Relationship between the inclination of the coronoid process of the mandible and the electromyographic activity of the temporal muscle in skeletal Class I and II individuals

The aim of this study was to verify the relationship between the inclination of the coronoid process of the mandible, and electromyographic activity of the anterior part of the temporal muscle in skeletal Class I and II individuals. Forty-seven volunteers (mean age 24.5 +/- 3.9 years) were subdivided into two groups, according to angle ANB: Class I (n = 25) and II (n = 22). Two radiographic examinations were performed; one lateral cephalogram to measure angle ANB, and one frontal cephalogram to measure the inclination of the coronoid process. Electromyographic (EMG) examination of the anterior part of the subjects' temporal muscles was performed. Statistical analysis of the data showed that Class II individuals presented lower electromyographic activity of the anterior part of the temporal muscle. Based on the results obtained, it was concluded that the skeletal classes analyzed had no influence on the inclination of the coronoid process. The inclination of the coronoid process was not influenced by the electromyographic activity of the anterior part of the temporal muscle in Class I and II individuals; however, the lower electromyographic activity of the anterior part of the temporal muscle could be influenced by the skeletal class in Class II individuals.     

Cytotoxicity evaluation of four endodontic sealers

This study evaluated in vitro the cytotoxicity of four root canal sealers (Topseal, EndoRez, TubliSeal and Kerr Pulp Canal Sealer E.W.T.) and their effects on reactive oxygen/nitrogen intermediate induction by mouse peritoneal macrophages. Thioglycollate-induced cells were obtained from Swiss mice by peritoneal lavage with 5 mL 10 mM phosphate-buffered saline, washed twice and resuspended (10(6) cells/mL) in appropriate medium for each test. Cytotoxicity was determined by the presence of hydrogen peroxide (H2O2) and nitric oxide (NO) by the peroxidase-dependent oxidation of phenol red and Griess reaction, respectively. Sealer suspensions were obtained in two different concentrations from each material: 18 mg/mL and 9 mg/mL, established according to compatibility parameters following MTT assay. Comparing the sealers, H2O2 release at concentrations of 9 mg/mL and 18 mg/mL was similar: Topseal > positive control (medium + cells + 5 mg/mL zimozan solution) > EndoRez > TubliSeal > Kerr Pulp E.W.T. > negative control (medium + cells). NO release at concentration of 9 mg/mL was: positive control (medium + cells + 10 microg/mL LPS solution) > Topseal > Kerr Pulp E.W.T. > TubliSeal = EndoRez > negative control (medium + cells); at concentration of 18 mg/mL was: positive control > Topseal > Kerr Pulp E.W.T > TubliSeal > EndoRez > negative control. Based on the results, it may be concluded that Topseal presented the highest cytotoxicity among the tested sealers, releasing higher concentrations of NO and H2O2 in macrophage culture.     

Effects of the solvent evaporation technique on the degree of conversion of one-bottle adhesive systems

This study evaluated the effect of four methods of solvent evaporation on the degree of conversion (DC) of seven one-bottle adhesive systems: Excite (EX), ONE-STEP (OS), Optibond Solo Plus (OB), Prime&Bond 2.1 (PB), Prime&Bond NT (NT), Single Bond (SB) and Single Bond Plus (SP) using Fourier Transform Infrared Analysis (FTIR). Adhesive resins were: 1) applied to KBr pellet surfaces and left undisturbed for 30 seconds (condition 1), 2) left undisturbed for 30 seconds and air-dried with an air stream for 10 seconds (condition 2), 3) left undisturbed for 60 seconds (condition 3) and 4) left undisturbed for 60 seconds and air-dried for 10 seconds (condition 4) before curing. FTIR spectra were obtained and the DC was calculated by comparing the ratio of aliphatic/aromatic double carbon bonds before and after light-activation for 10 seconds (XL 3000, 3M). The results of each product were analyzed by one-way repeated measure ANOVA and post-hoc Tukey's test (p<0.05). The DC of PB, NT, OB and SP adhesives was not affected by the four evaporation conditions, while the DC of EX, OS and SB changed according to the evaporation method. The results suggested that the DC of some adhesives was similar regardless of the evaporation method when no water from dentin or rinsing was involved. Other bonding agents showed higher DC after specific conditions of solvent evaporation.     

