assumed to be a natural ratio. An improvement in symmetry was detected after the diagnostic waxing and was more prominent after the digital waxing. However, no significant difference was found between the 2 diagnostic waxing methods. Conclusions The 2 diagnostic waxing methods influenced the esthetic variables of the anterior maxillary teeth and yielded similar outcomes. Digital waxing appears to be a reasonable alternative, but further investigations are needed to ensure its practicality.

Impact of digital prosthodontic planning on dental esthetics: Biometric analysis of esthetic parameters.

Purpose: To compare the Encode impression protocol (Biomet 3i) with the conventional impression protocol in terms of treatment duration, clinical accuracy, and outcome up to the first postplacement review of singleimplant crowns. 
Materials and Methods: A total of 45 implants were included in this study. The implants were randomly allocated to the Encode group (23 implants) or the conventional group (22 implants). At the time of surgery, all implants received two-piece Encode healing abutments. The implants were restored 3 months after insertion. In the conventional protocol, open-tray implant-level impressions were taken and the implants were restored with prefabricated abutments and porcelain-fused-to-metal (PFM) crowns. For the implants in the Encode group, closed-tray impressions of the healing abutments were taken. The generated casts were sent to the Biomet 3i scanning/milling center for custom abutment manufacturing on which PFM crowns were fabricated. Treatment duration (laboratory and clinical), clinical accuracy of occlusal and proximal contacts, and outcome (esthetics, patient satisfaction, and crown contour) were evaluated with the aid of a series of questionnaires. 
Results: The Encode protocol required significantly less laboratory time (18 minutes) than the conventional protocol for adjustment of the abutments. The impression pour time, time for the laboratory to return the crown, time for crown insertion at the final appointment, and total clinical time for crown insertion did not differ significantly between the two protocols. Likewise, clinical accuracy, esthetics, and patient satisfaction were similar for the two protocols. 
Conclusion: The two protocols were clinically comparable. The Encode protocol is advantageous in reducing the laboratory time before crown fabrication.

The Effect of Coded Healing Abutments on Treatment Duration and Clinical Outcome: A Randomized Controlled Clinical Trial Comparing Encode and Conventional Impression Protocols.

Background To ensure accurate implant placement, surgical guides are used to control the steps of implant placement surgery. Purpose Evaluation of the accuracy of implant placement in long span edentulous area by novice implant clinicians according to fully-guided (FG), pilot-guided (PG), and freehand (FH) placement protocols. Materials and methods Maxillary surgical models with four missing teeth from the right first canine to the first molar were produced by 3-dimensional printing. Fourteen clinicians new to implant dentistry participated in the study, and each one of them inserted one canine and one molar implant for every implant placement protocol. All implant placement steps were completed in phantom heads to simulate the clinical situation. To evaluate the accuracy, the implant vertical, horizontal platform, horizontal apex, angle, and interimplant distance deviations from the planned positions were calculated. Results With the exception of vertical deviation, the FG placement was clearly more accurate than the PG and FH placements for all the variables for canine and molar implants. The PG placement was significantly more accurate than the FH placement for the horizontal platform and apex deviations, and interimplant distance deviation. The FG placement did not show a significant impact of the location of the implant, or the horizontal deviations of the platform or the apex. The PG and FH placements showed increased deviation at the canine implant than the molar implant, and at the apex of the implants than the platform of the implants. Conclusions Within the limitations of this in vitro study, novice clinicians achieved a significantly more accurate implant position with FG placement, followed by PG and FH placements respectively. Therefore, a form of guided surgery is beneficial for novice clinicians.

Accuracy of static computer‐assisted implant placement in long span edentulous area by novice implant clinicians: A cross‐sectional in vitro study comparing fully‐guided, pilot‐guided, and freehand implant placement protocols

Objective: The aim of this study was to evaluate the impact of different prosthodontic planning methods on the morphological symmetry of maxillary anterior teeth. Materials and Methods: In 13 patients receiving fixed prosthodontic treatment, dental models were obtained from the Oral Health Centre of Western Australia. Two forms of diagnostic prosthodontic planning were executed: conventional wax-up and digital wax-up. The asymmetry was evaluated at two levels: tooth morphological asymmetry (TMA) and anterior segment morphological asymmetry (ASMA). For the TMA, the labial surface of each anterior tooth was superimposed on a mirror image of the contralateral tooth. The ASMA involved superimposition of the combined labial surface of all the anterior teeth on one side on the mirror image of the combined labial surface of the contralateral side. For each asymmetry, the discrepancies in the form of 3D Euclidean distances were calculated and statistically evaluated by the Kruskal-Wallis test (p = 0.05). Results: At the TMA level, the digital wax-up models had significantly less asymmetry (p 0.05). Conclusion: In this study, the single tooth symmetry had improved after the digital wax-up. However, the conventional wax-up had a minimal impact on single tooth symmetry. ASMA was minimally affected by the two wax-ups.

/pdf/morphological-symmetry-of-maxillary-anterior-teeth-before-31gt8jj3zn.pdf

Morphological Symmetry of Maxillary Anterior Teeth before and after Prosthodontic Planning: Comparison between Conventional and Digital Diagnostic Wax-Ups.

BACKGROUND: Accurate implant impression is an essential requirement for the fabrication of implant prosthesis. This in vitro study evaluated the accuracy of digital impressions by intraoral scanner (IOS) systems in comparison to conventional impressions for recording the position of 2 parallel implants and 2 divergent implants. MATERIALS AND METHODS: In vitro 3-unit prosthesis master models with 2 tissue level implants were fabricated; one model had parallel implants, and the other model had one 15° tilted implant. The conventional open-tray impressions were obtained with non-splinted (NSP) and splinted (SP) impression copings. Trios 4 (TS), Medit i500 (MT), and True Definition (TD) were used to make digital impressions with scan bodies. A total of 10 impressions were obtained with every technique. The virtual test images of the conventional and digital impressions were converted to 2 virtual implant images. For each group, trueness, precision, inter-implant distance deviation, and angle deviation were measured. RESULTS: There was a general tendency for digital impressions to provide a more accurate outcome for trueness, precision, and angle deviation. The 2 conventional impressions showed similar accuracy, except for the angle deviation, where the NSP was significantly inferior than SP (p < 0.01) for the divergent implants model. The TD was generally the least accurate among all the IOS systems, especially for the inter-implant distance deviation (p < 0.05). CONCLUSIONS: Within the limitations of the laboratory set-up of the present study and the limited clinical resemblance, the digital impressions appeared to have sufficient accuracy for 2 implants and were least affected by the presence of angle between implants. The most inferior outcome was observed for the NSP technique.

/pdf/accuracy-of-digital-impressions-versus-conventional-5bjobjobng.pdf

Jaafar Abduo

Papers

Impact of digital prosthodontic planning on dental esthetics: Biometric analysis of esthetic parameters.

The Effect of Coded Healing Abutments on Treatment Duration and Clinical Outcome: A Randomized Controlled Clinical Trial Comparing Encode and Conventional Impression Protocols.

Accuracy of static computer‐assisted implant placement in long span edentulous area by novice implant clinicians: A cross‐sectional in vitro study comparing fully‐guided, pilot‐guided, and freehand implant placement protocols

Morphological Symmetry of Maxillary Anterior Teeth before and after Prosthodontic Planning: Comparison between Conventional and Digital Diagnostic Wax-Ups.

Accuracy of digital impressions versus conventional impressions for 2 implants: an in vitro study evaluating the effect of implant angulation.