Preheated composite resin used as a luting agent for indirect restorations: effects on bond strength and resin-dentin interfaces.

PURPOSE: The aim of this study was to evaluate the effect of preheating composite resins used as luting agents for indirect restorations on microtensile bond strength (µTBS) and adhesive interfaces. MATERIAL AND METHODS: Fifty sound extracted third molars were used. Ten experimental groups were formed with three different luting agents: one resin cement (RelyX ARC) and two composite resins (Venus and Z250 XT). The composite resins were tested both at room temperature and when preheated to 64°C. Restoration depth was tested using 2 or 4 mm-height indirect composite resin restorations, previously made on cylindrical molds. Adhesive and luting procedures were done under simulated pulpal pressure. After luting, the teeth were sectioned into beams with a cross-sectional area of 1 mm2 at the bonded interface, and tested in tension at 0.5 mm/min. The characteristics of the adhesive interfaces were observed under scanning electron microscopy (SEM). The µTBS data were analyzed using ANOVA and the Tukey test (α = 0.05). RESULTS: When luting 2 mm restorations, the composite resin Z250 XT, preheated or at room temperature, achieved significantly higher µTBS than did RelyX ARC. At this depth, Venus did not differ from the resin cement, and with the 4 mm restorations, only preheated Venus presented significantly higher µTBS than RelyX ARC. Preheating the composite resin resulted in thinner luting interfaces, with a more intimate interaction between luting agent and adhesive layer. CONCLUSION: Preheating composite resin for luting procedures may not improve µTBS, although it could be used to reduce material viscosity and improve restoration setting.

Full-mouth ultrasonic debridement associated with povidone iodine rinsing in GAgP treatment: a randomised clinical trial.

OBJECTIVE: This study evaluated the clinical, immunological and microbiological results of full-mouth ultrasonic debridement (FMUD) with 10 % povidone iodine (PVPI) as the cooling liquid in the treatment of generalised aggressive periodontitis (GAgP). MATERIAL AND METHODS: Twenty-eight patients presenting GAgP were randomly assigned to one of the following groups for evaluation: FMUD + SS (n = 14)--single session of FMUD with 0.9 % saline solution as cooling agent and FMUD + PVPI (n = 14)--single session of FMUD with PVPI solution as cooling agent. Probing depth (PD), relative clinical attachment level (RCAL), relative position of gingival margin, plaque index (FMPI) and bleeding score (FMBS), immunological (interleukin-10 and interleukin-1ß concentrations in gingival crevicular fluid) and microbiological (Aa and Pg amounts) parameters were evaluated at baseline, first, third and sixth months after treatment. RESULTS: The two groups presented reduction of FMPI and FMBS and had statistically significant PD reductions, RCAL gains and gingival recession (p < 0.05). Both therapies reduced Pg levels in deep and in moderate pockets (p < 0.05). FMUD + PVPI reduced Aa levels in deep pockets. However, no inter-group differences in clinical, immunological and microbiological parameters were observed (p > 0.05). CONCLUSIONS: It could be concluded that 10 % PVPI used as an irrigant solution in FMUD decreased Aa levels in deep pockets but had no additional benefits when compared with saline solution irrigation in terms of clinical, microbiological and immunological results. CLINICAL RELEVANCE: The FMUD is a valid option for the treatment of GAgP, but the use of 10 % PVPI did not improve the results of the periodontal therapy.

Effect of Fluoride-containing Restorative Materials on Dentin Adhesion and Demineralization of Hard Tissues Adjacent to Restorations.

