A modified surgical flap for root coverage in association with grafting materials.

PURPOSE: To clinically evaluate in humans the effectiveness of a modified flap for root coverage associated with connective tissue graft or acellular dermal matrix graft after a postoperative period of 12 months. MATERIALS AND METHODS: Thirty bilateral gingival recessions were selected and randomly assigned into experimental groups. All of them were treated with a modified surgical flap, with the releasing incisions placed on the mesial and distal line angles of the adjacent teeth, distant from the main defect, providing a broader flap. One site was treated with the autograft and the contralateral site, with the allograft. Probing depth, clinical attachment level, gingival recession, and keratinized tissue width were measured at baseline and after 12 months. RESULTS: Both procedures significantly improved the clinical parameters evaluated, without statistically significant differences between them. While the autograft group had a mean gingival recession reduction from 3.15 to 0.67 mm, in the allograft group, it was from 3.47 to 0.93 mm. CONCLUSION: The extended flap technique can improve the root coverage results using the subepithelial connective tissue graft or the acellular dermal matrix. CLINICAL SIGNIFICANCE: Graft survival plays a decisive role in mucogingival therapy results and the selection of the appropriate surgical technique is important to achieve it. This 12-month randomized study showed that an extended flap is able to improve the results of root coverage of localized gingival recessions not only when using the acellular dermal matrix as shown in a previous study, but also when using the subepithelial connective tissue. On this basis, this surgical technique can be suggested as the procedure of choice for treating this type of defect.

Differences in collagen distribution of healthy and regenerated periodontium. Histomorphometric study in dogs.

Previous studies have shown that there is a relationship between periodontal disease and the distribution of collagen fibers. This study evaluated the distribution of collagen types I and III in regenerated bone and periodontal ligament, comparing them to the tissues near the regenerated area and to the healthy periodontium. In the third (P3) and fourth (P4) mandibular premolars of 5 healthy mongrel dogs, bilaterally, buccal class 2 furcation lesions were surgically created and chronified for 3 weeks. After that, full flaps were elevated and expanded polytetrafluoroethylene (e-PTFE) membranes were adapted, sutured and recovered by the flaps. Two weeks after surgery, two membranes on the same side were removed and the other membranes were removed four weeks after surgery. The dogs were euthanized at 12 weeks following placement of the e-PTFE membranes. P3 and P4 teeth as well as the second premolars (healthy control teeth) and their periodontal tissues were removed and histologically processed for Collagen Quantification (COLQ). The amount of type III collagen was higher in native bone compared to the regenerated area. For periodontal ligament, COLQ for type I collagen showed statistically significant differences (Tukeys's Multiple Comparison, p⟨0.05) between the regenerated groups and the control group. These differences were not found for type III COLQ. There are significant differences in collagen distribution among the regenerated, native and control tissues. Membrane removal 2 or 4 weeks postoperatively did not influence the collagen composition.

Histologic evaluation of the buccal and lingual bone plates in anterior dog teeth: possible influence on implant dentistry.

BACKGROUND: Recent studies in animals have shown pronounced resorption of buccal bone plate after immediate implantation. The sectioning of experimental material for histologic evaluation of the bone plates could provide valuable information about the possible effect of bone exposure in periodontal and implant surgeries. METHODS: Twenty-four incisors were collected from dogs. After decalcification, the blocks were immersed in paraffin and bucco-lingual histologic sections were examined under light microscope. Some sections were reserved for immunohistochemical analysis. RESULTS: The bone density, the width of the bone plates, and the percentage of vessels presented in the periodontal ligament and periosteum were analyzed in the buccal and lingual bone plates, which were divided corono-apically into thirds. The buccal bone plates showed statistically higher bone density compared to the lingual bone plates in the coronal thirds. The width of both bone plates increased from the coronal to the apical third, but all the buccal thirds were significantly thinner compared to the lingual thirds. No statistically significant differences were found between the bone plates for the percentage of area occupied by the blood vessels in the periodontal ligament or periosteum. CONCLUSION: It is reasonable to conclude that the higher bone density, represented by the lower number of marrow spaces, in association with the thinner aspect of the buccal bone plates made them more fragile to absorb compared to the lingual bone plates, especially during mucoperiosteal procedures.

The bone formation capabilities of the anorganic bone matrix-synthetic cell-binding peptide 15 grafts in an animal periodontal model: a histologic and histomorphometric study in dogs.

BACKGROUND: The aim of this study is to verify the regenerative potential of particulate anorganic bone matrix-synthetic peptide-15 (ABM-P-15) in class III furcation defects associated or not with expanded polytetrafluoroethylene membranes. METHODS: Class III furcation defects were produced in the mandibular premolars (P2, P3, and P4) of six dogs and filled with impression material. The membranes and the bone grafts were inserted into P3 and P4, which were randomized to form the test and control groups, respectively; P2 was the negative control group. The animals were sacrificed 3 months post-treatment. RESULTS: Histologically, the complete closure of class III furcation defects was not observed in any of the groups. Partial periodontal regeneration with similar morphologic characteristics among the groups was observed, however, through the formation of new cementum, periodontal ligament, and bone above the notch. Histologic analysis showed granules from the bone graft surrounded by immature bone matrix and encircled by newly formed tissue in the test group. The new bone formation area found in the negative control group was 2.28 + or - 2.49 mm(2) and in the test group it was 6.52 + or - 5.69 mm(2), which showed statistically significant differences for these groups considering this parameter (Friedman test P <0.05). There was no statistically significant difference among the negative control, control, and test groups for the other parameters. CONCLUSIONS: The regenerative potential of ABM-P-15 was demonstrated through new bone formation circumscribing and above the graft particles. The new bone also was accompanied by the formation of new cementum and periodontal ligament fibers.

