Search

Purpose: To answer the following question: 'Do recombinant, purified, and concentrated growth factors enhance the regenerative potential of particulate bone graft substitutes in maxillary sinus floor augmentation (MSA)?', Materials and Methods: Human studies comparing histomorphometric data on new bone formation, residual graft material, and fibrous tissue ratio (outcomes of interest) following MSA procedures employing particulate bone grafts/substitutes in combination or not with growth factors were retrieved from PubMed/MEDLINE, Web of Science, Cochrane, and Scopus online databases and complemented with a hand search. Controlled studies published in English up to December 2022 and reporting on histomorphometric data expressed as volume percentage of the outcomes of interest were considered. Risk of bias was assessed, and a meta-analysis was performed to investigate the effects of supplementary growth factors on new bone formation, remaining graft particles, and fibrous tissue ratio., Results: Data were included from 613 samples in 477 patients reported in 22 publications. Meta-analysis showed that platelet-rich plasma or platelet-rich fibrin resulted in 49% more new bone formation than in control group areas (P &#61; .004), and those areas supplemented with growth factors presented 57% less residual graft particles after healing (P < .0001). A significant (P &#61; .03) 1.85-fold increase in connective tissue formation was noted in areas treated with recombinant human bone morphogenetic proteins (rhBMPs) after healing., Conclusions: Selective supplementary growth factors may enhance new bone formation and accelerate particulate graft turnover, while rhBMP may significantly increase connective tissue formation in MSA procedures in humans.

Buccal bone walls present significant resorption after tooth extraction, possibly related to the smaller bone thickness, length, and the sagittal position of the root, as well as the bone morphology. The goal of the present study was to measure the thickness of the cortical bone of the vestibular and palatal walls in the anterior maxilla by means of CBCT images. Measurements were taken from CBCT scans of 300 maxillary anterior teeth from 50 patients (25 women, 25 men) aged 18 to 30 years. The parameters evaluated included the thickness of the buccal and palatal cortical bone in the cervical, apical, and middle thirds of the root, as well as six specific angular measurements from each tooth. The lateral incisors showed a significant difference in thickness between each of the buccal and palatal thirds, and measurements were also significantly smaller than the central and canine incisors. Bone anatomy is tooth-and location-specific, and thus the sagittal root position within the alveolus influences the regional bone morphology and may explain the gingival zenith position in the anterior maxilla. These specific buccal and palatal anatomic parameters should be carefully taken into consideration for surgical planning and intervention in the esthetic area.

Histologic and histomorphometric evaluations of gingival biopsy samples of patients presenting either a thick or a thin gingival biotype were performed. Full-thickness gingival biopsy samples were obtained and processed for histologic and histometric evaluations. Thickness of the keratinized mucosa or gingiva was found to be increased in the thick biotype. Specifically, the connective tissue layer was thicker with no change in epithelial thickness. In conclusion, gingival transparency appears to be an adequate, clinically useful method to classify the gingival biotype. The thin gingival biotype is manifested by reduced connective tissue thickness; therefore, biotype conversion or enhancement may be based on augmentation of the connective tissue portion of the gingival tissues.

This study compared the clinical outcomes of recombinant human platelet-derived growth factor BB and beta-tricalcium phosphate (rhPDGF-BB/βTCP) with guided bone regeneration (GBR) in immediate implant placement in molar extraction sockets with buccal bone defects versus conventional implant placement. Twenty-eight implants were placed in fourteen patients. Clinical and radiographic evaluations assessed peri-implant soft and hard tissue parameters after 12 months. No implants were lost during the 1-year observation period, yielding a survival rate of 100%. Similar clinical and radiographic parameters were observed for both treatment groups. Use of rhPDGF-BB/βTCP and GBR in immediate implants in molars was as successful as conventional implant placement in fully healed extraction sites.

Purpose: The objective of this study was to evaluate the efficacy of guided bone regeneration (GBR) employing recombinant human platelet-derived growth factor-BB (rhPDGF-BB) incorporated into a beta-tricalcium phosphate (β-TCP)/hydroxyapatite (HA) carrier as a graft material and to compare it to autogenous bone block grafting., Materials and Methods: Adult patients with a site that required bone grafting to increase the thickness of the alveolar bone ridge were treated. After mucoperiosteal flap elevation, experimental bone defects were treated by GBR with rhPDGF incorporated into β-TCP/HA, and control defects were treated with autogenous bone. Primary tension-free wound closure was obtained for all treated sites., Results: Thirty patients were treated. No significant differences were observed between the groups for any of the parameters evaluated, including the amount of bone regeneration and a need for additional grafting., Conclusion: A composite bone ceramic graft that incorporated rhPDGF appears to be a suitable substitute for autogenous bone block grafting when employed in conjunction with GBR in humans.

