Selim Ersanli’s research while affiliated with Istanbul University and other places

The aim of this study was to compare the topographical, chemical and osseointegration characteristics of sandblasting and acid-etching (SLA) surfaces and dental implants treated by boron compounds. Titanium (Ti) disks (n = 20) were modified using boron (B) and boric acid (H3BO3) and then compared with the conventional SLA surface via surface topographic characterizations. Dental implants (3.5 mm in diameter and 8 mm in length) with the experimental surfaces (n = 96) were inserted into the tibias of six sheep, which were left to heal for 3 and 7 weeks. Histologic, histomorphometric (bone–implant contact (BIC%)) and mechanical tests (removal torque value (RTV)) were performed. The boron-coated surface (BC group) was smoother (Rz: 4.51 μm ± 0.13) than the SLA (5.86 μm ± 0.80) and the SLA-B (5.75 μm ± 0.64) groups (p = 0.033). After 3 weeks, the highest mean RTV was found in the SLA group (37 N/cm ± 2.87), and the difference compared with the BC group (30 N/cm ± 2.60) was statistically significant (p = 0.004). After 7 weeks, the mean RTV was >80 N/cm in all groups; the highest was measured in the H3BO3-treated (BS) group (89 N/cm ± 1.53) (p < 0.0001). No statistically significant differences were found in the BIC%s during both healing periods between the groups. H3BO3 seems to be a promising medium for dental implant osseointegration.

Background and Objectives: Guided bone regeneration (GBR) surgeries are used for dental implant placements with insufficient bone volume. Biomaterials used in GBR are expected to produce sufficient volume and quality of bone swiftly. This study aims to histologically evaluate the effectiveness of the use of Hyalonect membranes alone or with autogenous grafts in intraosseous defects. Materials and Methods: This study is an experimental study on sheep. Surgeries were performed under general anesthesia in accordance with ethical rules. Five 10 mm defects were surgically created in each ilium of six sheep. One defect was left empty in each ilium (group ED). The defects in the experimental group were covered with Hyalonect membrane while unfilled (group HY) or after being filled with autogenous bone grafts (ABG) (group G+HY). In the control group, the defects were either covered with collagen membrane while unfilled (group CM) or after being filled with the ABG group (G+CM). The sheep were histologically and histomorphometrically evaluated after being postoperatively sacrificed in the third and sixth week (three animals in each interval). Results: All animals completed the study without any complications. No difference was found between groups in the third and sixth weeks regarding the inflammation, necrosis, and fibrosis scores. The G+CM (52.83 ± 3.06) group was observed to have a significantly higher new bone formation rate than all the other groups in the third week, followed by the G+HY group (46.33 ± 2.25). Similar values were found for HY and CM groups (35.67 ± 4.55 ve 40.00 ± 3.41, respectively, p = 0.185), while the lowest values were observed to be in group ED (19.67 ± 2.73). The highest new bone formation was observed in group G+CM (82.33 ± 4.08) in the sixth week. There was no difference in new bone formation rates between groups G+CM, G+HY (77.17 ± 3.49, p = 0.206), and CM (76.50 ± 2.43, p = 0.118). The insignificant difference was found ED group and group HY (55.83 ± 4.92, 73.50 ± 3.27, respectively, p = 0.09). The residual graft amount in the G+CM group was found to be statistically significant at 3 weeks (p = 0.0001), compared to the G+HY group, and insignificantly higher at the 6th week (p = 0.4). Conclusions: In this study, close values were observed between G+HY and G+CM groups. Further experimental and clinical studies with different graft materials are required to evaluate the effectiveness of HY in GBR.

