Morphological and chemical analysis of bone substitutes by scanning electron microscopy and microanalysis by spectroscopy of dispersion energy.

This study evaluated the morphological and chemical composition of the following bone substitutes: cancellous and cortical organic bovine bone with macro and microparticle size ranging from 1.0 to 2.0 mm and 0.25 to 1.0 mm, respectively; inorganic bovine bone with particle size ranging from 0.25 to 1.0 mm; hydroxyapatite with particle size ranging from 0.75 to 1.0 mm; and demineralized freeze-dried bone allograft with particle size ranging from 0.25 to 0.5 mm. The samples were sputter-coated with gold in an ion coater, the morphology was observed and particle size was measured under vacuum by scanning electron microscopy (SEM). The chemical composition was evaluated by spectroscopy of dispersion energy (EDS) microanalysis using samples without coating. SEM analysis provided visual evidence that all examined materials have irregular shape and particle sizes larger than those informed by the manufacturer. EDS microanalysis detected the presence of sodium, calcium and phosphorus that are usual elements of the bone tissue. However, mineral elements were detected in all analyzed particles of organic bovine bone except for macro cancellous organic bovine bone. These results suggest that the examined organic bovine bone cannot be considered as a pure organic material.

Coronally positioned flap for root coverage in smokers and non-smokers: stability of outcomes between 6 months and 2 years.

BACKGROUND: Smoking adversely affects the short-term outcomes of coronally positioned flap (CPF) root coverage procedures, but the long-term stability of this procedure in smokers has not been studied. The objective of this study was to evaluate the effect of smoking on the long-term outcomes of CPF in recession treatment. METHODS: CPF was used to treat a Miller Class I defect in a maxillary canine or premolar in 10 current smokers (> or =10 cigarettes daily for > or =5 years) and 10 non-smokers (never smokers). At baseline and 6, 12, and 24 months, clinical parameters, including probing depth (PD), clinical attachment level (CAL), recession depth (RD), and width of keratinized tissue (KT), were determined. RESULTS: Intragroup analysis showed that CPF failed to maintain the gingival margin at the initially achieved position. RD significantly increased in smokers (from 0.84 +/- 0.49 to 1.28 +/- 0.58 mm) and in non-smokers (from 0.22 +/- 0.29 to 0.50 +/- 0.41 mm) between 6 and 24 months. Further analysis showed that 50% of smokers and 10% of non-smokers lost between 0.5 and 1.0 mm of root coverage in the same period. Intergroup analysis showed that smokers had significantly greater residual recession (P = 0.001) at 24 months. Both smokers and non-smokers lost CAL and experienced decreases in KT. CONCLUSIONS: The long-term stability of CPF outcomes is less than desirable, particularly in smokers. Two years after a CPF procedure, smokers have significantly greater residual recession compared to non-smokers both statistically and clinically.

Coronally positioned flap for root coverage: poorer outcomes in smokers.

BACKGROUND: Gingival recession is significantly more common among smokers, while the relative outcome of various root coverage procedures in smokers, compared to non-smokers, is debatable. The objective of this study was to evaluate the influence of cigarette smoking on the outcome of coronally positioned flap (CPF) in the treatment of Miller Class I gingival recession defects. METHODS: Ten current smokers (> or = 10 cigarettes daily for at least 5 years) and 10 non-smokers (never smokers), each with one 2- to 3-mm Miller Class I recession defect in an upper canine or bicuspid, were treated with CPF. At baseline and 6 months, clinical parameters, probing depth (PD), clinical attachment level (CAL), recession depth (RD), and apico-coronal width of keratinized tissue (KT) were determined. RESULTS: Intragroup analysis showed that CPF was able to reduce RD and improve CAL in both groups (P <0.05). Intergroup analysis demonstrated that smokers presented greater residual RD at 6 months and lower percentage of root coverage (69.3% versus 91.3%; P <0.05). No smokers obtained complete root coverage compared to 50% of non-smokers (P <0.05). CONCLUSIONS: Within the limits of the present study, it can be concluded that CPF provides benefits for both smokers and non-smokers in terms of root coverage of shallow Miller Class I recession defects. However, cigarette smoking negatively impacts the clinical outcomes, specifically residual recession, percent root coverage, and frequency of complete root coverage.

