Augmentation of single tooth extraction socket with deficient buccal walls using bovine xenograft with platelet-rich fibrin membrane.

BACKGROUND: Different techniques and materials such as bone grafts and bioactive agents have been used for alveolar ridge augmentation in extraction sockets with a defective wall, there is not a specific material or technique that has resulted in superior outcomes or prevented total bone loss. OBJECTIVES: This clinical study aims to evaluate radiographically the effectiveness of using bovine xenograft with platelet-rich fibrin (PRF) membrane on vertical and horizontal alveolar ridge dimensional changes following tooth extraction that are complicated by buccal bone loss. MATERIALS AND METHODS: This study was conducted in Egypt on fourteen patients with a single posterior tooth indicated for extraction. A preoperative cone-beam computed tomography (CBCT) scan confirmed more than 50% loss in buccal bone in each tooth. Extraction sockets were packed with minced PRF clots mixed with a bovine xenograft. Each extraction socket was sealed by PRF membranes. CBCT scans, performed before tooth extraction and after 6 months, were used to assess alveolar ridge changes both vertically and horizontally. RESULTS: There was a significant gain in the buccal and middle of the extraction socket bone height, recording 86.01% (6.33 mm) and 206.45% (9.6 mm), respectively. There was an insignificant bone loss in the lingual bone height and width, recording - 8.49% (-1.06 mm) and - 13.39% (1.05 mm), respectively. The results also showed a non-significant decrease in alveolar bone density (-14.06%) between pre-operative bone present apical to the extraction socket and newly formed bone inside the socket. CONCLUSIONS: Ridge preservation/augmentation techniques using a bone graft mixed with PRF and covered by PRF membranes in fresh extraction sockets complicated by the loss of buccal bone result in buccal bone augmentation and a reduction in horizontal and vertical ridge collapse after tooth extraction. CLINICAL RELEVANCE: The bovine xenograft in conjunction with PRF can be used immediately after extraction for ridge preservation, providing adequate bone width and height for implant placement.

Milled Bar with PEEK and Metal Housings for Inclined Implants Supporting Mandibular Overdentures: 1-Year Clinical, Prosthetic, and Patient-Based Outcomes.

PURPOSE: This investigation aimed to evaluate clinical, prosthetic, and patient-based outcomes of a milled bar with polyether ether ketone (PEEK) and metal housings for inclined implants supporting mandibular overdentures. MATERIALS AND METHODS: Eighteen edentulous participants received four implants in the interforaminal area of the mandible (two vertically and two distally inclined), and implants were connected with milled bars. Overdentures were attached to the bars with PEEK female housing (test group). The control group consisted of participants who received milled bar overdentures with conventional metal housings but were case matched to the test group and served as a historical cohort. Clinical parameters (Plaque Index, Gingival Index, pocket depth, and bone loss) were measured at baseline, 6 months, and 12 months. Patient satisfaction (using visual analog scale) and prosthetic complications were recorded after 12 months. RESULTS: The control group showed a significantly higher plaque score and marginal bone resorption compared with the test group. The test group showed higher satisfaction with retention, stability, speech, and esthetics compared with the control group (P < .048). The test group showed a significantly lower incidence of female housing wear (P = .017), plastic clip wear (P < .001), and plastic clip fracture/renewal (P = .049) than the control group. No difference between groups was noted for other clinical, prosthetic, and patient-based outcomes. CONCLUSION: PEEK housing of a milled bar may be a successful alternative to conventional metal housing for inclined implants supporting mandibular overdentures, as it is associated with favorable clinical, prosthetic, and patient-based outcomes after 1 year.

The Influence of Implant Inclination on Retention and Peri-implant Stresses of Stud-Retained Implant Overdentures During Axial and Nonaxial Dislodgments: An In Vitro Study.

PURPOSE: The purpose of this study was to evaluate the influence of implant inclination on retention and peri-implant stresses of stud-retained implant overdentures during axial and nonaxial dislodgments. MATERIALS AND METHODS: Mandibular acrylic models (n = 4) received two implants in the canine areas with 0-, 5-, 10-, and 20-degree lingual inclinations. Dentures were attached to the implants with stud connectors. Four strain gauges were bonded at buccal, lingual, mesial, and distal surfaces of each implant to monitor strains around implants. Retention values (Newton) and peri-implant stresses (microstrains, µs) were recorded during axial (vertical) and nonaxial (anterior, posterior, and lateral) dislodging. A general linear model was used to compare retention forces and implant stresses between implant inclinations and dislodging direction. In addition, a linear regression model was used to test correlation of implant stresses with confounding factors. RESULTS: The highest retention and implant stresses were noted with 0 degrees, followed by 5 and 10 degrees (without difference), and the lowest values were noted with 20 degrees. Anterior dislodging was associated with the highest retention and implant stresses, followed by vertical dislodging, then lateral dislodging, and posterior dislodging. Peri-implant stresses significantly correlated with dislodging direction and retention forces. Every 1 N of increase in retention forces causes 19.17 µs increase in implant stresses. Anterior dislodging was associated with the highest predicted stress values (846.0 µs), and the lowest stress values (143.41 µs) were associated with posterior dislodging. CONCLUSION: Retention forces and peri-implant stresses decreased as lingual implant inclination increased during axial and nonaxial dislodging of stud-retained implant overdentures. Peri-implant stresses were significantly correlated with dislodging direction and retentive forces.