Salivary interleukin-6, matrix metalloproteinase-8, and osteoprotegerin in patients with periodontitis and diabetes.

BACKGROUND: Diabetes and periodontitis produce a protein discharge that can be reflected in saliva. This study evaluates the salivary concentrations of interleukin (IL)-6, matrix metalloproteinase (MMP)-8, and osteoprotegerin (OPG) in patients with periodontitis with type 2 diabetes. METHODS: Whole saliva samples were obtained from 90 subjects who were divided into four groups: healthy (control; n = 22), untreated periodontitis (UPD; n = 24), diabetes mellitus (DM; n = 20), and UPD + DM (n = 24) groups. Clinical and metabolic data were recorded. Salivary IL-6, MMP-8, and OPG concentrations were determined by a standard enzyme-linked immunosorbent assay. RESULTS: The UPD and UPD + DM groups exhibited higher salivary IL-6 than the control and DM groups (P <0.01). The salivary MMP-8 concentrations in all diseased groups (UPD, DM, and UPD + DM) were higher than in the control group (P <0.01). The salivary OPG concentrations in the DM group were higher than in the UPD and control groups (P <0.05). In the UPD + DM group, salivary IL-6 was correlated with glycated hemoglobin (HbA1c) levels (r = 0.60; P <0.05). The regression analysis indicated that the number of remaining teeth, clinical attachment level, and IL-6 might have influenced the HbA1c levels in patients with diabetes. CONCLUSIONS: Salivary IL-6 concentrations were elevated in patients with periodontitis with or without diabetes. Salivary MMP-8 and OPG concentrations were elevated regardless of periodontal inflammation in patients with diabetes. Therefore, periodontitis and diabetes are conditions that may interfere with protein expression and should be considered when using saliva for diagnoses.

Replacement of hopeless retained primary teeth by immediate dental implants: a case report.

Hopeless retained primary teeth without permanent successors represent a restorative challenge for clinicians, along with esthetic and functional problems for patients. While various treatment approaches for congenitally missing teeth have been proposed, the replacement of a missing tooth with a dental implant offers specific advantages, such as preservation of the alveolar crest and elimination of the need to restore the adjacent teeth, over other options for tooth replacement. The aim of this article was to illustrate the surgical and prosthetic treatment with implants of a patient with primary teeth without permanent successors.

Subepithelial connective tissue graft for root coverage in smokers and non-smokers: a clinical and histologic controlled study in humans.

BACKGROUND: The aim of this study was to evaluate root coverage of gingival recessions and to compare graft vascularization in smokers and non-smokers. METHODS: Thirty subjects, 15 smokers and 15 non-smokers, were selected. Each subject had one Miller Class I or II recession in a non-molar tooth. Clinical measurements of probing depth (PD), relative clinical attachment level (CAL), gingival recession (GR), and width of keratinized tissue (KT) were determined at baseline and 3 and 6 months after surgery. The recessions were treated surgically with a coronally positioned flap associated with a subepithelial connective tissue graft. A small portion of this graft was prepared for immunohistochemistry. Blood vessels were identified and counted by expression of factor VIII-related antigen-stained endothelial cells. RESULTS: Intragroup analysis showed that after 6 months there a was gain in CAL, a decrease in GR, and an increase in KT for both groups (P <0.05), whereas changes in PD were not statistically significant. Smokers had less root coverage than non-smokers (58.02% +/- 19.75% versus 83.35% +/- 18.53%; P <0.05). Furthermore, the smokers had more GR (1.48 +/- 0.79 mm versus 0.52 +/- 0.60 mm) than the non-smokers (P <0.05). Histomorphometry of the donor tissue revealed a blood vessel density of 49.01 +/- 11.91 vessels/200x field for non-smokers and 36.53 +/- 10.23 vessels/200x field for smokers (P <0.05). CONCLUSION: Root coverage with subepithelial connective tissue graft was negatively affected by smoking, which limited and jeopardized treatment results.

Effect of in vitro gingival fibroblast seeding on the in vivo incorporation of acellular dermal matrix allografts in dogs.