PURPOSE: This study evaluated (1) the dentin bond strength of fluoridated restorative systems following aging and (2) the enamel/dentin microhardness around restorations after a pH-cycling regimen. MATERIALS AND METHODS: Sixty-four human third molars and four restorative systems were used. A resin-modified glass ionomer (GC Fuji II LC) was used as a fluoride-containing material in the positive control group, while Adper Easy Bond adhesive and Filtek Z350 XT composite resin, which are not fluoridated, were used together in the negative control group. Beautifil II composite resin and FL-Bond II adhesive, both fluoride-containing materials, were compared to Bond Force and Estelite Sigma Quick restorative system, which only contain fluoride in the adhesive. For dentin bond strengths, specimens of each material were fabricated for two test groups (n=8): group 1: tested after 24 h; group 2: tested after 1 year of storage in artificial saliva. Both groups were tested using a microtensile method. For the cross-sectional microhardness test, standardized Class V cavities were prepared and filled with the different restorative systems. After experiencing repeated thermocycling and being subjected to pH-cycling, the teeth were sectioned. The microhardness was measured in enamel and dentin at 50 µm from the cavity wall and at six depths in relation to the surface subjected to pH cycling. RESULTS: None of the restorative systems showed decreased bond strength after storage for one year in artificial saliva. No significant differences in microhardness were observed among the restorative materials on enamel and dentin. CONCLUSION: All the restorative systems evaluated presented stable bond strength after one year of storage. The pH cycling caused a reduction in the superficial enamel microhardness close to the cavity wall. In dentin, the demineralization affected the superficial and sub-surface areas.

Outcome of enamel matrix derivative treatment in the presence of chronic stress: histometric study in rats.

BACKGROUND: Psychologic stress and clinical hypercortisolism have been related to direct effects on bone metabolism. However, there is a lack of information regarding the outcomes of regenerative approaches under the influence of chronic stress (CS). Enamel matrix derivative (EMD) has been used in periodontal regenerative procedures, resulting in improvement of clinical parameters. Thus, the aim of this histomorphometric study is to evaluate the healing of periodontal defects after treatment with EMD under the influence of CS in the rat model. METHODS: Twenty Wistar rats were randomly assigned to two groups; G1: CS (restraint stress for 12 hours/day) (n = 10), and G2: not exposed to CS (n = 10). Fifteen days after initiation of CS, fenestration defects were created at the buccal aspect of the first mandibular molar of all animals from both groups. After the surgeries, the defects of each animal were randomly assigned to two subgroups: non-treated control and treated with EMD. The animals were euthanized 21 days later. RESULTS: G1 showed less bone density (BD) compared to G2. EMD provided an increased defect fill (DF) in G1 and higher BD and new cementum formation (NCF) in both groups. The number of tartrate-resistant acid phosphatase-positive osteoclasts was significantly higher in G1 when compared to G2 and in EMD-treated sites of both groups. CONCLUSIONS: CS may produce a significant detrimental effect on BD. EMD may provide greater DF compared to non-treated control in the presence of CS and increased BD and NCF in the presence or absence of CS.

Evaluation of the effectiveness of a voice training program for teachers.

OBJECTIVES: To investigate the effects of a voice education program to teachers on vocal function exercise and voice hygiene and compare a pre- and post-vocal exercise for the teacher's voice quality. METHODS: A random sample of 102 subjects was divided into two groups: experimental group (29 women and seven men) with vocal hygiene and training exercises and control group (52 women and 14 men) with vocal hygiene. Two sessions were held about voice hygiene for the control group and five sessions for the experimental group, one being with reference to the vocal hygiene habit and four vocal exercise sessions. Acoustic analysis of the vowel [i] was made pre- and post-vocal exercise and for the situations of initial and final evaluation of the educational program. Student t test (paired) and Proc MIXED (repeated measures) were used for analyses with level of significance (α = 0.05). RESULTS: The training exercises, posture and relaxation cervical, decreased the mean of fundamental frequency (f(0)) for men (P = 0.04), and for the phonation, intensity, and frequency exercises, there was a significant increase for f(0) in woman (P = 0.02) and glottal to noise excitation ratio (P = 0.04). There was no statistically significant difference intergroup evaluations after 3 months. The control group presented increased mean voice intensity in the final evaluation (P = 0.01). CONCLUSIONS: Voice training exercises showed a positive and immediate impact on the teacher's quality of voice, but it was not sustained longitudinally, suggesting that actions for this purpose should be continued at schools.

Diabetes mellitus may increase bone loss after occlusal trauma and experimental periodontitis.

