Resumo em Inglês:

During clinical practice, when performing prosthetic rehabilitation with single crowns, improper reproduction of the dental contour by the dental laboratory is a common occurrence. Therefore, the present study evaluated the fidelity of the reproduction of the buccal contour in an upper left canine performed by three Dental Prosthesis Technicians (DPT) using the indirect laminate veneer technique. First, the DPTs confected the veneers based on a model obtained from the upper arch of a dental dummy, containing a replica of an upper left canine with a prosthetic preparation for a laminate veneer. Then, the same DPTs received other identical models, now with the replica of the upper left canine with no preparation, to be used as an anatomical reference for confecting the laminate veneers. The laminate veneers were then bonded to the plaster models and had their buccal contour individually measured. Measurements were also made of the buccal contour of the reference canine. The data were analyzed by ANOVA and the t-test (p = 0.05). Results showed 100% of buccal overcontour when the laminate veneers were compared to the reference canine, regardless of which DPT confected the veneer and regardless of using or not the anatomical reference. The DPTs who participated in the present study were unable to acomplish a faithful anatomical reproduction of the buccal contour, creating an overcontour in all samples. This situation may be responsible for increasing the probability of periodontal and esthetic harm in clinical practice.

Resumo em Inglês:

The objective of this study was to compare the flexural strength and elasticity modulus of two types of staple reinforcement fibers, Interlig - Ângelus®/glass (Londrina, PR, Brazil) and Connect - KerrLab®/polyethylene (MFG Co., West Collins Orange, CA, USA), which are widely used in Dentistry for chairside use, after varying the number of layers employed and submitting or not to thermocycling. This study was performed on 72 specimens, divided into 8 groups: G1 - single layer of Interlig fibers without thermocycling; G2 - double layer of Interlig fibers without thermocycling; G3 - single layer of Interlig fibers with thermocycling; and G4 - double layer of Interlig fibers with thermocycling; G5 - single layer of Connect fibers without termocycling; G6 - double layer of Connect fibers without termocycling; G7 - single layer of Connect fibers with termocycling; G8 - double layer of Connect fibers with termocycling. For each group, values for flexural strength and elasticity modulus were obtained. The polyethylene fiber employed in a double layer presented the highest flexural strength (p < 0.05), independently of thermocycling (p < 0.001), when compared to the other evaluated combinations. The polyethylene fiber, used in a single layer without thermocycling, demonstrated a significantly higher elasticity modulus, when compared to the other groups (p < 0.05). Within the limits of this study, it was concluded that the polyethylene fiber in a double layer appears to be more resistant, regardless of whether it was submitted to thermocycling or not.

Resumo em Inglês:

The purpose of this study was to evaluate the flexural strength of a direct composite, for indirect application, that received heat treatment, with or without investment. One indirect composite was used for comparison. For determination of the heat treatment temperature, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed, considering the initial weight loss temperature and glass transition temperature (Tg). Then, after photoactivation (600 mW/cm² - 40 s), the specimens (10 x 2 x 2 mm) were heat-treated following these conditions: 170ºC for 5, 10 or 15 min, embedded or not embedded in investment. Flexural strength was assessed as a means to evaluate the influence of different heat treatment periods and investment embedding on mechanical properties. The data were analyzed by ANOVA and Tukey's test (α = 0.05). TGA showed an initial weight loss temperature of 180ºC and DSC showed a Tg value of 157°C. Heat treatment was conducted in an oven (Flli Manfredi, Italy), after 37°C storage for 48 h. Flexural strength was evaluated after 120 h at 37°C storage. The results showed that different periods and investment embedding presented similar statistical values. Nevertheless, the direct composite resin with treatments presented higher values (178.7 MPa) compared to the indirect composite resin (146.0 MPa) and the same direct composite submitted to photoactivation only (151.7 MPa). Within the limitations of this study, it could be concluded that the heat treatment increased the flexural strength of the direct composite studied, leading to higher mechanical strength compared to the indirect composite.