BACKGROUND: Acellular dermal matrix allograft (ADMA) has been used in various periodontal procedures with successful results. Because ADMA has no blood vessels or cells, slower healing and incorporation are observed compared to a subepithelial connective tissue graft. Fibroblasts accelerate the healing process by regulation of matrix deposition and synthesis of a variety of growth factors. Thus, the objective of this study was to evaluate histologically if gingival fibroblasts affect healing and incorporation of ADMA in dogs when used as a subepithelial allograft. METHODS: Gingival fibroblasts were established from explant culture from the connective tissue of keratinized gingiva collected from the maxilla of seven mongrel dogs. ADMA was seeded with gingival fibroblasts and transferred to dogs. Surgery was performed bilaterally, and the regions were divided into two groups: ADMA+F (ADMA containing fibroblasts) and ADMA (ADMA only). Biopsies were performed after 2, 4, and 8 weeks of healing. RESULTS: The quantity of blood vessels was significantly higher in the ADMA+F group at 2 weeks of healing (Kruskal-Wallis; P <0.05). There was no statistical difference (P >0.05) in the number of cell layers, epithelial area, or inflammatory infiltrate between the two groups at any stage of healing. CONCLUSION: The enhanced vascularization in vivo in early stages supports the important role of fibroblasts in improving graft performance and wound healing of cultured graft substitutes.

Preprosthetic periodontal surgery in the proximal area with modification of the col area: results following the reestablishment of the contact point.

BACKGROUND: Anatomic characteristics of interproximal areas are dependent on the anatomy, position, and proximal contact of adjacent teeth. The objective of this study was to investigate the influence of the reestablishment of the interproximal contact following the restorative alveolar interface (RAI) procedure on the interproximal gingival COL and formation of the interdental gingival papilla. METHODS: Six mongrel dogs received bilateral apically positioned flaps, crown lengthening, and the RAI procedure on the maxillary fourth bicuspid and first molar. After 2 weeks, in a randomized manner, one side was prepared to receive metallic crowns and the opposite side remained as the control. The crowns were cemented at the 4-week postoperative period, and the dogs were sacrificed after another 4 weeks, totaling a period of 4 weeks with the full crowns in position and a total of 8 postoperative weeks. Histologic specimens were stained with hematoxylin and eosin and Mallory dyes. Sections 6 micro m thick were obtained in a bucco-lingual plane allowing ample visualization of the interproximal area. RESULTS: Clinical measurements revealed that, in the restored sides, four animals had complete fill of the interdental spaces with gingival papilla, whereas the other two dogs had a distance from the contact point to the tip of papilla varying from 0.02 to 0.021 mm. In the control group, papillae were totally reepithelialized with keratinized epithelium and a convex form. The epithelium completely covered the connective tissue and showed both epithelial projections and surface desquamation. On the test group, despite the presence of the prosthesis, the COL morphology modified by preprosthetic surgery was not altered, presenting a convex papilla with a triangular form and with a keratinized epithelium. Additional histologic characteristics were the same as found in the control group. CONCLUSION: Based on the results of this study, the reestablishment of the contact point does not revert what was obtained with the RAI procedure; the interproximal tissues remain convex and keratinized.

Effect of early membrane removal on regeneration of Class II furcation defects in dogs.

BACKGROUND: This study evaluated the influence of early removal of an expanded polytetrafluoroethylene (ePTFE) membrane on periodontal regeneration. METHODS: The third and fourth mandibular bicuspids of six healthy mongrel dogs were used. Class II furcation lesions were surgically created making lesions chronic for 21 days. Full flaps were elevated, and ePTFE membranes were adapted over the defects. The membranes were removed at 2 weeks on the experimental sides (test group [TGr]) and at 4 weeks on the control side (control group [CGr]). The dogs were sacrificed 12 weeks following placement of the membranes, and the teeth were histologically processed. Area measurements of new tissue (NT), epithelium (EP), connective tissue (CT), and new bone (NB) and linear measurements of bone height (BH) and new cementum (NC) were made. Wilcoxon signed rank test (P <0.05; N = 6) was carried out to determine differences between groups. RESULTS: The area measurements (in mm2) for TGr and CGr, respectively, were as follows: 14.32 +/- 4.01 and 12.46 +/- 3.54 (NT); 0.04 +/- 0.09 and 0.01 +/- 0.04 (EP); 2.31 +/- 2.60 and 1.91 +/- 2.96 (CT); and 9.56 +/- 3.77 and 8.79 +/- 2.99 (NB). The results of the linear measurements (in mm) for TGr and CGr, respectively, were as follows: 3.85 +/- 1.21 and 4.03 +/- 0.94 (BH) and 10.91 +/- 1.72 and 10.59 +/- 1.80 (NC). There were no statistically significant differences between TGr and CGr for any measurement. CONCLUSION: The early removal of ePTFE membranes in Class II furcation defects in dogs did not affect periodontal regeneration.

Amelogenesis imperfecta and unusual gingival hyperplasia.

BACKGROUND: Amelogenesis imperfecta (AI) is a group of hereditary conditions that primarily involves the defective formation and/or calcification of enamel. The association of AI with gingival enlargement-like lesions has also been reported. METHODS: This paper reports a case of a hypoplastic AI associated with unusual generalized gingival hyperplasia. RESULTS: Histological aspect of the gingival growth was characterized by a dense connective tissue with a mild mononuclear inflammatory infiltrate, calcified bodies, and islands of odontogenic epithelium. CONCLUSION: The present case represents a very interesting demonstration of the fact that, although rare, AI may be associated with generalized gingival enlargement.