BACKGROUND: Diabetes mellitus (DM) involves metabolic changes that can negatively influence periodontal tissues, resulting in more prevalent and severe periodontitis and impaired bone formation. Occlusal trauma (OT) is an injury of the supportive periodontium that results in bone loss. It can be hypothesized that DM would increase bone loss after OT, mainly when associated with periodontitis. Thus, the aim of the present study is to evaluate the influence of DM on bone response in the furcation area of teeth subjected to OT in the presence, or absence, of experimental periodontitis (EP) in the rat model. METHODS: Thirty-two male Wistar rats were assigned to four groups: 1) group 1 (G1): DM+OT+EP (n = 8); 2) group 2 (G2): DM+OT (n = 8); 3) group 3 (G3): OT+EP (n = 8); and 4) group 4 (G4): OT (n = 8). G1 and G2 received a single intraperitoneal injection of streptozotocin (STZ). After 10 days, G1 and G3 were subjected to EP by ligature placement. Fifteen days after the start of EP, OT was induced by the creation of a premature contact. The animals were euthanized 35 days after DM induction. RESULTS: DM enhanced bone loss in the presence of OT combined with EP, but did not increase bone loss in teeth subjected to OT alone. EP caused greater bone loss when associated with OT. CONCLUSION: Within the limits of this animal study, it can be concluded that DM enhances bone loss in the presence of occlusal trauma associated with EP.

Morphology and microtensile bond strength of adhesive systems to in situ-formed caries-affected dentin after the use of a papain-based chemomechanical gel method.

PURPOSE: To evaluate the microtensile bond strength of adhesive systems to caries-affected dentin formed in situ after the use of a papain-based chemomechanical removal method. METHODS: 84 human dentin specimens (5 x 5 x 3 mm) were sterilized and randomly distributed on palatal devices of 14 volunteers. Each palatal device, containing six dentin slabs, was used for 14 days according to a caries induction design involving plaque accumulation and sucrose use. After this, fragments were removed from devices and randomly assigned to two groups according to the caries removal method: (1) Chemomechanical (papain-based gel followed by curette), or (2) Mechanical (curette--control group). Specimens were subdivided into three subgroups according to the adhesive system tested: (SB) a two-step etch-and-rinse (Adper Single Bond 2); (SE) a two-step self-etching adhesive (Clearfil SE Bond) and (TriS) a one-step self-etching adhesive (Clearfil Tri-S Bond) and subsequently restored with microhybrid composite resin. After 24 hours, resin-tooth blocks were sectioned into 0.9 mm thick slabs, with one slab of each block being prepared for adhesive interface analysis by scanning electron microscopy, and the remaining blocks were sectioned into 0.8-mm2 sticks that were subjected to tensile stress (0.5 mm/minute). Data were subjected to two-way ANOVA and Tukey's test at a 5% level of significance. RESULTS: The application of the chemomechanical and mechanical methods to demineralized dentin did not affect the bond strength values. SB and SE adhesives promoted statistically similar and significantly higher bond strength values than the TriS. SEM analysis showed no interference of papain-based gel in the formation of hybrid layer; SB showed the thickest hybrid layer with presence of numerous tags; SE showed an intermediate hybrid layer thickness and quantity of tags and the TriS showed no evidence of tag formation.

Full-mouth ultrasonic debridement associated with amoxicillin and metronidazole in the treatment of severe chronic periodontitis.

BACKGROUND: The purpose of this study was to evaluate the adjunctive clinical, microbiologic, and immunologic effects of the systemic administration of amoxicillin and metronidazole in the full-mouth ultrasonic debridement of patients with severe chronic periodontitis. METHODS: Twenty-five patients presenting at least eight teeth with probing depth (PD) > or =5 mm and bleeding on probing (BOP) were selected and randomly assigned to full-mouth ultrasonic debridement + placebo (control group) or full-mouth ultrasonic debridement + amoxicillin and metronidazole (test group). The clinical outcomes evaluated were visible plaque index, BOP, position of the gingival margin, relative attachment level (RAL), and PD. Real-time polymerase chain reaction (PCR) was used for quantitative analysis of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, and Tannerella forsythia (previously T. forsythensis). The enzyme-linked immunosorbent assay (ELISA) technique permitted the detection of prostaglandin E(2,) interleukin-1beta, and interferon-gamma levels in gingival crevicular fluid. All parameters were evaluated at baseline and at 3 and 6 months post-treatment. RESULTS: At 6 months, the test treatment resulted in lower BOP and an additional reduction (0.83 mm) in PD (P <0.05). Data also showed RAL gain > or =2 mm at 43.52% of sites in control patients compared to 58.03% of sites in test patients (P <0.05). However, both groups had similar mean RAL gain (1.68 and 1.88 mm for the control and test groups, respectively). Real-time PCR and ELISA failed to identify significant differences between the groups. CONCLUSIONS: Both treatments resulted in significant clinical improvements; however, there was a slight, but significantly greater, improvement in BOP and the percentage of sites with PD > or =5 mm exhibiting RAL gain > or =2 mm in the test group. Nevertheless, no improvement in the microbiologic or immunologic outcome was observed with the adjunctive use of systemic amoxicillin and metronidazole.