Resumo em Inglês:

In the light of the scarcity of epidemiological studies on the oral health of the general population within the context of the Amazon region, this study aimed to estimate the prevalence of dental caries and gingivitis, as well as to evaluate the need for restorative treatment, among school students aged 15 to 19 years in the city of Manaus, AM, Brazil. A cross-sectional study was carried out on a sample of 889 students from within city limits who were enrolled in 26 public and private schools. Dental examinations were performed to obtain the DMFT index (decayed, missing and filled teeth) as well as to determine the treatments needed. The gingival index (Lõe & Silness) was used to classify gingivitis. The intra-examiner diagnostic concordance was 94% and the Kappa statistic was 0.91. The DMFT index found was 4.65 (± 0.12), without significant difference between the sexes or skin color groups. The prevalence of dental caries was 87.4%. Restoration of a dental surface was the greatest need (59.3%). Slight gingival inflammation was present in 78.5% and gingival bleeding following probing occurred in 53.3%. Although the DMFT index was lower than that observed for the northern region of Brazil, restorative dental services are lacking for this population. Additional studies are suggested to better understand the differences found.

Resumo em Inglês:

Resazurin dye has been broadly used as indicator of cell viability in several types of assays for evaluation of the biocompatibility of medical and dental materials. Mitochondrial enzymes, as carriers of diaphorase activities, are probably responsible for the transference of electrons from NADPH + H+ to resazurin, which is reduced to resorufin. The level of reduction can be quantified by spectrophotometers since resazurin exhibits an absorption peak at 600 ηm and resorufin at 570 ηm wavelengths. However, the requirement of a spectrophotometer and specific filters for the quantification could be a barrier to many laboratories. Digital cameras containing red, green and blue filters, which allow the capture of red (600 to 700 ηm) and green (500 to 600 ηm) light wavelengths in ranges bordering on resazurin and resorufin absorption bands, could be used as an alternative method for the assessment of resazurin and resorufin concentrations. Thus, our aim was to develop a simple, cheap and precise method based on a digital CCD camera to measure the reduction of resazurin. We compared the capability of the CCD-based method to distinguish different concentrations of L929 and normal Human buccal fibroblast cell lines with that of a conventional microplate reader. The correlation was analyzed through the Pearson coefficient. The results showed a strong association between the measurements of the method developed here and those made with the microplate reader (r² = 0.996; p < 0.01) and with the cellular concentrations (r² = 0.965; p < 0.01). We concluded that the developed Colorimetric Quantification System based on CCD Images allowed rapid assessment of the cultured cell concentrations with simple equipment at a reduced cost.

Resumo em Inglês:

Prosthetic eyes are artificial substitutes for the eyeball, made of heat-curing acrylic resin, serving to improve the esthetic appearance of the mutilated patient and his/her inclusion in society. The aim of this study was to assess the flexural strength of two heat-curing acrylic resins used for manufacturing prosthetic eyes. Thirty-six specimens measuring 64 x 10 x 3.3 mm were obtained and divided into four groups: acrylic resin for artificial sclera N1 (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GI) and microwave-cured (GII); colorless acrylic resin for prosthetic eyes (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GIII) and microwave-cured (GIV). Mechanical tests using three point loads were performed in a test machine (EMIC, São José dos Pinhais, PR, Brazil). The analysis of variance and the Tukey test were used to identify significant differences (p < 0.01). Groups GII and GIV presented, respectively, the highest (98.70 ± 11.90 MPa) and lowest means (71.07 ± 8.93 MPa), with a statistically significant difference. The cure method used for the prosthetic eye resins did not interfere in their flexural strength. It was concluded that all the resins assessed presented sufficient flexural strength values to be recommended for the manufacture of prosthetic eyes.

