RESUMO
OBJECTIVE: To assess bone thickness augmentation and implant survival in ridges with horizontal atrophy managed through split crest technique with concomitant installation of dental implants. MATERIALS AND METHODS: Thirteen patients with maxillary bone atrophy underwent surgery and had their bone thickness assessed through cone beam computed tomography 6 months pre- and postoperatively. Comparative measurements of initial and final bone height and thickness were taken using Dolphin Imaging® 11.5 software. The distance between the nasal fossa floor or the maxillary sinus and the alveolar crest determined the bone height, while the measurement of bone thickness took into account the distance between the vestibular cortical bone and the palatal cortical bone at the crest level, and at 5 mm and 10 mm from it. RESULTS: The bone height loss of 0.68 mm was statistically significant (p = 0.01). The average horizontal bone gain was 3.45 mm at ridge level, 3.03 mm at 5 mm from it and 2.42 mm at 10 mm from it. The mean horizontal gain for the three regions was 2.97 mm, and the values were statistically significant for all three regions assessed (p < 0.01). No complications were associated with the surgical procedures, and 23 implants were installed following the surgical expansion. No implants were lost (100% survival). CONCLUSION: The split crest technique proved to be viable and predictable, enabling a significant increase in ridge thickness and a high percentage of implant survival.
RESUMO
This study tested the fracture strength of prosthetic abutments with different sizes and combinations to support a 5-implant milled framework with distal extension. Prosthetic abutments with different dimensions (4.8-mm diameter mini conical abutment and 3.5-mm diameter microconical abutment) were screwed to 5 threaded implants. The following groups were divided (n = 3): G1 with 5 miniconical abutments (standard size), G2 with 5 microconical abutments (small sized), G3 with a combination of 3 small sized abutments and 2 standard sized abutments, and G4 with a combination of 2 small sized abutments and 3 standard sized abutments. Standardized titanium frameworks for full-arch fixed dental prosthesis were milled with equidistant holes for each of the 5 implants and abutments. A loading point was selected at 18 mm away from both distal implants. A universal testing system was used for the fracture strength tests and load was applied at a crosshead speed of 0.5 mm/min on the previously described loading points until component fracture. Mean fracture strength for each group was statistically compared (α = 0.05). Prosthetic screws were the only fractured components for all tested groups. Mean fracture strength was: G1, 1130.22 N; G2, 1031.36 N; G3, 757.9 N; and G4 792.03 N (P < .05). All prosthetic abutments and combinations that were tested provide adequate fracture strength for clinical use. However, the combination of standard and small diameter abutments leads to lower fracture strength compared with when only standard sized prosthetic abutments were used, irrespective of the abutment diameter (4.8- or 3.5-mm).