Microtensile bond strength tests: scanning electron microscopy evaluation of sample integrity before testing

The failure of a certain number of microtensile specimens during their preparation and before loading is a common and undesirable occurrence. This study was aimed at observing, under a scanning electron microscope, enamel and dentin microtensile specimens, in order to find structural faults that might be responsible for their premature failure. In a sample of 80 sticks, none of the specimens was found to be free of defects. These may consist of microcracks in enamel, most often at the periphery of the stick, or in dentin at the level of hybrid layer. Gaps were often seen at the interfaces between the substrates. Voids were sometimes visible within the resin composite thickness. Enamel specimens tended to exhibit more defects than dentin specimens. It is fair to suspect that, because of the brittleness of the tissue, enamel microtensile specimens are intrinsically more prone to failure, thus yielding bond strengths which are not significantly higher than those measured on dentin specimens. This leads one to question the reliability of the microtensile method for testing adhesion on enamel. It seems sensible to develop a method for a quantitative assessment of specimens integrity before loading as a possible predictor for their performance under load.     

Cytotoxic effects and pulpal response caused by a mineral trioxide aggregate formulation and calcium hydroxide

PURPOSE: To evaluate the in vivo pulpal response after pulpotomy with different capping agents. In addition, the in vitro cytotoxic effects of both materials were assessed by applying them on culture of pulp cells. METHODS: For the in vivo test, the coronal pulp of 28 teeth of dogs was mechanically removed and the root pulps were capped with the following dental materials: Group 1: Pro-Root MTA (PRMTA); and Group 2 (control): calcium hydroxide saline paste (CH). After 60 days, the animals were sacrificed and the teeth processed for histological analysis. In the in vitro test, experimental extracts obtained from both capping agents were applied on the cultured MDPC-23 odontoblast-like cells. RESULTS: In the root pulps capped with PRMTA or CH, coagulation necrosis partially replaced by dystrophic calcification as well as tubular dentin matrix laid down by elongated pulp cells was observed. None or mild inflammatory response occurred beneath the capped pulpal wound. Regarding the pulpal response, PRMTA and CH presented no statistical difference. However, the teeth capped CH presented greater healthy pulp loss which resulted in convex shape of the hard barrier than PRMTA. When applied on the cultured cells, it was demonstrated that PRMTA and CH solutions decreased the cell metabolic activity by 9.9% and 29.4%, respectively. CH caused higher cytotoxic effects to the MDPC-23 cells as well as deeper healthy pulp tissue loss than PRMTA. However, similar sequence of healing occurred after pulpotomy with both dental materials.     

Oral manifestations of celiac disease. A case report and review of the literature

Celiac disease is a chronic intestinal disease caused by intolerance to gluten associated with poor digestion and absorption of the majority of nutrients and vitamins, which may affect both developing dentition and oral mucosa. The aim of this study is to make a brief review of the literature about celiac disease and to report on a clinical case, showing the impact it may have on the general and oral health. A 39-year-old woman reported the presence of diarrhea, nauseas, flatulence, colic, difficulty with falling asleep, lack of appetite and loose of 18 Kg in the last two years. She also noted the appearance of symptomatic lesions in the mouth. These lesions had a mean duration of a month and occurred in any region of the oral mucosa, particularly on the tongue. Multiples ulcerations were found in the sublingual caruncula region, at the vestibular fornix and at the lingual apex. Topical treatment was instituted for the oral lesions with immediately relief of the symptoms. The diagnosis of celiac disease was established by means of medical clinical exam, biopsy of the small intestine, and by the presence of specific antibodies in the blood. The patient has been instructed to follow a gluten-free diet. Multiprofessional action with the involvement of a gastroenterologist and other health professionals, such as dentists, is important for diagnosing the disease and guiding the patient with celiac disease to achieve a good quality of life.