Resumo em Inglês:

A retrospective study was performed to assess maxillofacial fractures in patients treated at a public hospital from 2002 to 2006. The data collected included age, gender, etiology, type of injury, treatment modalities and period of treatment. Causes were grouped into seven categories: road traffic collisions, sports accidents, occupational accidents, gunshot fractures, falls, violence and other causes. The analyses involved descriptive statistics, the Chi-squared Test and the Fisher Exact Test. Records from 132 patients sustaining 185 maxillofacial fractures were evaluated. The mandible (54.6%) was the most commonly fractured bone in the facial skeleton, followed by the zygoma (27.6%). The mean age of the patients was 37.7 years, and the male:female ratio was 4.3:1. Most fractures occurred in adults with ages ranging from 18 to 39 years. A significant statistical relation was found between the age and the etiology of the trauma (p < 0.05), and between the number of fractured sites and the age of the patient (p < 0.05). Considering the age groups, accidents were the most frequent cause of maxillofacial fractures in the age group between 18 to 39 years, and interpersonal violence was the most frequent cause of maxillofacial fractures in the age group between 40 to 59 years. Treatment was performed on the same day as the diagnosis in 44.7% of the patients. Open surgery with internal stable fixation was indicated for most of the patients. Facial fractures occurred primarily among men under 30 years of age, and the most common sites of fractures in the face were the mandible and the zygomatic complex. Traffic road collisions were the main etiologic factor associated with maxillofacial trauma.

Resumo em Inglês:

A radiographic and histomorphometric study was conducted on the influence of autologous plasma rich in growth factors (PRGF) upon bone healing in surgically created defects in rabbits. Radiographically, bone regeneration was significantly greater with the use of PRGF after one month (p = 0.005), though no differences were recorded after the second month. In the histomorphometric analysis one month after surgery, the defects filled with autologous bone plus PRGF showed a greater percentage of neoformed bone (35.01 ± 5.31) than the control defects (22.90 ± 12.23), though the differences were not significant. Two months after surgery, the defects filled with autologous bone showed greater regeneration (46.04 ± 10.36%) than the control defects (30.59 ± 5.69%), though the differences were not significant. The application of PRGF in the bone defects produced in New Zealand rabbits exerted a limited effect on local bone formation.

Resumo em Inglês:

The aim of this study was to evaluate the occurence of compensation in mesiodistal axial inclinations of canines in skeletal malocclusions patients. The sample consisted of 25 Angle Class II, division 1 malocclusion (group 1) and 19 Angle Class III malocclusion patients (group 2). After measurement of dental angulations through a method that associates plaster model photography and AutoCad software, comparisons between the groups were performed by T-test for independent samples. Results showed that there was no statistically significant difference (p < 0.05) between groups, when maxillary canine angulations were compared. Regarding the mandibular canines, there was a statistically significant difference in dental angulation, expressed by 3.2° for group 1 and 0.15° for group 2. An upright position tendency for mandibular canines was observed in the Angle Class III sample. This configures a pattern of compensatory coronary positioning, since the angulation of these teeth makes them occupy less space in the dental arch and consequently mandibular incisors can be in a more retracted position in the sagittal plane.

Resumo em Inglês:

The aim of this study was to determine the reproducibility, reliability and validity of measurements in digital models compared to plaster models. Fifteen pairs of plaster models were obtained from orthodontic patients with permanent dentition before treatment. These were digitized to be evaluated with the program Cécile3 v2.554.2 beta. Two examiners measured three times the mesiodistal width of all the teeth present, intercanine, interpremolar and intermolar distances, overjet and overbite. The plaster models were measured using a digital vernier. The t-Student test for paired samples and interclass correlation coefficient (ICC) were used for statistical analysis. The ICC of the digital models were 0.84 ± 0.15 (intra-examiner) and 0.80 ± 0.19 (inter-examiner). The average mean difference of the digital models was 0.23 ± 0.14 and 0.24 ± 0.11 for each examiner, respectively. When the two types of measurements were compared, the values obtained from the digital models were lower than those obtained from the plaster models (p < 0.05), although the differences were considered clinically insignificant (differences < 0.1 mm). The Cécile digital models are a clinically acceptable alternative for use in Orthodontics.

