Background Various approaches are used for alveolar ridge preservation (ARP); however, there is no standard method or material. Purpose To investigate the effect of ARP with a dense polytetrafluoroethylene (d‐PTFE) membrane and freeze‐dried irradiated allogenic bone for sockets with bone deficiency. Materials and Methods Thirty‐four patients (with sockets exhibiting ≥3 mm hard tissue loss in ≥1 walls) were randomized to undergo natural socket healing (control) or ARP with a d‐PTFE membrane and freeze‐dried irradiated allogenic bone (test group). After 4 months, horizontal and vertical ridge changes were measured using cone beam computed tomography. Results Ridge width at l mm below the ridge crest demonstrated significantly less change in the test group (median =2.3; Q1 = 0.6; Q3 = 4.3 mm) than in the control group (median =3.9; Q1 =2.6; Q3 = 7.8 mm; P = .021). There was no significant difference between the two groups in horizontal ridge changes at 3 and 5 mm below the crest or vertical changes ( P > .05). Requirement for bone augmentation at implant placement was significantly reduced in the test group compared to the control group ( P < .001). Conclusion ARP with a d‐PTFE membrane and freeze‐dried irradiated allogenic bone substitute reduced horizontal bone resorption in sockets with bone deficiency.

PURPOSEThe objective of this study was to conduct an in vitro comparative evaluation of polished and laserdimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti.MATERIALS AND METHODSForty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had 5-µm dimples at 10-µm intervals, and SM30 (n=16) had 5-µm dimples at 25-µm intervals in a 2 × 4 mm2 area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences.RESULTSThe adhesion strength of epithelial cells was higher on Ti surfaces with 5-µm laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins.CONCLUSIONThese findings demonstrate that laser dimpling may contribute to improving the periimplant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment.

The aim of this study was to elucidate the role of 2 types of collagen membranes (cross-linked vs noncross-linked) used in conjunction with autogenous or allogenic bone followed by xenogeneic bone particles for dehiscence defect around implants in humans. Experimental groups were divided into 2 groups: Group CL (cross-linked, Ossix Plus, n = 24 implants, 16 patients) and Group NCL (noncross-linked, Bio-Gide, n = 25 implants, 18 patients). At the time of implant insertion and uncovery surgery, measurements of the dehiscence bony height, width, and surface area were made. Before applying the membrane to defects, guided bone regeneration was performed. Because it is difficult to measure the degree of exposure, early exposed cases were excluded from the result analysis. The mean percentage gain of the dehiscence defect and the mean marginal bone reduction value of follow-up radiograph did not show statistically significant differences between the 2 groups. Both membranes exhibited satisfactory results on dehiscence defects. As a result, our authors concluded the success of guided bone regeneration was performed simultaneously for dehiscence defects around the implant, regardless whether collagen membranes were cross-linked or noncross-linked.

Vertical ridge augmentation for long-term implant stability is difficult in severely resorbed areas. We examined the clinical, radiological, and histological outcomes of guided-bone regeneration using novel titanium-reinforced microporous expanded polytetrafluoroethylene (MP-ePTFE) membranes. Eighteen patients who underwent implant placement using a staged approach were enrolled (period: 2018–2019). Vertical ridge augmentation was performed in areas with vertical bone defects ≥ 4 mm. Twenty-six implant fixtures were placed in 14 patients. At implant placement six fixtures had relatively low stability. On cone-beam computed tomography, the average vertical changes were 4.2 ± 1.9 (buccal), 5.9 ± 2.7 (central), and 4.4 ± 2.8 mm (lingual) at six months after vertical ridge augmentation. Histomorphometric analyses revealed that the average proportions of new bone, residual bone substitute material, and soft tissue were 34.91 ± 11.61%, 7.16 ± 2.74%, and 57.93 ± 11.09%, respectively. Stable marginal bone levels were observed at 1-year post-loading. The residual bone graft material area was significantly lower in the exposed group (p = 0.003). There was no significant difference in the vertical height change in the buccal side between immediately after the augmentation procedure and the implant placement reentry time (p = 0.371). However, all implants functioned well regardless of the exposure during the observation period. Thus, vertical ridge augmentation around implants using titanium-reinforced MP-ePTFE membranes can be successful.