The influence of enamel matrix derivative associated with insulin-like growth factor-I on periodontal ligament fibroblasts.

BACKGROUND: Enamel matrix derivative (EMD) has recently been shown to promote periodontal regeneration in vivo. Insulin-like growth factor-I (IGF-I) is a potent modulator of periodontal regeneration stimulating cell proliferation, differentiation, synthesis of type I collagen, and non-collagenous proteins. However, the biochemical effects of these factors on periodontal ligament (PDL) fibroblasts are not completely understood. The objective of the present study was to evaluate the effect of EMD, IGF-I, and the combination of these two factors on the proliferation, adhesion, migration, and expression of type I collagen in PDL fibroblasts. METHODS: The proliferation rate was measured by automated cell counting and immunohistochemical expression of proliferating cell nuclear antigen (PCNA). The cell adhesion was analyzed by a colorimetric assay and cell migration was measured in Boyden chambers. Type I collagen expression and production was determined by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: The results indicated that the proliferation of PDL fibroblasts was significantly stimulated by EMD and EMD plus IGF-I in a dose- and time-dependent manner. EMD, IGF-I, and the combination of both factors had no effects on cellular migration and adhesion or expression and production of type I collagen. CONCLUSION: Our results showed that EMD, IGF-I, and the combination of both factors stimulated PDL fibroblast proliferation, whereas these factors did not affect adhesion, migration, or expression of type I collagen of these cells.

Root coverage using the coronally positioned flap with or without a subepithelial connective tissue graft.

BACKGROUND: Various surgical techniques have been proposed for treating gingival recession. This randomized clinical trial compared the coronally positioned flap (CPF) alone or in conjunction with a subepithelial connective tissue graft (SCTG) in the treatment of gingival recession. METHODS: Eleven non-smoking subjects with bilateral and comparable Miller Class I recession defects were selected. The defects, at least 3.0 mm deep, were randomly assigned to the test (CPF + SCTG) or control group (CPF alone). Recession depth (RD), probing depth (PD), clinical attachment level (CAL), width of keratinized tissue (KT), and gingival/mucosal thickness (GT) were assessed at baseline and 6 months postoperatively. RESULTS: Recession depth was significantly reduced 6 months postoperatively (P<0.05) for both groups. Mean root coverage was 75% and 69% in the test and control groups, respectively. There were no significant differences between the two groups in RD, PD, or CAL, either at baseline or at 6 months postoperatively. However, at 6 months postoperatively, the test group showed a statistically significant increase in KT and GT compared to the control group (P<0.05). CONCLUSIONS: The results indicate that both surgical approaches are effective in addressing root coverage. However, when an increase in gingival dimensions (keratinized tissue width, gingival/mucosal thickness) is a desired outcome, then the combined technique (CPF + SCTG) should be used.

Clinical and radiographic evaluation of soft and hard tissue changes around implants: a pilot study.

BACKGROUND: The aim of this study was to evaluate the clinical and radiographic changes in the peri-implant tissues around one-stage implants with different smooth neck portion lengths before and after functional prosthetic loading. METHODS: Twelve one-stage implants were placed in adult patients with bilateral edentulous posterior mandibular ridges. The sites were randomly assigned into two groups of six each: group 1: 2.8 mm neck implants and group 2: neck implants. The parameters plaque index (PI), gingival index (GI), probing depth (PD), gingival margin level (GML), relative clinical attachment level (r-CAL), and optical density (OD) were measured at loading (4 months) and 12 months after implant placement. The radiographic parameter osseous level (OL) was measured at implant placement, loading, and at 12 months. Analysis of variance and the paired Student t test were used to detect difference over time and between groups. RESULTS: The results showed significant differences (P<0.05) for both groups for PD, r-CAL, and OL for intragroup comparisons over time. However, no significant differences were found for PI, GI, PD, GML, OD, and OL for between-group comparisons. CONCLUSION: Bony loss occurred before loading, supporting the soft tissues and maintaining the biologic width irrespective of the smooth portion length.

