Efficacy of a collagen matrix for soft tissue augmentation after implant placement compared to connective tissue grafts: A multicenter, noninferiority, randomized controlled trial.

OBJECTIVES: To test whether soft tissue volume augmentation using a collagen matrix (VCMX) leads to noninferior results in terms of gain of mucosal thickness at single implant sites, compared to connective tissue grafts (SCTG). METHODS: The study was designed as a multi-center randomized controlled clinical trial. Subjects in need of soft tissue volume augmentation at single tooth implant sites were consecutively recruited at nine centers. The deficient mucosal thickness at the implant sites (one per patient) was augmented by applying either a VCMX or a SCTG. Patients were examined at 120 days (abutment connection = primary endpoint), 180 days (final restoration), and 360 days (1-year after insertion of the final restoration). Outcome measures included: transmucosal probing of the mucosal thickness (crestal = primary outcome), profilometric measurements of the tissue volume, and patient-reported outcome measures (PROMs). RESULTS: Out of the 88 patients, 79 attended the one-year follow-up. The median increase of the crestal mucosal thickness between pre-augmentation and 120 days was 0.3 ± 2.1 mm in the VCMX group and 0.8 ± 1.6 mm in the SCTG group (p = .455). Non-inferiority of the VCMX compared to the SCTG was not observed. The respective numbers at the buccal aspect amounted to 0.9 ± 2.0 mm (VCMX) and 1.1 ± 1.4 mm (SCTG; p = .431). PROMs including pain perception favored the VCMX group. CONCLUSION: It remains inconclusive whether soft tissue augmentation using a VCMX is noninferior to SCTG in terms of crestal mucosal thickening at single implant sites. However, the use of collagen matrices favors PROMs especially pain perception, while achieving similar buccal volume gains along with comparable clinical and aesthetic parameters to SCTG.

Rehabilitation of an edentulous atrophic maxilla with four unsplinted narrow diameter titanium-zirconium implants supporting an overdenture.

The edentulous maxilla is often affected by bone resorption, sometimes making it difficult to place standard diameter implants. Narrow diameter implants made of titanium-zirconium (Ti-Zr) alloy, which has superior mechanical properties compared with titanium, have been proposed for these difficult situations. This retrospective clinical observation reports the outcome of the use of reduced diameter implants made of Ti-Zr alloy supporting maxillary overdentures retained with locator abutments. The charts of all patients who received maxillary overdentures supported by four unsplinted implants from January 2009 to June 2010 at the Department of Periodontology and Prosthodontics, Eastman Dental Hospital, Rome, Italy, were reviewed. All patients treated with four narrow diameter Ti-Zr implants were selected for the present case series. Ten patients were found, six of whom received augmentation procedures. After 12 to 16 months of follow-up, no implants were lost, and only one implant showed bone resorption greater than 1.5 mm. Implants showed a success rate of 97.5% and a survival rate of 100%. All prostheses were successfully in function. The present case series showed promising results regarding the use of narrow diameter implants made of Ti-Zr supporting maxillary overdentures retained with locator abutments.

Reconstruction of the moderately atrophic edentulous maxilla with mandibular bone grafts.

BACKGROUND: Mandibular bone grafts are used for alveolar reconstruction in partially edentulous patients. Few reports describe the use of mandibular bone for total maxillary reconstruction. AIM: To describe indications to the use of extensive mandibular bone grafts for maxillary reconstructions in edentulous patients. METHODS: A retrospective evaluation of a group of patients with edentulous resorbed maxillae reconstructed with mandibular bone grafts in preparation for implant placement was performed. The studied cohort consisted of 15 patients who were treated with mandibular onlay blocks and sinus augmentation with mandibular bone in an outpatient setting under local anesthesia (MG). This approach was chosen when residual bone height in the anterior maxilla was at least 8 mm combined with posterior vertical deficiency and anterior horizontal defects. Success and survival rates of the implants and prostheses together with the achievement of the planned prosthetic plan were recorded. Patients also performed an evaluation of the outcome with the aid of Visual Analog Scales. Mean follow-up time was 19 months after prosthesis delivery. RESULTS: No major surgical complications occurred at recipient or donor sites. A total of 81 implants were inserted, and survival and success rates were 97.6% and 93%, respectively. Planned prostheses could be delivered to all patients (eight overdentures and seven fixed dental prostheses). CONCLUSIONS: With the limitations of the present clinical study, it can be stated that edentulous maxillae with a moderate atrophy may be successfully augmented with mandibular bone grafts in an outpatient setting under local anesthesia and e.v. sedation. This is the case when posterior maxillary deficiency is combined with horizontal defects, but with a residual height of 8 mm or more in the anterior maxilla. When the residual anterior bone height is less than 8 mm, or when the inter-arch discrepancy needs to be corrected with an osteotomy, extraoral bone harvesting needs to be considered.

Retrospective evaluation of mandibular incisor replacement with narrow neck implants.

The authors have retrospectively evaluated the clinical results of mandibular incisors replacement with narrow neck implants (NNI). Thirty-one patients treated consecutively for single or multiple lower incisor replacement with NNI with a mean follow-up of 23 months (range 18-42 months) were included in the study and were divided into three groups: single tooth, multiple unit restoration and restorations on adjacent implants. Survival and success rates and soft tissue parameters such as modified plaque index (mPI), peri-implant probing depth (PPD), bleeding on probing (BOP) and the papilla index were analyzed. Subjective evaluation was performed by patients and clinicians on visual analogue scales. The implants and prostheses showed a survival rate of 100% and an overall success rate of 94%. The distribution of mPI outcomes showed better results for the single tooth group. BOP was present in four of eight implants (50%) in the adjacent implant group, in one out of 20 implants in the single tooth group (5%) and in one out of 16 implants in the multi unit group (6%). The adjacent implant group showed a statistically significant increase in PPD. The Papilla Index showed a better outcome distribution in single tooth and multi unit groups. Patients' evaluation of treatment outcome was satisfactory in all groups, even though the best esthetic and functional results were found in single tooth and multi unit groups. The professional evaluation showed good outcomes for the single tooth and multi unit groups and statistically significant poorer results in the adjacent implants group. With the limitations of this study, it may be concluded that the replacement of lower incisors with NNI leads to favorable functional and esthetic results in cases of single-tooth or multiple-unit replacement. Worse results are achieved if two adjacent mandibular incisors are replaced with adjacent implants.