A digital workflow for computer-guided implant surgery integrating CBCT, model scanning, and CAD/CAM for a complete edentulism implant-supported prosthesis: a technique procedure.

The utilization of digital 3D surface images (STL format) for planning cases of computer-guided implant surgery is very useful in partially edentulous cases. In fully edentulous cases, however, the absence of teeth makes it necessary to add reference markers. The proposed protocol demonstrates a simple procedure that allows for the superimposition of STL and radiologic data (DICOM format). In the presented patient case, the tissue-bearing area of the prosthesis was relined with a polysulfide impression material and sent to the laboratory. A master cast was produced. The prosthesis was relined to improve intraoral stability and was provided with at least three radiopaque 3D markers. An STL copy of the prosthesis and the model was generated through a laboratory scanner. The patient wore the prosthesis with the attached markers during the 3D radiologic examination. In the planning software (CoDiagnostiX; Dental Wings), the prosthesis markers on the STL were matched to the corresponding markers visible on the DICOM data. Then, the STL of the model was matched to that of the prosthesis. Once the STL of the mucosa and the prosthesis were imported into the software, new possibilities arose, ie, the option to add other digital or traditional tooth setups to the same radiologic data or to design a surgical guide based on the actual mucosa of the patient.

Severe Case of Osteonecrosis Following Implant Placement in a Patient in Therapy With Bisphosphonates: A Case Report.

Osteonecrosis of the jaw is a rare complication that has been associated with the use of bisphosphonates. A 77-year-old patient presented in April 2013 asking for a consultation. She reported that in May 2009, she underwent an implant rehabilitation with 8 implants and an immediately loaded fixed prosthesis in the maxilla. After a few months the patient started to report pain and purulent secretions that were neglected by the clinician for several years. She decided to refer to the Dental Clinic after another acute pain episode. Once the fixed prosthesis was removed, exposed necrotic bone was found in relation to the implants. The patient reported having taken oral alendronic acid to treat osteoporosis since before 2006. The patient underwent a functional endoscopic sinus surgery and a removal of necrotic bone blocks. Three years of follow-up showed healed tissues with no recurrence, although the alveolar crest appeared irregular on radiographs.

Implant supported cantilevered fixed dental rehabilitations in partially edentulous patients: Systematic review of the literature. Part I.

OBJECTIVES: To investigate in which clinical situations a cantilever fixed implant supported restorations can be a treatment alternative and which complications are reported. MATERIALS AND METHODS: Two operators screened the literature (MEDLINE, EMBASE) and performed a hand search on the main journals dealing with implantology and prosthetics until 31 December 2017. Only articles that considered cantilever implant fixed restorations with at least 10 patients and with a mean follow-up of at least 5 year were selected. The outcome variables were survival of implants and prosthesis, mechanical, technical and biological complications, marginal bone loss. The review was performed according to the PRISMA statements. Risk of bias assessment was evaluated. Failure and complication rates were analysed using random effect Poisson regression models to obtain summary estimate of 5- and 10-year survival and complication rates. RESULTS: A total of nine papers were selected for partially edentulous patients and reported high survival rate of the prosthesis. The estimated survival rate for 5-10 years was calculated to be 98.4% for the implants and 99.2% for the rehabilitations. Mechanical, technical and biological complications were reported with a cumulative 5-10 years complication rate of 28.66% and 26.57% for the patients and for the prosthesis, respectively. Two papers for single implant supporting 2-unit cantilever were not sufficient to draw conclusions. CONCLUSIONS: There is evidence that cantilever can be successful treatment in partially edentulous patients. In two adjacent edentulous sites, data are not yet sufficient.

Implant-supported cantilevered fixed dental rehabilitations in fully edentulous patients: Systematic review of the literature. Part II.

AIM: To investigate fully edentulous patients rehabilitated with cantilever-fixed implant-supported restorations and to analyse which complications are reported for this type of treatment. MATERIALS AND METHODS: Two operators screened the literature (MEDLINE, EMBASE) and performed a hand search on the main journals dealing with implantology and prosthetics until 31 December 2017. Only articles that considered cantilever implant-fixed restorations with at least 10 patients and with a mean follow-up of at least 5 years were selected. The outcome variables were survival of implants and prosthesis, mechanical, technical and biological complications, marginal bone loss. The review was performed according to the PRISMA statements. The risk of bias was evaluated for each article. Failure and complication rates were analysed using random effect Poisson regression models to obtain summary estimate of 5- and 10-year survival and complication rates. RESULTS: Fourteen papers for fully edentulous patients were selected. The estimated 5 to 10 years survival rate was calculated to be 99.00% and 96.7% for the implants and the prosthesis, respectively. A total of 299 complications (technical and biological) were reported with a cumulative 5-10 years complication rate of 44.41% and 39.46% for the patients and for the prosthesis, respectively. CONCLUSIONS: There is evidence that cantilever can be successful treatment in fully edentulous patients.

Stratification of prosthetic complications by manufacturer in implant-supported restorations with a 5 years' follow-up: systematic review of the literature.

INTRODUCTION: Prosthetic complications on implant-supported restorations have been documented in several papers published in the literature. Several manufacturers are present on the market but results are often cumulated and may thus be misleading. The objective of the present review is to assess the prosthetic complications of implant-supported restorations with particular interest of the results obtained with prostheses from different manufacturers. EVIDENCE ACQUISITION: A manual search of Medline/PubMed was carried out up to June 2016, yielding a total of 6832 articles, which were narrowed down to 1450, then 347 abstracts to include 55 papers after full text reading. Papers with at least 5 years of follow-up reporting on prosthetic complications of single and fixed partial prosthesis were included. Prosthetic complications were divided into mechanical and technical complications, and reported in a table. EVIDENCE SYNTHESIS: Overall 14.4% of prosthetic complication was found for a total of 6623 restorations followed for an average of 7.4 years (range 5-16 years). Results where then sorted and compared. Single crowns were affected by 1.4% of mechanical complications and 10.9% of technical complications after a mean of 7.4 years. Fixed partial prosthesis were affected by 2.5% of mechanical complications and 18% of technical complications. Screw-retained and cemented restorations were calculated to have a 5 years rate of complications of 21.2% and 9.3%, respectively, which demonstrated a statistically difference with fisher exact test with P<0.1. Only 3 manufacturers presented more than 10 articles and were directly compared with Fisher's exact test with P<0.1. The incidence of overall complications was estimated to be after 5 years of 11.2%, 10.8% and 13.8% for Straumann, Nobel, and Astratech, respectively, but dividing results in mechanical and technical complications, gave different results. Straumann was estimated to have less mechanical complications after 5 years in respect to Nobel and Astratech, but the three were similar for technical complications. CONCLUSIONS: although studies present very different material and methods and do not report all data, some conclusions can be made. The difference between mechanical complications lead the authors to suppose that there might be a difference in results obtained by different implant abutment connections. It is also noticed that all papers were published by expert clinicians and universities research centers that apply rigid surgical and prosthetic protocols and use original abutments.