Replacement of maxillary lateral incisors with digitally manufactured single tooth retained all-ceramic pontics: a clinical report / Reabilitação da região de incisivo lateral superior ausente por pôntico modelo cantiléver em cerâmica pura fabricado digitalmente: relato de caso clínico

Several treatment options for replacement of anterior missing teeth exist, varying from no-prep (no preparation) adhesive restorations to implants. Patients' biological, psychological, economic conditions or age have an effect on the treatment choice. It is important to perform the most conservative and beneficial treatment option considering the patient based factors. The aim of this case report was to demonstrate a single session, minimally invasive, cantilevered 2-unit all-ceramic restorations replacing anterior missing teeth combined with the advantages of CAD/CAM technology and materials. (AU)

Existem várias opções de tratamento para reabilitação de dentes anteriores ausentes, variando de restaurações adesivas sem preparo (sem preparação) até implantes. As condições biológicas, psicológicas, econômicas ou a idade dos pacientes têm um efeito na escolha do tratamento. É importante realizar a opção de tratamento mais conservadora e benéfica, considerando os fatores baseados no paciente. O objetivo deste relato de caso foi demonstrar em sessão única, minimamente invasiva, um cantiléver de restaurações de cerâmica pura de 2 unidades, reabilitando a região de dentes anteriores ausentes combinadas com as vantagens da tecnologia CAD/CAM.(AU)

Clinical observation of cement-retained and screw-retained implant-supported denture in edentulous patients / 口腔疾病防治

Objective@# To evaluate the clinical effects of full-arch cement-retained implant-supported combined crowns and screw-retained implant-supported bridge dentures in complete or half edentulous patients. @*Methods @#A total of 25 patients with complete or partial edentulous dentures followed up for 1, 3, and 5 years in our hospital from June 2013 to June 2018 and were treated with Straumann bone horizontal implantation, cobalt-chromium stenting and cobalt-chromium porcelain restoration with cement-retained and screw-retained implant-supported fixed dental prostheses to evaluate the accumulative implant survival rate, accumulative prosthesis survival rate, mechanical complications, and biological complications in both groups. @*Results @#There were 25 complete or half edentulous patients who received 165 Straumann implants and 28 implant-supported fixed dental prostheses in this study. There were 11 cases with 69 implants in the cement group and 17 cases with 96 implants in the screw group. The accumulative implant survival rate was 100% in the cement group and 96.9% in the screw group. The accumulative prosthesis survival rate was 100% in both groups. The cumulative peri-implant mucositis rate was 23.2% in the cement group and 29.2% in the screw group, and the peri-implantitis rate was 6.8% in the cement group and 7.3% in the screw group. There was 1 case of porcelain collapse (n=1/11) and no screw of abutment loosening in the cement group and 4 cases of porcelain collapse (n=4/17) and 1 case of screw loosening in the screw group. No fracture of abutment was observed in either group. There was no difference in bone loss between the two groups in the first year (P > 0.05), and a higher rate of bone loss was found in the screw group in the third and fifth years (P < 0.05). There was no difference in the sulcus bleeding index(mSBI) between the two groups in the first year and the third year (P > 0.05) and a higher modified mSBI value in the cement group in the fifth year (P < 0.05).@*Conclusion @#The survival rates of the implant and prosthesis for cement-retained or screw-retained implant-supported fixed dental prostheses were both high, but there were more mechanical and biological complications in the traditional cobalt-chromium alloy screw-retainer group. The removal of residual adhesives must be reasonably considered when choosing the cement retention method.

Radiographic examination of fixed dental prostheses based on dental implants: Systematic and meta-analysis / 国际药学研究杂志

Background and aim: The aim of this systematic and meta-analysis was Radiographic Examination of fixed dental prostheses Based on Dental Implants. Methods: The search took place between 2015 and 2019. Database search was conducted using MEDLINE, PubMed, Cochrane Library, Embase, ISI, google scholar. In this study, we first reviewed the abstract of the articles and selected the studies that had the most coordination with our goals, and then we examined the entire text and finally, four studies were selected. Results: In this systematic review and meta-analysis, 137 patients were evaluated in this study. The mean age was 58.66. Just in one study, follow-up was 6-12 month was 60 and in two studies 36 month. No significant in all studies. Survival rate in three was 100%, just in one study was 98.7%. Conclusions: This systematic review and meta-analysis showed positive radiographic outcomes of fixed dental prostheses Based on Dental Implants.