Resumo em Inglês:

The purpose of this study was to evaluate the effect of the application of fluoride products on the development of enamel caries in deciduous teeth. A total of 108 deciduous teeth were chosen for the study. Acid-resistant varnish was applied on the teeth, leaving only one area of 5 mm x 1 mm of dental enamel exposed. The teeth were allocated randomly to one of the following groups: 1) control - toothpaste without fluoride; 2) 1.23% fluoride gel; 3) Duraflur fluoride varnish; 4) Duraphat fluoride varnish; 5) Fluorniz fluoride varnish; 6) Fluorphat fluoride varnish; 7) varnish with Duofluorid; 8) 12% silver fluoride diamine (Cariestop); 9) children's fluoride toothpaste (500 ppm). The tested products were applied on the teeth according to the manufacturer's recommendations and the teeth were stored in a moist environment for 24 hours. Each group of teeth was then subjected to a pH cycling model for 14 days, after which the teeth were cut through the center for an analysis of the depth of the carious lesion by polarized light microscopy. Comparisons were made between the treatments and the control group. The mean lesion depth values were 318 μm ± 39 (control), 213 μm ± 27 (fluoride gel), 203 μm ± 34 (Duraflur), 133 μm ± 25 (Duraphat), 207 μm ± 27 (Fluor-niz), 212 μm ± 27 (Fluorphat), 210 ± 28 (Duofluorid), 146 ± 31 (Cariestop) and 228 ± 24 (fluoride toothpaste). None of the products used here was able to completely prevent the formation of lesions. The highest cariostatic effect was achieved by fluoride varnish Duraphat and the lowest by the fluoride toothpaste.

Resumo em Inglês:

"When" and "how" the dentist intervenes have repercussions on children's physical and emotional patterns. The objective of the present study was to conduct a longitudinal behavioral analysis during dental care of babies aged 0 to 3 years. A total of 216 patients seen at the Baby Clinic of the School of Dentistry at Araçatuba, São Paulo State University (UNESP), were selected. The selection criterion was attendance at ten dental care sessions at bimonthly intervals for routine procedures such as clinical examination and oral hygiene. There was a predominance of cooperative behavior compared to uncooperative behavior when each visit was analyzed separately. The behavior of the patients must have been directly influenced by their psychomotor development. Constant attendance and exposure of the baby to non-stressful dental stimuli are factors that favor a cooperative behavior.

Resumo em Inglês:

In a previous study, we evaluated the findings related to the use of resorbable collagen membranes in humans along with DFDBA (demineralized freeze-dried bone allograft). The aim of this subsequent study was to histometrically evaluate in dogs, the healing response of gingival recessions treated with collagen membrane + DFDBA (Guided Tissue Regeneration, GTR) compared to a coronally positioned flap (CPF). Two types of treatment were randomly carried out in a split-mouth study. Group 1 was considered as test (GTR: collagen membrane + DFDBA), whereas Group 2 stood for the control (only CPF). The dogs were given chemical bacterial plaque control with 0.2% chlorhexidine digluconate during a 90-day repair period. Afterwards, the animals were killed to obtain biopsies and histometric evaluation of the process of cementum and bone formation, epithelial migration and gingival level. A statistically significant difference was found between groups with a larger extension of neoformed cementum (GTR = 32.72%; CPF = 18.82%; p = 0.0004), new bone (GTR = 23.20%; CPF = 09.90%; p = 0.0401) and with a smaller area of residual gingival recession in the test group (GTR = 50.69%; CPF = 59.73%; p = 0.0055) compared to the control group. The only item assessed that showed no statistical difference was epithelial proliferation on the root surface, with means of 15.14% for the GTR group and 20.34% for the CPF group (p = 0.0890). Within the limits of this study we concluded that the treatment of gingival recession defects with GTR, associating collagen membrane with DFDBA, showed better outcomes in terms of a larger extension of neoformed cementum and bone, as well as in terms of a smaller proportion of residual recessions.

