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.

Research progress on the crown-implant ratio and clinical complications / 口腔疾病防治

@#The crown-root ratio (C/R) theory of natural teeth has been widely recognized in the field of stomatology,and has important clinical significance in predicting and assessing the prognosis of natural teeth as well as for abutment selection during denture restoration. In the past few decades, scholars have advocated for the implantation of implants as long in length as possible to improve the success rate according to the theory of crown-root ratio of natural teeth. However, with the application of short implants, our philosophy of implantation has changed, and the relationship between the crown-implant (C/I) ratio and complications has become one of the current research hotspots. In this paper, the concept of the crown-implant ratio, the research progress of the C/I ratio, the implant survival rate and clinical complications of implant restoration were reviewed and summarized, and the following suggestions were put forward: although most studies have shown no significant correlation between the C/I ratio and implant survival or marginal bone loss, this relationship may increase the risk of mechanical complications. A C/I < 3 and a crown length < 15 mm are recommended in implant restoration; when ultra-short implants are applied, the implant system can increase the bone-to-implant contact area, and splint prostheses such as crown or bridge are recommended.

Avaliação das taxas de sucesso e sobrevivência de 497 implantes há cinco anos ou mais em função – estudo retrospectivo com 139 pacientes / Success and survival rates of 497 implants with at least 5 years of function – a retrospective study with 139 patients

Objetivo: avaliar as taxas de sucesso e sobrevivência de implantes há cinco anos ou mais em função. Material e métodos: pacientes tratados com implantes de titânio (Implacil De Bortoli, São Paulo, Brasil) na Fundecto (USP), no período de 1998 a 2008 foram incluídos neste estudo. Os implantes foram classificados individualmente, de acordo com um rigoroso critério de sucesso. Também foram levados em consideração o formato e o tipo de plataforma dos implantes. Resultados: a taxa de sobrevivência dos implantes tipo hexágono externo (n=357) e interno (n=140) foi de 99,4% e 99,3%, respectivamente. Já com relação aos implantes cônicos (n=88) e cilíndricos (n=409), a taxa de sobrevivência foi de 100% e 99,3%, respectivamente. A taxa de sucesso para implantes tipo hexágono externo e interno foi de 90,8% e 93,6%, respectivamente. Implantes cônicos obtiveram 90,9%, enquanto que implantes cilíndricos apresentaram 91,7% de taxa de sucesso. Conclusão: de acordo com o presente estudo, a taxa geral de sobrevivência dos implantes foi de 99,4%, enquanto a taxa de sucesso foi de 91,5%.

Objective: to assess success and survival rates from implants in function for five or more years. Material and methods: patients treated with osseointegrated implants (Implacil De Bortoli, Sao Paulo, Brazil) at Fundecto (USP), from 1998 to 2008, were included in this study. Implants were individually classified using strict success criteria. For further analysis, data were obtained regarding implant’s platform and implant’s macro design. Results: survival rates for external (n=357) and internal hexagon implants (n=140) were 99,4% and 99,3%, respectively. Regarding tapered (n=88) and cylindrical implants (n=409), survival rates were 100% and 99,3%, respectively. Success rates for external and internal hexagon implants were 90,8% and 93,6%. Tapered implants had 90,9% and cylindrical implants presented 91,7% of success rates. Conclusion: according to this retrospective study, the overall survival rate was 99,4% and the overall success rate was 91,5%.

Implant Survival Rates of Maxillary Sinus Augmentation: a Literature Review of Graft Materials

A retrospective study on survival rate of the most posterior single tooth implant / 대한치주과학회지

PURPOSE: The purpose of this study was to assess the long term survival rates of the most posterior single tooth implant and to evaluate the influence of implant characteristics on implant survival. MATERIAL AND METHODS: This retrospective report presents findings on 37 patients with 43 implants replacing single molars. The inclusion criteria were having implants replacing a molar of the most posterior region and follow-up data over at least 6 months. Data were recorded regarding the incidence of complications and survival rates of these implants. RESULTS: The range of follow-up was from 9 to 66 months(mean: 40.2 months). The cumulative survival rate of total implants was 93.0% which reflects the loss of three implants: one had broken neck, one implant failed because of infection, one implant showed failed osseointegration. Abutment- screws loosening occurred in five implants(11.6%). CONCLUSION: Within the limits of this study, a single tooth-implant can serve as a good long-term and predictable treatment modality to replace the most posterior teeth with low complication and failure rates.

Analysis on cause of failure of guided bone regeneration during implant placement: A retrospective study / 대한치주과학회지

PURPOSE: The aim of this retrospective study is to evaluate survival rate of implant and bone formation, to analyze failure contribution factor. MATERIAL AND METHODS: A total of 52 consecutive patients(35 male, 17 female, mean age 49 years) with 104 osseous defects were treated during the period from October 2004 to June 2007 with a simultaneous or staged GBR approach using non-resorbable or resorbable membranes combined with autogenous bone grafts or xenograft(Bio-Oss, Bio-cera, BBP). RESULT: A total of 32(30.8%) of 104 GBR-treated sites failed the bone formation and a total of 5(5.6%) of 89 implants were removed. Early exposure of the membrane has significantly affected bone formation(p<0.05). Non-resorbable membrane showed more exposure of the membrane and low success rate of bone formation than resorbable membrane(p<0.05). There were no difference between success rate of bone formation and using autogenous bone or graft materials. There were no statistically significant difference between success rate of bone formation and smoking or using PRP. Mandible showed more success rate of bone formation than maxilla(p<0.05). CONCLUSION: Early exposure of the membrane, membrane type and maxilla/mandible type have influence on success rate of bone formation during GBR.

A Retrospective study on the survival rate of the sinus perforated implants / 대한치주과학회지

Perforation of maxillary sinus is a common complication of implant placement in posterior maxilla. The purpose of this study was to evaluate the prognosis of sinus perforated implants placed in partially edentulous maxillae. Eighteen sinus perforated implants in 15 patients were examined for cumulative survival rate, radiographic preoperative bone level, and radiographic marginal bone level change. Twenty-two non-perforated implants in the same patients served as control. The results were as follows; 1. There was no statistically significant difference in cumulative survival rate between sinus perforated implants and non-perforated implants (P>0.05). 2. There was no statistically significant difference in the marginal bone level between sinus perforated implants and non-perforated implants (P>0.05). 3. There was no statistically significant difference in cumulative survival rate according to the preoperative bone level (P>0.05). These results suggests that perforation of maxillary sinus may not affect implant success in posterior maxillae.