Bone defects lead to aesthetic and functional losses, causing dental rehabilitation to be more difficult. The objective of this work is to histologically assess the hard tissue healing of bone defects filled with platelet-rich fibrin (PRF) alone or as an adjuvant for mixing with and covering anorganic bovine bone (ABB), compared to ABB covered with a resorbable collagen membrane (CM). This study was designed as a crossover animal study. Four 5-mm tibia defects, 5 mm apart from each other, were surgically created on the tibias of 6 sheep. The defects were randomly filled with ABB + CM; PRF alone; ABB+PRF; or were left empty. The animals were euthanized on days 10, 20, and 40 post-operatively. No group showed any signs of bone necrosis. Inflammation was observed in 2 control and 3 test defects with no statistically significant difference between groups at each time point. The ABB + CM and ABB + PRF groups experienced the highest bone regeneration ratios. No differences between the empty-defect and PRF groups were observed in regard to bone regeneration. No statistical difference was observed between the ABB+PRF and ABB + CM groups in regard to bone regeneration and the amount of residual graft material at each time point. The use of PRF should be preferred due to its autogenous origin, low cost, and ease of use.

Objective Parathyroid hormone (PTH) enhances bone healing. Strontium ranelate (SR) is an antiresorptive agent that increases bone formation. Reports about combined effects of PTH and SR on local bone regeneration in osteoporotic subjects are limited. We aimed at investigating the efficacy of PTH and SR for promoting new bone formation in critical sized defects of ovariectomized rats. Materials and Methods PTH‐ and/or SR‐containing poloxamer implant tablets with/without chitosan microparticles were delivered locally to calvarial defects of 90 Wistar rats. Biopsies were analyzed histologically and histomorphometrically at 4 and 8‐week of healing. Results Histomorphometry revealed that PTH alone promoted new bone formation at 4 weeks but the efficiency declined in 8 weeks. There was no positive effect of SR alone on bone formation at 4 or 8 weeks. Calvarial defects treated with PTH+SR combinations showed statistically significant greater new bone formation than either treatment alone at both time intervals. Tissue responses were modest and supported the good biocompability of the biomaterials used. Conclusion PTH and SR combinations can be effective for calvarial bone regeneration of ovariectomized rats. PTH plus SR may have potential use as bone graft material in orthopaedic and dental surgery to enhance bone healing and osseointegration. This article is protected by copyright. All rights reserved.

In dental implant treatment, the atrophic alveolar crest remains a challenging area for optimum rehabilitation. Growth factors have great potential for bone regeneration at the atrophied alveolar crest. Among the various growth factors, recombinant human bone morphogenic protein‐2 (rhBMP‐2) and recombinant human platelet‐derived growth factor (rhPDGF) have received a great deal of attention. This study evaluates the efficacy of rhBMP‐2 and rhPDGF‐BB delivered via absorbable collagen sponge (ACS) on bone formation in guinea pig. A total of 24 adult Dunkin‐Hartley guinea pigs aged 6–7 months, weighing 700–800 g were randomly assigned initially into two groups as 15 and 45 days of healing which have 12 animals in each group. Three‐millimeter‐circular bone defects were created on the tibias of animals as 2 defects per each tibia and totally 4 defects per each animal. The four groups in each animal corresponded to the biomaterial used to fill the created bone defects as follows: rhBMP‐2+ACS, rhPDGF‐BB+ACS, ACS only (positive control), and no treatment (empty; negative control). To prevent the possibility of growth factor interactions between two biomaterials, randomization was performed so that rhBMP‐2+ACS and rhPDGF‐BB+ACS were not applied to the same tibia consecutively. New bone formation was evaluated histologically and histomorphometrically at 15 (early healing) and 45 days (late healing). Data were subjected to statistical analysis. Quantities of new bone were analyzed with one‐way ANOVA followed by post hoc Holm‐Sidak testing. Statistical calculations were performed using Sigma Stat for Windows, version 3.0; P < 0.05 was considered to be significant. At day 15, new bone formation was seen at the peripheral portion of the defect where ACS was partly resorbed. Significant fibrous callus formation was observed in the rhBMP‐2+ACS group. The amounts of fibrous callus and newly formed bone trabeculae in the rhBMP‐2+ACS group were significantly higher than in the other groups (P < 0.05). Highest amount of new bone per defect area was seen in the rhBMP‐2+ACS group at the end of day 15. New bone formation in the rhPDGF‐BB+ACS group was lower than that observed in the rhBMP‐2+ACS group on day 15. However, the amount of newly formed bone trabeculae was significantly higher than in the control groups (ACS only and empty; P < 0.05). The ratio of new bone to total defect area increased significantly over time. At the end of day 45, a large part of the ACS had been resorbed. New bone per defect area at day 45 was significantly higher than at day 15 in the rhPDGF BB+ACS group (P ≤ 0.001). In the rhPDGF‐BB+ACS group, at the end of day 45, the defects were almost filled with new bone, and remodeling was determined. At the end of day 45, new bone formation was significantly higher in the rhPDGF‐BB+ACS group than in the control groups (P = 0.007 and P = 0.006 for empty and ACS only groups, respectively). There was no significant difference between the rhBMP‐2+ACS and rhPDGF‐BB+ACS groups at day 45. Advances in suitable carriers, coupled with the osteoinductive effects of rhBMP‐2 and rhPDGF‐BB, could ultimately create a future gold standard for bone grafting. Although further long‐term studies and clinical trials are required, the findings presented herein suggest a promising use of rhBMP‐2 and rhPDGF‐BB for bone regeneration applications.