Resumo em Inglês:

Knowledge about the presence of some important oral pathogens is an important step in better identifying children at risk for periodontal and/or caries diseases in later life. The purpose of this study was to detect the presence of Streptococcus mutans (Sm), Aggregatibacter actinomycetemcomitans (Aa), Campylobacter rectus (Cr), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Tannerella forsythia (Tf) in gingival biofilm samples from 196 children, and to assess whether any of these pathogens are more associated with gingival inflammation extension and the Decayed/Missing/Filled teeth (DMFT/dmft) index. The subjects presented plaque index greater than 80% and were divided in 3 groups according to the bleeding index (BI): I) Low bleeding (< 30%), II) Medium bleeding (31 - 59%) and III) High bleeding (> 60%). The presence of each pathogen was determined by PCR. The prevalence of Sm was 71.9% and the mean dmft/DMFT was 6.68. The prevalence in low, medium and high bleeding groups was 43.5%, 34.5% and 46.7% for Aa; 43.5%, 37.9%, and 36.7% for Cr; 99.1%, 100%, and 96.7% for Pg; 56.5%, 56.9%, and 66.7% for Pi; and 58.3%, 60.3%, and 56.7% for Tf, respectively. Pg (99.0%) was the most prevalent periodontal pathogen detected followed by Tf (58.7%), Pi (58.2%), Aa (41.3%) and Cr (40.8%). Our study indicated that in this high plaque index population studied, a high prevalence of Sm and high mean DMFT were observed. In addition, the presence of Pi was associated with the presence of inflammation (P < 0.05) whereas Cr was associated with periodontal health (P < 0.05).

Resumo em Inglês:

The objective of this randomized, examiner blind, parallel group, controlled clinical trial was to compare the antiplaque and antigingivitis efficacy of an essential oil-containing mouthrinse (EO) to two mouthrinses containing 0.05% Cetylpyridinium Chloride (CPC), one with alcohol and one alcohol-free, using a two-week experimental gingivitis validated-model with a 5% hydroalcohol rinse serving as the negative control. One hundred and fifty-nine subjects, 56 males and 103 females; ranging in age from 18 to 58 years in good general health were assigned to one of the four treatment groups: EO (n = 40), 0.05% CPC with alcohol (CPCa, n = 39), 0.05% CPC alcohol-free (CPCna, n = 40), and 5% hydroalcohol negative control (n = 40). The Mean Turesky Modification of the Quigley-Hein Plaque Index (PI) and the Mean Modified Gingival Index (MGI) were the primary efficacy endpoints and were evaluated at baseline and at two weeks. Following baseline examinations, subjects received a complete dental prophylaxis and began supervised rinsing with their assigned mouthrinse twice daily for two weeks, as their sole oral hygiene measure; 151 subjects completed the trial. Two weeks after baseline the EO adjusted mean PI and MGI scores were significantly lower than those of both CPC rinses and negative control (p < 0.001). In conclusion, the EO mouthrinse demonstrated significantly greater antiplaque and antigingivitis efficacy than both CPC-containing mouthrinses and the negative control.

Resumo em Inglês:

Alcohol consumption is a risk indicator for periodontal disease. The purpose of this study was to morphometrically evaluate the influence of alcohol consumption on alveolar bone level associated with ligature-induced periodontitis in rats. Thirty-six female rats (Wistar, 120 days-old) were randomly divided into three groups that received a daily administration of a water diet (control, n = 12), a 10% alcohol diet (10% ethanol, n = 12) or a 20% alcohol diet (20% ethanol, n = 12). Four weeks after the onset of the experiment, cotton ligatures were placed around the cervix of the upper right second molar in six rats. The other 6 rats in each group remained unligated. The rats were sacrificed four weeks after ligature placement. The maxillary bones were removed and alveolar bone loss was analyzed by measuring the distance between the cementoenamel junction and the alveolar bone crest at 2 buccal and 2 palatal sites on the upper right second molar. Analyses between the ligated and unligated groups showed that the presence of ligature induced alveolar bone loss (p < 0.05). Unligated groups showed no significant differences between each other (p > 0.05). In the ligated groups, rats receiving 20% ethanol showed significantly greater bone loss compared to control rats or rats receiving 10% ethanol. These results demonstrate that alcohol consumption may increase alveolar bone loss in female rats in a dose-dependent manner.