Root coverage: comparison of coronally positioned flap with and without titanium-reinforced barrier membrane.

BACKGROUND: Various surgical procedures have been proposed as effective treatment methods for recession defects. The purpose of this study was to evaluate the clinical outcome of root coverage comparing the coronally positioned flap (CPF) with and without guided tissue regeneration (GTR) using a titanium-reinforced expanded polytetrafluoroethylene barrier in paired gingival recession defects. METHODS: Procedures were performed in 10 patients having bilateral buccal recession defects > or = 2.0 mm on maxillary canines and first premolars. Mucoperiosteal flaps were raised and root surfaces were scaled, planed, and conditioned. Randomly assigned sites received either GTR + CPF or CPF treatment. Clinical parameters measured at baseline and at 6 months after the procedure included gingival recession depth (GRD), clinical attachment level (CAL), probing depth (PD), keratinized gingival width (KGW), and alveolar crest level (ACL). RESULTS: GRD decreased from 3.4 +/- 0.6 mm to 1.9 +/- 1.2 mm with GTR (45% root coverage) and from 3.3 +/- 0.4 mm to 1.3 +/- 0.7 mm with CPF (60% root coverage). The difference in GRD decrease between procedures was significant. CAL, KGW, and PD differences between procedures were not significant. ACL mean gain was significant (1.0 +/- 0.6 mm in the GTR group and 0.2 +/- 0.3 mm in the CPF group; P < 0.05). CONCLUSIONS: Both GTR and CPF procedures result in root coverage. The amount of root coverage obtained with CPF was greater than that observed with GTR, although GTR resulted in significantly greater ACL gain.

Clinical and radiographic treatment evaluation of class III furcation defects using GTR with and without inorganic bone matrix.

OBJECTIVE: The aim of this study was to evaluate the effect of guided tissue regeneration (GTR) alone and in conjunction with a bovine inorganic bone matrix in furcation defects. MATERIAL AND METHODS: Twenty class III furcation defects were treated in 18 non-smoker patients, 35-75 years old. Horizontal (CAL-H) and vertical clinical attachment levels (CAL-V), probing depths (PD), gingival margin levels (GML), horizontal (BDL-H) and vertical bone defect levels (BDL-V), and alveolar crest levels (ACL) were performed at baseline and at 6-month re-entry procedures. Subtraction radiography was used to assess gain or loss in optical density (OD) and area of bone fill (A) (baseline/6 months). After flap elevation, the sites were randomly assigned to receive GTR + Bio-Oss (test) or GTR treatment alone (control). Results were evaluated using anova. RESULTS: Differences were statistically significant between baseline and re-entry for PD, ACL (p < 0.01) and GML (p < 0.05) for the control group, and for BDL-V (p < 0.01) for the test group. There was a gain in ACL for the test group and a reduction in ACL for the control group (p < 0.01). No differences were observed for OD and A. CONCLUSION: The results of this study indicate that class III furcation defects are not predictably resolved utilizing GTR or GTR in combination with an inorganic bone matrix.

Clinical and radiographic evaluation of periodontal intrabony defects treated with guided tissue regeneration. A pilot study.