In vitro study of the fracture resistance of monolithic lithium disilicate, monolithic zirconia, and lithium disilicate pressed on zirconia for three-unit fixed dental prostheses

PURPOSE: The purpose of this study was to determine fracture resistance and failure modes of three-unit fixed dental prostheses (FDPs) made of lithium disilicate pressed on zirconia (LZ), monolithic lithium disilicate (ML), and monolithic zirconia (MZ). MATERIALS AND METHODS: Co-Cr alloy three-unit metal FDPs model with maxillary first premolar and first molar abutments was fabricated. Three different FDPs groups, LZ, ML, and MZ, were prepared (n = 5 per group). The three-unit FDPs designs were identical for all specimens and cemented with resin cement on the prepared metal model. The region of pontic in FDPs was given 50,000 times of cyclic preloading at 2 Hz via dental chewing simulator and received a static load until fracture with universal testing machine fixed at 10°. The fracture resistance and mode of failure were recorded. Statistical analyses were performed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni's correction (α=0.05/3=0.017). RESULTS: A significant difference in fracture resistance was found between LZ (4943.87 ± 1243.70 N) and ML (2872.61 ± 658.78 N) groups, as well as between ML and MZ (4948.02 ± 974.51 N) groups (P.05). With regard to fracture pattern, there were three cases of veneer chipping and two interfacial fractures in LZ group, and complete fracture was observed in all the specimens of ML and MZ groups. CONCLUSION: Compared to monolithic lithium disilicate FDPs, monolithic zirconia FDPs and lithium disilicate glass ceramics pressed on zirconia-based FDPs showed superior fracture resistance while they manifested comparable fracture resistances.

Evaluation of the effect of zirconia all-ceramic fixed dental prostheses designed and manufactured by CAD/CAM in restoration of posterior teeth / 实用口腔医学杂志

To observe the 36 months follow-up outcome of zirconia all-ceramic posterior fixed dental prostheses(FDPs)designed and manu-factured by computer aided design and computer aided manufacture (CAD /CAM)from clinical aspect,and to evaluate the success rate of zirconia framework and veneering porcelain.78 patients with less than three teeth lost which had natural opposing teeth were included.A to-tal of ninty-two zirconia all-ceramic FDPs (59 three-unit FDPs,20 four-unit FDPs and 13 five-unit FDPs)were made by CAD /CAM.Three years after cementation of the restorations,the reasons for complication and failure of FDPs in different lengths were analysed.Six FDPs were removed (frame fracture:1;porcelain fracture:1;secondary caries:2;vertical root fractures and post-core fracture after root canal therapy of premolars:2).The success rate of these FDPs was 93.5%.The success rate of zirconia all-ceramic crowns and bridges was higher.Their clinical effect was satisfactory.The main complications of these FDPs were porcelain fracture and de-bonding.

A root submergence technique for pontic site development in fixed dental prostheses in the maxillary anterior esthetic zone

PURPOSE: This case report discusses the effect of a root submergence technique on preserving the periodontal tissue at the pontic site of fixed dental prostheses in the maxillary anterior aesthetic zone. METHODS: Teeth with less than ideal structural support for fixed retainer abutments were decoronated at the crestal bone level. After soft tissue closure, the final fixed dental prostheses were placed with the pontics over the submerged root area. Radiographic and clinical observations at the pontic sites were documented. RESULTS: The submerged roots at the pontic sites preserved the surrounding periodontium without any periapical pathology. The gingival contour at the pontic site was maintained in harmony with those of the adjacent teeth, as well as the overall form of the arch. CONCLUSIONS: The results of this clinical report indicate that a root submergence technique can be successfully applied in pontic site development with fixed dental prostheses, especially in the maxillary anterior esthetic zone.

Modified measuring compass as an intraoral paralleling device.

This article describes a simple technique of useful modification of measuring compass, procured from a school compass box, to make an intraoral paralleling device. This device is useful in examining parallelism of tooth or implant abutment preparations for a common path of placement in fixed dental prostheses. It can be used to examine the parallelism of guiding planes in removable partial denture patients as well.