Does Oral Implant Design Affect Marginal Bone Loss? Results of a Parallel-Group Randomized Controlled Equivalence Trial.

OBJECTIVE: To test whether or not the modified design of the test implant (intended to increase primary stability) has an equivalent effect on MBL compared to the control. METHODS: Forty patients were randomly assigned to receive test or control implants to be installed in identically dimensioned bony beds. Implants were radiographically monitored at installation, at prosthetic delivery, and after one year. Treatments were considered equivalent if the 90% confidence interval (CI) for the mean difference (MD) in MBL was in between -0.25 and 0.25 mm. Additionally, several soft tissue parameters and patient-reported outcome measures (PROMs) were evaluated. Linear mixed models were fitted for each patient to assess time effects on response variables. RESULTS: Thirty-three patients (21 males, 12 females; 58.2 ± 15.2 years old) with 81 implants (47 test, 34 control) were available for analysis after a mean observation period of 13.9 ± 4.5 months (3 dropouts, 3 missed appointments, and 1 missing file). The adjusted MD in MBL after one year was -0.13 mm (90% CI: -0.46-0.19; test group: -0.49; control group: -0.36; p = 0.507). CONCLUSION: Both implant systems can be considered successful after one year of observation. Concerning MBL in the presented setup, equivalence of the treatments cannot be concluded. REGISTRATION: This trial is registered with the German Clinical Trials Register (ID: DRKS00007877).

A retrospective evaluation of teeth restored with zirconia ceramic posts: 10-year results.

INTRODUCTION: Zirconia posts can be used as an esthetic alternative to metal posts. Despite their advantages, there is a lack of information about the long-term performance of zirconia posts. OBJECTIVES: This retrospective clinical study examined the survival probability, clinical performance, and reasons for failure of teeth restored with zirconia posts after an observation period of up to 10 years. MATERIALS AND METHODS: After a mean observation period of 10 years, clinical and radiographic examinations were carried out for a total of 64 posts in 45 patients. The posts received mainly either ceramic or direct composite buildups. All posts were adhesively cemented, after air abrasion with alumina particles or silica coating and silanization. The majority of the reconstructed teeth were used as abutments for metal ceramic or ceramic fixed dental prostheses. Kaplan-Meier analysis was employed to compute the survival probability of teeth restored with zirconia posts. Cox regression analysis was used to assess the risk of failure and to identify possible covariates. RESULTS: During the follow-up period, a drop-out rate of 49.4 % was recorded. The survival probability for teeth with zirconia posts was 81.3 % after 10 years. CONCLUSION: Within the limits of this study, zirconia posts can be used for abutments that will be restored with ceramic restorations. However, due to the high patient drop-out rate, careful interpretation of the current results is suggested. CLINICAL RELEVANCE: The present paper is the first 10-year clinical study on teeth restored with zirconia posts and could serve as a reference for future research. In addition, it provides long-term data about restorations already implemented by dental practitioners.

Tilted implants to support a maxillary removable dental prosthesis: a case report.

The placement of implants in a tilted position may provide a viable treatment modality, especially for patients with atrophic maxillae. The treatment steps and procedures for a maxillary implant-supported removable dental prosthesis, as well as a mandibular telescopic crown-retained removable dental prosthesis, are described. The concept of tilted implants via 3D planning and flapless surgery is presented. The final outcome facilitated improvement in the patient's satisfaction and comfort, as well as long-term stability of the implants and prosthesis. In addition, there was a reduction in cost by avoiding augmentation procedures.

Implant neck configurations for preservation of marginal bone level: a systematic review.

PURPOSE: The aim of this article was to evaluate the effectiveness of various implant neck configurations in the preservation of marginal bone level as well as to identify the available scientific evidence. MATERIALS AND METHODS: Online and hand searches of the literature published from 1976 through 2009 were conducted to identify studies dealing with modifications in the implant neck area and marginal bone loss for at least a 5-year observation period. The search terms that were used, alone or in combination, were "implant neck," "marginal bone loss," "neck design," "bone resorption," "bone remodeling," and "implant collar." Relevant studies were selected according to predetermined inclusion and exclusion criteria. RESULTS: The initial search yielded 3,517 relevant titles and revealed eight different implant neck configurations and/or methods suggested for the preservation of marginal bone. These methods included changes in implant neck length and design, implant surface characteristics, implant diameter, and/or insertion depth; the addition of microthreads; the use of one-piece implants; and the concept of platform switching. After subsequent filtering, 20 studies were finally selected and involved the following methods: the use of microthreads (1 study); modifications in implant surface characteristics (11 studies), implant diameter (4 studies), or insertion depth (2 studies); the use of one-piece implants (3 studies); and platform switching (1 study). Because of the heterogeneity of the studies, it was not possible to analyze the data statistically. No evidence was found regarding the effectiveness of any specific modification in the implant neck area in preserving marginal bone or preventing marginal bone loss. CONCLUSION: The current literature provides insufficient evidence about the effectiveness of different implant neck configurations in the preservation of marginal bone. Long-term randomized controlled clinical trials are needed to elucidate the effects of such modifications.