BACKGROUND: The aim of this clinical and radiographic study was to evaluate the effect of guided tissue regeneration using a bioabsorbable barrier in the treatment of intrabony defects in humans. METHODS: Intrabony osseous defects (2 or 3 walls) around mandibular canines and premolars were treated in 10 systemically healthy patients with ages ranging from 35 to 56 years. Prior to the surgical phase, patients were enrolled in a strict maintenance program including oral hygiene instructions and scaling and root planing (presurgical Pi and GI < 10%). Patients were seen for professional prophylaxis during the duration of the study. Clinical measurements were performed with an electronic probe at baseline and at reentry 8 months following surgical therapy. Measurements included clinical attachment levels (CAL), gingival margin levels (GML), probing depths (PD), bone defect levels (BDL), and alveolar crest level (ACL). A split mouth design was used. Quadrants were randomly assigned for treatment by GTR (experimental) or open flap debridement alone (control). Standardized radiographs were taken at baseline and at reentry. Digital images were analyzed by subtraction to assess changes in area (A) and optical density (OD). Data were evaluated using paired t test. RESULTS: Statistically significant differences were found in both groups when comparing baseline and post-treatment values for CAL, GML, PD, and BDL (P < 0.0 1). Greater reductions in BDL and gain in A and OD were observed in the GTR group when compared to control (P < 0.01). Both therapies were effective in improving the clinical parameters assessed. CONCLUSION: Clinical and radiographic findings from this study demonstrated more bone fill in sites treated with GTR.

Clinical and Radiographic Evaluation Periodontal Intrabony Defects Treated With Guided Tissue Regeneration. A Pilot Study.

BACKGROUND: The aim of this clinical and radiographic study was to evaluate the effect of guided tissue regeneration using a bioabsorbable barrier in the treatment of intrabony defects in humans. METHODS: Intrabony osseous defects (2 or 3 walls) around mandibular canines and premolars were treated in 10 systemically healthy patients with ages ranging from 35 to 56 years. Prior to the surgical phase, patients were enrolled in a strict maintenance program including oral hygiene instructions and scaling and root planing (presurgical PI and GI <10%). Patients were seen for professional prophylaxis during the duration of the study. Clinical measurements were performed with an electronic probe at baseline and at reentry 8 months following surgical therapy. Measurements included clinical attachment levels (CAL), gingival margin levels (GML), probing depths (PD), bone defect levels (BDL), and alveolar crest level (ACL). A split mouth design was used. Quadrants were randomly assigned for treatment by GTR (experimental) or open flap debridement alone control). Standardized radiographs were taken at baseline and at reentry. Digital images were analyzed by subtraction to assess changes in area (A) and optical density (OD). Data were evaluated using paired t test. RESULTS: Statistically significant differences were found in both groups when comparing baseline and post-treatment values for CAL, GML, PD, and BDL (P <0.01). Greater reductions in BDL and gain in A and OD were observed in the GTR group when compared to control (P <0.01). Both therapies were effective in improving the clinical parameters assessed. CONCLUSION: Clinical and radiographic findings from this study demonstrated more bone fill in sites treated with GTR. J Periodontol 2002;73:353-359.

[Comparison between gingival and periodontal ligament fibroblasts from the same subject]. / Comparação entre fibroblastos gengivais e do ligamento periodontal de um mesmo indivíduo.

The objective of this study was to compare fibroblasts from the periodontal ligament (PLF) and gingival fibroblasts (GF) as to morphology, proliferation rate and protein synthesis. PLF and GF were explanted from tissues of the same patient. To characterize and compare the morphology of cells, PLF and GF were plated and analyzed under phase-contrast and optical microscopies. Proliferation rates were determined by means of automated counts carried out in days 1, 4, 7, 15 and 21, and also by means of the bromodeoxyuridine labelling index (BrdU). Total protein content was analyzed by means of electrophoresis in 10% polyacrylamide gel and zimography containing gelatin as substrate. PLF were bigger and more elongated than GF in subconfluence and confluence conditions. The proliferative rate of PLF was higher than that of GF at 1, 4, and 7 days (p < 0.05). At 15 and 21 days, there was no statistically significant difference as to the number of cells. PLF presented a significantly greater proliferative potential, in relation to GF (p < 0.05). The synthesis of protein in a period of 24 hours was similar for both PLF and GF. Our results demonstrated that PLF and GF are different as to morphology and proliferative capacity, however, they do not differ as to protein synthesis.