1,721,053 research outputs found
The complete digital workflow in fixed prosthodontics: a systematic review
Get PDFBackground The continuous development in dental processing ensures new opportunities in the field of fixed prosthodontics in a complete virtual environment without any physical model situations. The aim was to compare fully digitalized workflows to conventional and/or mixed analog-digital workflows for the treatment with tooth-borne or implant-supported fixed reconstructions. Methods A PICO strategy was executed using an electronic (MEDLINE, EMBASE, Google Scholar) plus manual search up to 2016–09-16 focusing on RCTs investigating complete digital workflows in fixed prosthodontics with regard to economics or esthetics or patient-centered outcomes with or without follow-up or survival/success rate analysis as well as complication assessment of at least 1 year under function. The search strategy was assembled from MeSH-Terms and unspecific free-text words: {((“Dental Prosthesis” [MeSH]) OR (“Crowns” [MeSH]) OR (“Dental Prosthesis, Implant-Supported” [MeSH])) OR ((crown) OR (fixed dental prosthesis) OR (fixed reconstruction) OR (dental bridge) OR (implant crown) OR (implant prosthesis) OR (implant restoration) OR (implant reconstruction))} AND {(“Computer-Aided Design” [MeSH]) OR ((digital workflow) OR (digital technology) OR (computerized dentistry) OR (intraoral scan) OR (digital impression) OR (scanbody) OR (virtual design) OR (digital design) OR (cad/cam) OR (rapid prototyping) OR (monolithic) OR (full-contour))} AND {(“Dental Technology” [MeSH) OR ((conventional workflow) OR (lost-wax-technique) OR (porcelain-fused-to-metal) OR (PFM) OR (implant impression) OR (hand-layering) OR (veneering) OR (framework))} AND {((“Study, Feasibility” [MeSH]) OR (“Survival” [MeSH]) OR (“Success” [MeSH]) OR (“Economics” [MeSH]) OR (“Costs, Cost Analysis” [MeSH]) OR (“Esthetics, Dental” [MeSH]) OR (“Patient Satisfaction” [MeSH])) OR ((feasibility) OR (efficiency) OR (patient-centered outcome))}. Assessment of risk of bias in selected studies was done at a ‘trial level’ including random sequence generation, allocation concealment, blinding, completeness of outcome data, selective reporting, and other bias using the Cochrane Collaboration tool. A judgment of risk of bias was assigned if one or more key domains had a high or unclear risk of bias. An official registration of the systematic review was not performed. Results The systematic search identified 67 titles, 32 abstracts thereof were screened, and subsequently, three full-texts included for data extraction. Analysed RCTs were heterogeneous without follow-up. One study demonstrated that fully digitally produced dental crowns revealed the feasibility of the process itself; however, the marginal precision was lower for lithium disilicate (LS2) restorations (113.8 μm) compared to conventional metal-ceramic (92.4 μm) and zirconium dioxide (ZrO2) crowns (68.5 μm) (p < 0.05). Another study showed that leucite-reinforced glass ceramic crowns were esthetically favoured by the patients (8/2 crowns) and clinicians (7/3 crowns) (p < 0.05). The third study investigated implant crowns. The complete digital workflow was more than twofold faster (75.3 min) in comparison to the mixed analog-digital workflow (156.6 min) (p < 0.05). No RCTs could be found investigating multi-unit fixed dental prostheses (FDP). Conclusions The number of RCTs testing complete digital workflows in fixed prosthodontics is low. Scientifically proven recommendations for clinical routine cannot be given at this time. Research with high-quality trials seems to be slower than the industrial progress of available digital applications. Future research with well-designed RCTs including follow-up observation is compellingly necessary in the field of complete digital processing
The Functional Implant Prosthodontic Score (FIPS): assessment of reproducibility and observer variability
Get PDFAbstract
OBJECTIVES:
The aim of this study was to validate the reproducibility and observer variability of the Functional Implant Prosthodontic Score (FIPS), while considering the level of dental experience for intra- and inter-examiner analysis.
MATERIALS AND METHODS:
A total of 44 examiners (n = 31 undergraduate dental students and n = 13 postgraduate prosthodontic students) applied FIPS to ten sample cases each showing one implant-supported single crown for premolar or molar replacements. Examiners' assessments were carried out twice at an interval of 2 weeks (round A and round B). Pearson's correlations including 95% confidence intervals (CI95) were calculated for intra- and inter-examiner reproducibility testing. Cohen's Kappa score was additionally used to analyze the homogeneity of each FIPS variable.
RESULTS:
The mean values of the total FIPS scores for round A (7.21 ± 0.91) and round B (7.27 ± 0.86) showed a strong correlation of 0.9374 (CI95 0.9250; 0.9478). No significant difference was identified between undergraduates and postgraduates representing different levels of dental experience. Homogeneity analysis of the defined FIPS variables was not significantly different.
CONCLUSIONS:
Both intra- and inter-examiner analysis revealed very congruent results for reproducibility testing of FIPS. The findings validated the potential of FIPS as an objective and reliable evaluation instrument in assessing fixed implant restorations in posterior sites independent of the level of dental experience.
