Screw retained vs. cement retained implant‐supported fixed dental prosthesis

A fixed dental prosthesis can be secured to an endosseous implant via cementation (using a provisional or definitive cement) on an implant abutment that is screw retained to the implant or directly in the implant via screw retention. The clinical decision as to which retention system best suits the individual patient depends on several factors. The aim of this review is to present a detailed overview of the factors potentially influencing whether to choose screw retention or cement retention. These factors include the individual indication, advantages and disadvantages of the different retention mechanisms, the retention provided, retrievability, provisionalization, esthetics and clinical performance, including failures and complications. The results of recently published systematic reviews on this topic are discussed and an overview is provided. A decision tree is presented to facilitate the clinical selection of the retention type. This overview concludes that the choice of retention type (screw retained or cement retained) might not influence the overall survival of the implant‐supported fixed dental prosthesis, but may be responsible for the development of certain complications. The decision may depend on technical feasibility and on weighing the pros and cons.     

Retention forces between primary and secondary CAD/CAM manufactured telescopic crowns: an in vitro comparison of common material combinations

Clinical Oral Investigations - To analyze the retention forces between primary and secondary telescopic crowns milled from various materials and to compare them with the retention forces between...     

Long‐Term Stability of Contour Augmentation With Early Implant Placement Following Single Tooth Extraction in the Esthetic Zone: A Prospective,Cross‐Sectional Study in 41 Patients With a 5‐ to 9‐Year Follow‐Up

Background: Early implant placement with simultaneous contour augmentation is documented with short‐ and medium‐term studies. The long‐term stability of contour augmentation is uncertain. Methods: In this prospective, cross‐sectional study, 41 patients with an implant‐borne single crown were examined twice, in 2006 and 2010. Clinical, radiologic, and esthetic parameters were assessed at both examinations. In addition, a cone beam computed tomographic (CBCT) image was obtained during the second examination to assess the dimensions of the facial bone wall. Results: All 41 implants demonstrated ankylotic stability without signs of peri‐implant infection at both examinations. The clinical parameters remained stable over time. Satisfactory esthetic outcomes were noted, as assessed by the pink and white esthetic score (PES/WES) indices. Overall, the PES scores were slightly higher than the WES scores. None of the implants developed mucosal recession over time, as confirmed by values of the distance between implant shoulder and mucosal margin and cast measurements. The periapical radiographs yielded stable peri‐implant bone levels, with a mean distance between implant shoulder and first visible bone‐implant contact value of 2.18 mm. The CBCT analysis demonstrated a mean thickness of the facial bone wall ≈2.2 mm. In two implants (4.9%) no facial bone wall was detectable radiographically. Conclusions: This prospective cross‐sectional study demonstrates stable peri‐implant hard and soft tissues for all 41 implants examined and satisfactory esthetic outcomes overall. The follow‐up of 5 to 9 years confirmed again that the risk for mucosal recession is low with early implant placement. In addition, contour augmentation with guided bone regeneration was able to establish and maintain a facial bone wall in 95% of patients.     

Stability of Contour Augmentation and Esthetic Outcomes of Implant‐Supported Single Crowns in the Esthetic Zone: 3‐Year Results of a Prospective Study With Early Implant Placement Postextraction

Background: Early implant placement is one of the treatment options after tooth extraction. Implant surgery is performed after a healing period of 4 to 8 weeks and combined with a simultaneous contour augmentation using the guided bone regeneration technique to rebuild stable esthetic facial hard‐ and soft‐tissue contours. Methods: In this prospective study, 20 patients were treated with an implant‐born single crown and followed for 3 years. Clinical, radiologic, and esthetic parameters were recorded to assess treatment outcomes. Results: At the 3‐year examination, all 20 implants were successfully integrated, demonstrating ankylotic stability and healthy peri‐implant soft tissues as documented by standard clinical parameters. Esthetic outcomes were assessed by the pink esthetic score (PES) and white esthetic score (WES) and confirmed pleasing results overall. WES values were slightly superior to PES values. Periapical radiographs showed minimal crestal bone loss around used bone‐level implants with a mean bone loss of 0.18 mm at 3 years. Only two implants revealed bone loss between 0.5 and 1.0 mm. One of these implants had minor mucosal recession <1.0 mm. Conclusions: This prospective study evaluates the concept of early implant placement and demonstrated successful tissue integration for all 20 implants and stable bone‐crest levels around implant–abutment interfaces according to the platform‐switching concept. The midterm 3‐year follow‐up revealed pleasing esthetic outcomes and stable facial soft tissues. The risk of mucosal recession was low, with only one patient showing minor recession of the facial mucosa. These encouraging results need to be confirmed with a 5‐year follow‐up examination.     

A Systematic Review of the Clinical Performance of Tooth‐Retained and Implant‐Retained Double Crown Prostheses with a Follow‐Up of ≥3 Years

Purpose: The objective of this review was to systematically screen the literature for data related to the survival and complication rates observed with dental or implant double crown abutments and removable prostheses under functional loading for at least 3 years. Materials and Methods: A systematic review of the dental literature from January 1966 to December 2009 was performed in electronic databases (PubMed and Embase) as well as by an extensive hand search to investigate the clinical outcomes of double crown reconstructions. Results: From the total of 2412 titles retrieved from the search, 65 were selected for full‐text review. Subsequently, 17 papers were included for data extraction. An estimation of the cumulative survival and complication rates was not feasible due to the lack of detailed information. Tooth survival rates for telescopic abutment teeth ranged from 82.5% to 96.5% after an observation period of 3.4 to 6 years, and for tooth‐supported double crown retained dentures from 66.7% to 98.6% after an observation period of 6 to 10 years. The survival rates of implants were between 97.9% and 100% and for telescopic‐retained removable dental prostheses with two mandibular implants, 100% after 3.0 and 10.4 years. The major biological complications affecting the tooth abutments were gingival inflammation, periodontal disease, and caries. The most frequent technical complications were loss of cementation and loss of facings. Conclusions: The main findings of this review are: (I) double crown tooth abutments and dentures demonstrated a wide range of survival rates. (II) Implant‐supported mandibular overdentures demonstrated a favorable long‐term prognosis. (III) A greater need for prosthetic maintenance is required for both tooth‐supported and implant‐supported reconstructions. (IV) Future areas of research would involve designing appropriate longitudinal studies for comparisons of survival and complication rates of different reconstruction designs.