Resumo em Inglês:

The aim of this study was to compare different treatments for dentin hypersensitivity in a 6-month follow-up. One hundred and one teeth exhibiting non carious cervical lesions were selected. The assessment method used to quantify sensitivity was the cold air syringe, recorded by the visual analogue scale (VAS), prior to treatment (baseline), immediately after topical treatment, after 1 week, 1, 3 and 6 months. Teeth were randomly assigned to five groups (n = 20): G1: Gluma Desensitizer (GD); G2: Seal&Protect (SP); G3: Oxa-gel (OG); G4: Fluoride (F); G5: Low intensity laser-LILT (660 nm/3.8 J/cm²/15 mW). Analysis was based on the non-parametric Kruskal-Wallis test that demonstrated statistical differences immediately after the treatment (p = 0.0165). To observe the individual effects of each treatment, data was submitted to Friedman test. It was observed that GD and SP showed immediate effect after application. Reduction in the pain level throughout the six-month follow-up was also observed. In contrast, LILT presented a gradual reduction of hypersensitivity. OG and F showed effects as of the first and third month respectively. It can be concluded that, after the 6-month clinical evaluation, all therapies showed lower VAS sensitivity values compared with baseline, independently of their different modes of action.

Resumo em Inglês:

The purpose of this study was to investigate the influence of chlorhexidine (CHX) concentration on the microtensile bond strength (μTBS) of contemporary adhesive systems. Eighty bovine central incisors were used in this study. The facial enamel surface of the crowns was abraded with 600-grit silicon carbide paper to expose flat, mid-coronal dentin surfaces. The tested materials were Scotchbond Multipurpose (SMP), Single-Bond (SB), Clearfil SE Bond (CSEB) and Clearfil Tri S Bond (CTSB). All the materials were applied according to manufacturer's instructions and followed by composite application (Z250). The teeth were randomly divided into 16 groups: for the etch-and-rinse adhesives (SMP and SB), 0.12% or 2% CHX was applied prior to or after the acid etching procedure. For the self-etch adhesives (CSEB and CTSB) 0.12% or 2% CHX was applied prior to the primer. Control groups for each one of the adhesive systems were also set up. The specimens were immediately submitted to μTBS testing and the data were analyzed using Analysis of Variance and the Tukey post hoc test (alpha = .01). The failure patterns of the specimens were observed using scanning electron microscopy. The effects of 2% CHX were statistically significant (p < 0.01) for the self-etch adhesives but were not significant for the etch-and-rinse adhesive systems. Analysis of the data demonstrated no statistical difference between the etch-and-rinse adhesive systems. CHX-based cavity disinfectants in concentrations higher than 0.12% should be avoided prior to the self-etch adhesive systems evaluated in this study to diminish the possibilities of reduction in bond strength.

Resumo em Inglês:

The aim of this work was to present a small cross-sectional survey of composite restoration clinical attributes associated with choices for replacement. Ninety-four composite fillings selected to be replaced were included in this study. A questionnaire was filled out after each procedure in order to assess the clinical conditions that indicated the restoration replacement (marginal staining, unsatisfactory restoration anatomy, marginal fracture, fractured restoration body, painful symptoms, dental fracture, composite discoloration and/or restoration displacement). These conditions could be combined. The chi-square and Exact Fisher tests were performed to analyze the different variables (p < 0.05). The results showed that composite shade discoloration was the main cause of restoration replacement (63.8%). Marginal staining (50%), unsatisfactory restoration anatomy (50%), marginal fracture (14.9%), painful symptoms (8.5%), fractured restoration body (4.3%), dental fracture (1.1%) and total displacement of the restoration (1.1%) were conditions that could be associated. The main cause of dental composite restoration replacement was material shade mismatch with the dental structure (anterior teeth) or marginal staining and unsatisfactory restoration shape (posterior teeth). Marginal staining and composite shade discoloration contrasting with dental structure were related to the presence of caries.