Determinación del sexo por las medidas lineares de la cara y su importancia pericial / Sex determination by the lineal face measures and its forensic importance

El esqueleto cefálico como un todo, es genéricamente denominado cráneo. Comprende los huesos que envuelven el encéfalo y sus respectivas articulaciones, los huesos que forman la cara, relacionados entre sí, con el sistema respiratorio, digestivo y sensorial. La presente investigación tuvo por objetivo estudiar las características diferenciales entre cráneos pertenecientes a individuos de ambos sexos para el estudio de las siguientes medidas: bi-cigomática, prostion-glabela, prostion-espina nasal anterior y medida bi-temporal. El punto alvolar o Prostion es el pnto más anterior y el más declive del borde alveolar superior. Corresponde al punto mediano situado entre los dos incisivos centrales y superiores. Para la realización de este estudio se utilizaron 200 cráneos con procedencia conocida y absoluta certeza en cuatno al sexo, color de la piel, edad, de individuos adultos, provenientes del Cementerio Inmaculada Concepción de la ciudad de Campinas, estado de Sao Paulo, Brasil. Las medidas (mm de las distancias fueron realizadas con auxilio de paquímetro y goniómetro. Los resultados fueron sometidos a análisis estadístico (regresión logística), verificándose que todas las medidas son dimórficas, estableciéndose una fórmula para la determinación del sexo (X=30,4480 - 0,2461, Bi-cigomético) a la que pertenece el cráneo, de forma práctica y confiable, con un índice de confianza de 82.2 por ciento. Se trata de un método eficiente que puede ser utilizado en la identificación del sexo en evaluaciones futuras, pudiendo ser empleado en los servicios de antropología e institutos médico-legales con alto margen de seguridad. Este estudio posibilitará también la practicidad de un cálculo computarizado (AU)

Determinación del sexo por las medidas lineares de la cara y su importancia pericial / Sex determination by the lineal face measures and its forensic importance

El esqueleto cefálico como un todo, es genéricamente denominado cráneo. Comprende los huesos que envuelven el encéfalo y sus respectivas articulaciones, los huesos que forman la cara, relacionados entre sí, con el sistema respiratorio, digestivo y sensorial. La presente investigación tuvo por objetivo estudiar las características diferenciales entre cráneos pertenecientes a individuos de ambos sexos para el estudio de las siguientes medidas: bi-cigomática, prostion-glabela, prostion-espina nasal anterior y medida bi-temporal. El punto alvolar o Prostion es el pnto más anterior y el más declive del borde alveolar superior. Corresponde al punto mediano situado entre los dos incisivos centrales y superiores. Para la realización de este estudio se utilizaron 200 cráneos con procedencia conocida y absoluta certeza en cuatno al sexo, color de la piel, edad, de individuos adultos, provenientes del Cementerio Inmaculada Concepción de la ciudad de Campinas, estado de Sao Paulo, Brasil. Las medidas (mm de las distancias fueron realizadas con auxilio de paquímetro y goniómetro. Los resultados fueron sometidos a análisis estadístico (regresión logística), verificándose que todas las medidas son dimórficas, estableciéndose una fórmula para la determinación del sexo (X=30,4480 - 0,2461, Bi-cigomético) a la que pertenece el cráneo, de forma práctica y confiable, con un índice de confianza de 82.2 por ciento. Se trata de un método eficiente que puede ser utilizado en la identificación del sexo en evaluaciones futuras, pudiendo ser empleado en los servicios de antropología e institutos médico-legales con alto margen de seguridad. Este estudio posibilitará también la practicidad de un cálculo computarizado