CLINICAL RELEVANCE:
FIPS can be considered as an additional diagnostic tool to classify fixed implant restorations in routine dental practice, to compare follow-up observations, and to identify potential risks of failure
Case-specific finite elements analysis of CAD/CAM prostheses to identify design flaws prior to manufacture
No full textPurpose: To apply a design optimization strategy to dental prostheses machining to verify whether this approach can detect flaws occurring in the CAD process and to estimate the influence of the type of material on the occurrence of fractures in restorations. Methods: The stereo lithography interface format of a 4-unit (from canine to first molar) fixed dental prosthesis designed by a conventional dental CAD process was converted into a Finite Element Analysis (FEA) model. This basic model was coupled to the mechanical properties of feldspathic ceramic, lithium disilicate ceramic (LS2) and zirconia (ZrO2) to create three FEA models with different mechanical properties. The models were constrained along the abutment housing surfaces of the canine and the first molar, respectively. Finally, a simulated load of 50 N was applied vertically to the occlusal surface of the first premolar. Results: The FEA showed a stress peak concentration between the second connectors and the second premolar. The stress peak overcame the ultimate tensile stresses of feldspathic and lithium disilicate ceramics; conversely, the ultimate tensile stress of zirconia was not overcome. A geometrical flaw was identified in the 4-unit fixed dental prosthesis. The flaw was sensitive to tensional stress and could lead to failure of the component
A pilot trial on lithium disilicate partial crowns using a novel prosthodontic functional index for teeth (FIT)
Get PDFBACKGROUND: Lithium disilicate is now a well accepted material for indirect restorations. The aim of this trial was to evaluate two lithium disilicate systems using a novel prosthodontic Functional Index for Teeth (FIT). METHODS: Partial adhesive crowns on natural abutment posterior teeth were made on sixty patients. Patients were divided into two groups: Group 1 IPS e.max press (Ivoclar-Vivadent, Schaan, Liecthestein), and Group 2 Initial LiSi press (GC Co., Tokyo, Japan). The restorations were followed-up for 3 years, and the FIT evaluation was performed at last recall. The FIT is composed of seven variables (Interproximal, Occlusion, Design, Mucosa, Bone, Biology and Margins), each of them are evaluated using a 0-1-2 scoring scheme, and is investigated by an oral radiograph and occlusal and buccal pictures. More in details, three variables have the three scores made on the presence or not of major, minor or no discrepancy (for 'Interproximal', 'Occlusion' and 'Design'), presence or not of keratinized and attached gingiva ('Mucosa'), presence of bone loss > 1.5 mm, < 1.5 mm or not detectable ('Bone'), presence or not of Bleeding on Probing and or Plaque Index ('Biology'), presence of detectable gap and marginal stain or not ('Margins'). The Mann-Whitney 'U' test was used and the level of significance was set at p < 0.05. Also, "success" of the crowns (restoration in place without any biological or technical complication) and "survival" (restoration still in place with biological or technical complication) were evaluated. RESULTS: Regarding FIT scores, all partial crowns showed a stable level of the alveolar crest without detectable signs of bone loss in the radiographic analysis. All other evaluated parameters showed a high score, between 1.73 and 2. No statistically significant difference emerged between the two groups in any of the assessed variables (p > 0.05). All FIT scores were compatible with the outcome of clinical success and no one restoration was replaced or repaired and the success rate was 100%. CONCLUSIONS: The results showed that it is possible to evaluate the clinical performance of partial crowns using FIT. The FIT proved to be an effective tool to monitor the performance of the restorations and their compatibility with periodontal tissues at the recall. The FIT can be really helpful for a standardized evaluation of the quality of the therapy in prosthodontic dentistry. The two lithium disilicate materials showed similar results after 3 years of clinical service. TRIAL REGISTRATION: The study protocol was approved by the Ethical Committee of University of Siena (clinicaltrial.gov # NCT01835821), 'retrospectively registered'
Time-dependent supraimplant mucosa changes: short communication
Get PDFPURPOSE
The aim of this short communication was to analyze time-dependent changes of the supraimplant mucosa architecture in the esthetic zone.
MATERIALS AND METHODS
Five patients underwent single-tooth replacement with implant crowns in the anterior maxilla. The supraimplant soft tissue was conditioned with fixed provisional crowns. Quadrantlike digital impressions were taken with an intraoral optical scanning device at three time points: t0, immediately after removal of the provisional (baseline); t1, after 5 minutes; and t2, after 10 minutes. To analyze time-dependent mucosal changes, the corresponding digital files were superimposed for each patient, and baseline (t0) scans were compared with t1 and t2 scans, respectively. Wilcoxon rank sum tests were used for statistical calculations with a strict level of significance at P < .01.
RESULTS
Mean values for supraimplant soft tissue changes were statistically significantly different after 5 minutes (5.5%; standard deviation ± 0.3%) in comparison to the results after 10 minutes (21.7%; standard deviation ± 1.8%). The direction of mucosa shrinkage showed a trend toward palatal sites.
