Antonio Fernando Martorelli de Lima

Smoking influences on the thickness of marginal gingival epithelium

Smoking patients show reduction of inflammatory clinical signs that might be associated with local vasoconstriction and an increased gingival epithelial thickness. The purpose of this work was to evaluate the thickness of the marginal gingival oral epithelium in smokers and non-smokers, with clinically healthy gingivae or with gingivitis. Twenty biopsies were obtained from four different groups. Group I: non-smokers with clinically healthy gingivae (n = 5). Group II: non-smokers with gingivitis (n = 5). Group III: smokers with clinically healthy gingivae (n = 5). Group IV: smokers with gingivitis (n = 5). These biopsies were histologically processed, serially sectioned at 5 microns, stained with H. E., and examined by image analysis software (KS400), which was used to perform the morphometric evaluation and the quantification of the major epithelial thickness, the epithelial base thickness and the external and internal epithelial perimeters. Differences between the four groups were analyzed using ANOVA test and Tukeys test. The criteria for statistical significance were accepted at the probability level p < 0.05. A greater epithelial thickness was observed in smokers independent of the gingival health situation.

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.

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.

Characteristics of implant surface and implant-abutment gap in two- and one-stage systems

The aim of this study was to evaluate under scanning electron microscopy the characteristics of the implant surface and the gap between the components of two- and one-stage systems. Three two-stage implants coated with RBM and three one-stage implants coated with TPS were selected. In the two-stage implants, the esthetic-cone abutments were adapted and screw tightened with 20 N/cm . In the one stage implants, solid abutments were adapted and torque tightened mechanical frictional with 30 N/cm. The specimens were mounted on stubs and analyzed under scanning electron microscopy. The gap in each implant was measured in four different points and repeated three times. The paired Student-t test was applied to detect the difference in the gap extension. The results showed that no significant differences (P > 0.05) were found regarding the gap extension between two- and one-stage systems and that the treatments produced different surface roughness.

Comparação entre fibroblastos gengivais e do ligamento periodontal de um mesmo indivíduo

O objetivo deste estudo foi comparar as caracteristicas morfologicas, o potencial proliferativo e a producao proteica de fibroblastos do ligamento periodontal (FLP) e de fibroblastos gengivais (FG). Os fibroblastos foram cultivados pela tecnica do explante a partir de fragmentos da gengiva e do ligamento periodontal de um mesmo individuo. As celulas foram isoladas e plaqueadas para analise por microscopia de contraste de fase e microscopia optica. O indice de proliferacao celular foi determinado por contagem automatica de celulas e pelo ensaio de incorporacao de bromodioxiuridina (BrdU). A producao de proteina total foi verificada por eletroforese em gel de poliacrilamida e o perfil enzimatico por analise zimografica. Os FLP sao maiores e mais alongados que os FG em condicoes de subconfluencia e confluencia celular. Os FLP demonstraram um potencial proliferativo significantemente maior que os FG. Os perfis proteico e enzimatico foram similares entre os FLP e FG. Os resultados demonstram que os FLP e FG sao diferentes na morfologia e na capacidade proliferativa, porem sao semelhantes na producao proteica.