Purpose: Bone formation and healing are diminished in experimental type 1 diabetes. The present study investigated whether controlled local release of recombinant human bone morphogenetic protein 2 (rhBMP-2) stimulates bone defect healing in diabetes as a consequence of its anabolic effects on bone., Materials and Methods: Bilateral experimental circular bone defects were created in the temporal bones of 64 BALB/cByJ mice. Defects were treated with acellular collagen sponge plus 0.4 or 1.8 μg of rhBMP-2 per defect, and untreated defects served as controls. The healing of the defects over a 14-day period in diabetic and nondiabetic mice was analyzed histomorphometrically., Results: Diabetes inhibited bone formation in both untreated and BMP-treated bone defects. Controlled local release of rhBMP-2 significantly stimulated bone formation in diabetic animals, bringing it nearly to normal levels, and enhanced bone regeneration in normal animals., Conclusion: Recombinant human BMP-2 may be beneficial in treating deficient intramembranous bone formation in diabetes.

Purpose: Soft tissue closure is mandatory for optimal healing of extraction sites treated via guided bone regeneration. The objective of this study was to evaluate the efficacy of a flap design based on the extension of palatal tissues to obtain and maintain soft tissue coverage over grafted extraction sockets., Materials and Methods: Adult patients (n = 22) with at least two teeth indicated for extraction were treated. After atraumatic extraction, control sockets were filled with a composite graft (1:1) containing demineralized freeze-dried bone allografts and Bio-Oss. Experimental sockets were treated identically, except that an Atrisorb absorbable barrier membrane was also placed over the graft material before flap closure, which was obtained, in all sockets, by the coronal extension of a vascularized pedicle dissected from the periosteal aspect of the palate., Results: Primary tension-free wound closure was achieved at all treated sites. Exfoliation of the graft material during healing was not observed in either treatment group. High levels of soft tissue closure were maintained throughout the study period for both treatment groups, and membrane exposure was observed in only 7% of treated sites., Conclusion: On the basis of this study it appears that the reported technique was an adequate method of achieving and maintaining complete soft tissue coverage and promoting healing by primary intention in grafted extraction sockets in humans.

Purpose: Bone formation and the healing of calvarial defects in mice is diminished in chemically induced type 1 diabetes. The present study investigated whether controlled local release of fibroblast growth factor 2 (FGF-2) stimulates bone defect healing in this model of diabetes., Materials and Methods: First, in vitro release kinetics of different doses of recombinant human FGF-2 (rhFGF-2) from polyglycolate:polylactide membranes was determined over a 14-day period by incubating loaded membranes in PBS with constant shaking. The amount of FGF-2 was measured by enzyme-linked immunosorbent assay. Then, the effects of rhFGF-2-loaded and control membranes on calvarial defect healing over a 14-day healing period were determined in diabetic and nondiabetic mice. The degree of healing was determined by histomorphometric analyses of bone area percentage and by area measurements. The significance of the data was determined by statistical analyses, including analysis of variance., Results: Kinetic release data in vitro showed that membranes loaded with 5 microg FGF-2 released measurable levels of growth factor for more than 14 days. Data from the in vivo study supported the previous finding that diabetes inhibits bone formation. Membranes containing rhFGF-2 significantly (P < .05) stimulated bone formation in diabetic animals to near normal levels during the healing period., Conclusion: FGF-2-loaded membranes may be useful in further studies aimed at developing therapeutic strategies for correcting deficient bone healing in patients with diabetes.

The aim of this study was to investigate postsurgical periodontal probe penetration by using clinical information and histometric data. Thirty-eight three-walled defects were created in four dogs, then maintained for 3 months. Subsequently, 26 defects were subjected to periodontal surgery (surgical group), while 12 defects served as controls. The dogs were sacrificed at 4, 8, 12, and 16 weeks. Immediately before sacrifice, endodontic silver points were placed in the gingival crevices as substitutes for periodontal probes and fixed on the teeth. Following block sections, histologic and histomorphometric evaluations were undertaken: location of the probe tip in relation to the apical termination of the junctional epithelium, length of new junctional epithelium in relation to the apical junctional epithelium, and mean length of connective tissue adhesion in relation to the apical junctional epithelium. Probe tips were located -1.37 +/- 1.73 mm and -0.20 +/- 0.15 mm apical to the apical junctional epithelium for the surgical and control groups, respectively, at 4 weeks, while the probe tip was located 0.58 +/- 0.31 mm and 0.40 +/- 0.20 mm coronal to the apical junctional epithelium, respectively, at 16 weeks. Length of new junctional epithelium in relation to apical junctional epithelium was significantly less for the surgical than the control group at 4 weeks (0.73 +/- 0.60 mm vs 1.19 +/- 0.02 mm) and 8 weeks (1.77 +/- 0.52 mm vs 2.15 +/- 0.00 mm). There were no significant differences between the groups in regard to connective tissue relationship to the apical junctional epithelium. Periodontal probing is not recommended for at least 2 months after surgical procedures; before this stage, probing forces may damage the soft tissue-tooth interrelationship.