CONCLUSION
Based on the findings of this analysis, changes in supraimplant mucosa architecture seem to be affected only slightly during the first 5 minutes after removal of soft tissue support
Combined Tooth-Implant-Supported Telescopic Prostheses in a Midterm Follow-up of > 2 Years
Get PDFPurpose: The aim of this trial was to evaluate telescopic-retained prostheses on teeth and implants. Materials and Methods: Ten patients with a mean of 2.8 teeth received strategic implants to achieve triangular/quadrangular support. Survival and complication rates were estimated for telescopic abutments and prostheses. Results: After a mean observation period of > 2 years, no abutment was lost and all prostheses were in function. Complication rates were low, and maintenance services were limited to minor interventions. Conclusions: Combined tooth-implant-retained telescopic prostheses improve prosthetic support and offer successful function over a midterm period in patients with a severely reduced dentition
Management of a complication with a fractured zirconia implant abutment in the esthetic zone
Get PDFTechnical complications in implant prosthetic cases represent a major challenge in dentistry. This case report describes minimally invasive management to recover an implant with a fractured remnant of a zirconia abutment, including provisional rehabilitation during a sequential treatment protocol in the esthetic zone. A patient was treated with a screw-retained one-piece implant-supported reconstruction made of a customized zirconia abutment with direct ceramic veneering in the maxillary right central incisor position. During the prosthetic try-in, a fracture in the apical portion of the abutment was evident. The first rescue attempt led to fracture of the retrieval instrument. Immediately, an individualized wired construction was applied to bond the existing fractured reconstruction to the neighboring teeth to maintain the peri-implant mucosal architecture. Because the implant screw canal was blocked, a customized round bur had to be manufactured and was placed in the implant axis with a specific bracket tool from the service set to protect the interior implant threads. Then, the drills of the service set were guided by the newly created access to remove the fractured remnants. The implant screw was retapped and the area rinsed with chlorhexidine solution. All remnants were removed without the need for surgical intervention. Neither the implant connection nor the bone-to-implant interface was damaged. The stepwise treatment approach with the customized round bur combined with the system-specific drills of the service set saved the blocked implant so that the patient could be successfully rehabilitated with a new implant reconstruction
Patient-centered outcomes comparing digital and conventional implant impression procedures: a randomized crossover trial.
No full textOBJECTIVES
The aim of this randomized controlled trial was to compare patient-centered outcomes during digital and conventional implant impressions.
MATERIAL AND METHODS
In a crossover study design, intraoral scanning (IOS) [test] as well as classical polyether impressions [control] were both performed on 20 patients for single-tooth replacement with implant-supported crowns. The sequential distribution of either starting with the test or the control procedure was randomly selected. Patients' perception and satisfaction on the level of convenience-related factors were assessed with visual analogue scale (VAS) questionnaires. In addition, clinical work time was separately recorded for test and control procedures. Statistical analyses were performed with Wilcoxon signed-rank tests and corrected for multiple testing by the method of Holm.
RESULTS
On VAS ranging from 0 to 100, patients scored a mean convenience level of 78.6 (SD ± 14.0) in favor of IOS compared to conventional impressions with 53.6 (SD ± 15.4) [P = 0.0001]. All included patients would prefer the digital workflow if in the future they could choose between the two techniques. Secondary, IOS was significantly faster with 14.8 min (SD ± 2.2) compared to the conventional approach with 17.9 min (SD ± 1.1) [P = 0.0001].
CONCLUSION
Based on the findings of this investigation, both impression protocols worked successfully for all study participants capturing the 3D implant positions. However, the digital technique emerges as the most preferred one according to patient-centered outcomes and was more time-effective compared to conventional impressions
Complete digital workflow for the production of implant-supported single-unit monolithic crowns.
No full textOBJECTIVES
The aim of this case series was to introduce a complete digital workflow for the production of monolithic implant crowns.
MATERIAL AND METHODS
Six patients were treated with implant-supported crowns made of resin nano ceramic (RNC). Starting with an intraoral optical scan (IOS), and following a CAD/CAM process, the monolithic crowns were bonded either to a novel prefabricated titanium abutment base (group A) or to a CAD/CAM-generated individualized titanium abutment (group B) in premolar or molar sites on a soft tissue level dental implant. Economic analyses included clinical and laboratory steps. An esthetic evaluation was performed to compare the two abutment-crown combinations.
RESULTS
None of the digitally constructed RNC crowns required any clinical adaptation. Overall mean work time calculations revealed obvious differences for group A (65.3 min) compared with group B (86.5 min). Esthetic analysis demonstrated a more favorable outcome for the prefabricated bonding bases.
CONCLUSIONS
Prefabricated or individualized abutments on monolithic RNC crowns using CAD/CAM technology in a model-free workflow seem to provide a feasible and streamlined treatment approach for single-edentulous space rehabilitation in the posterior region. However, RNC as full-contour material has to be considered experimental, and further large-scale clinical investigations with long-term follow-up observation are necessary
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