Purpose: The aim of this study was to evaluate the stability during healing and before loading of implants placed at two different supracrestal levels according to their collar texture. Materials and Methods: This retrospective study included patients who received posterior implants with the same macro design. Implants with a machined collar were placed 0.3 mm above the crestal bone (M group), while those with a laser-microtextured collar were placed 1 mm above the crestal bone (L group). All implants healed in a single stage with healing abutments. Implant stability quotient (ISQ) values were determined using resonance frequency analysis immediately after implant placement during surgery and after 1, 4, 8, and 12 weeks after surgery. Other evaluated factors for stability included the implant diameter and length and the site of placement (maxilla or mandible). Results: In total, 103 implants (47 L, 56 M) were evaluated. The median ISQ values at baseline and 1 week after placement were significantly higher for the M group than for the L group (p=0.006 and p=0.031, respectively). There were no differences at the subsequent observation points. The ISQ value was higher for wide-diameter than regular diameter (p=0.001) and mandibular implants than maxillary implants (p=0.001 at 0-8. weeks; p=0.012 at 12 weeks) at all observation points. When diameter data were neglected, the implant length did not influence the ISQ value at all observation points. Conclusion: Our results suggest that submerging implant more inside bone may only influence primary stability. Moreover, the implant diameter and site of placement influence primary and secondary stability before loading, whereas the implant length does not when its diameter is not accounted for.

Background/purpose: The presence of adequate bone volume is a critical factor in rehabilitative dentistry. Despite the use of many promising alloplasts, success in stimulating bone formation has been limited, mostly due to poor local biological response. Growth factors have been introduced to stimulate angiogenesis and new bone formation. This histologic and histomorphometric study aimed to evaluate the effect of vascular endothelial growth factor (VEGF) and a biphasic alloplastic graft material (BA) on the healing of endosseous defects in rats. Materials and methods: Twenty male Wistar rats were used. Two critical-sized bone defects were created in both the right and left femurs of each rat. Each defect was randomly assigned to be treated with VEGF, BA, or VEGF + BA, or to be left empty as a control. Half of the animals were sacrificed after 1 week, and the remaining half were sacrificed after 2 weeks. Inflammation, necrosis, and new bone areas were evaluated by means of histologic and histomorphometric analyses. Results: Compared to the control group, defects treated with VEGF alone or in combination with BA showed higher rates of bone formation (33.10–46.60%) on Day 7. Additionally, VEGF significantly reduced inflammation and necrosis (P