Vol 9, No 3 (2012)
Proceeding Abstracts
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Accurate prediction of the surgical outcome is important in treating dentofacial deformities. Visualized treatment objectives usually involve manual surgical simulation based on tracing of cephalometric radiographs. Recent technical advancements have led to the use of computer assisted imaging systems in treatment planning for orthognathic surgical cases. The purpose of this study was to examine and compare the ability and reliability of digitization using Dolphin Imaging Software with traditional manual techniques and to compare orthognathic prediction with actual outcomes.Forty patients consisting of 35 women and 5 men (32 class III and 8 class II) with no previous surgery were evaluated by manual tracing and indirect digitization using Dolphin Imaging Software. Reliability of each method was assessed then the two techniques were compared using paired t test.The nasal tip presented the least predicted error and higher reliability. The least accurate regions in vertical plane were subnasal and upper lip, and subnasal and pogonion in horizontal plane. There were no statistically significant differences between the predictions of groups with and without genioplasty.Computer-generated image prediction was suitable for patient education and communication. However, efforts are still needed to improve accuracy and reliability of the prediction program and to include changes in soft tissue tension and muscle strain.
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To evaluate the influence of core thickness and fabrication stages on the marginal accuracy of IPS e.max Press crowns.Twenty IPS e.max Press crowns, 1.5mm thick, were fabricated on metal dies. The crowns had two different core thicknesses, 0.8mm for group A and 1mm for group B, ten for each group. Marginal gap was measured after each stage of core fabrication, veneering and glaze firing. The specimens were not cemented and the measurements were made at four points on metal dies using a stereomicroscope (×120). Data were analyzed by SPSS software and independent t-test.Mean marginal gaps measured after each stage for group A were 13.5 (±1.4) μm, 33.9 (±2.3) μm and 40.5(±1.7) μm, and for group B these figures were 14.9(±2.0) μm, 35.5(±2.2) μm and 41.3(±2.0) μm. There were no statistically significant differences in marginal gap values between the two groups (p>0.1). Significant increase in gap was observed after the veneering stage in both groups (p<0.05). After glazing, no significant increase in gap was detected.IPS e.max Press crowns have an acceptable marginal fit. Increasing thickness of core does not increase marginal fitness.
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The aim of the present study was to examine the periodontal condition of an adult population in three isolated regions in Greece and to determine the association of periodontal disease with several demographic, behavioral and environmental factors.The study population consisted of 640 individuals, aged 20 to 69 years from three isolated regions. The following indices were assessed: Pocket Depth (PD), Clinical Attachment Level (CAL), Dental Plaque, Calculus and Bleeding on Probing (BOP). Statistical analysis was accomplished by multiple linear regression model which was used to assess the association between the mean clinical attachment loss and clinical, demographic and behavioral parameters.The samples of the study showed high levels of dental plaque, dental calculus and BOP. The final multivariate model showed that age (p=0.000), gender (p=0.016) and presence of calculus (p=0.000) were associated with the mean clinical attachment loss. Age (p=0.000), gender (p=0.000) and dental plaque (p=0.027) were associated with gingival recession, while age (p=0.018) and gender (p=0.000) were associated with probing depth. Bleeding on probing, dental plaque, toothbrush frequency, level of education, tobacco consumption and reasons for dental visits were not associated with the mean clinical attachment loss.Periodontal disease consists of a complicated destructive condition of the Periodontal tissue with a. multi-factorial etiology. Oral hygiene instructions and a regular dental follow-up could play a significant role in the prevention of periodontal disease.
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There are various risk factors which play an essential role in the multifactorial disease "dental caries." Although absence of interdental spaces in the primary dentition may increase the risk of dental caries, not many studies have been carried out to assess this correlation. This study was performed to assess the relationship between interdental spacing and dental caries in primary dentition.Five hundred 4-6 year-old children were enrolled into this study. Dental caries was recorded using the criteria given by Warren et al. Following this, impressions were made for the upper and lower arches and dental casts were poured. Interdental spaces were measured on the dental casts using a digital verniercaliper. The data obtained were subjected to statistical analysis.The number of sites with interdental spaces was higher in the maxillary arch in comparison to the mandibular arch. The highest number of interdental spaces was observed between the maxillary anteriors. The number of demineralized, but non-cavitated tooth surfaces (d(1))were higher than the number of cavitated tooth surfaces. This difference was significant in the mandibular anterior segment. Dental caries showed a negative correlation with interdental spacing. A significant correlation was found between dental caries and interdental spacing in the posterior segment of the mandibular arch.This study showed that children with no interdental spacing in the primary dentition are at higher risk for dental caries.
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One of the main criteria in evaluating the restorative materials is the degree of microleakage. The aim of this study was to compare the microleakage of glass ionomer restored cavities prepared by Er:YAG laser or turbine and bur.Twenty extracted caries-free deciduous posterior teeth were selected for this study. The teeth were randomly divided into two groups for cavity preparation. Cavities in group one were prepared by high speed turbine and bur. In the second group, Er:YAG laser with a 3W output power, 300 mJ energy and 10 Hz frequency was used. Cavities were restored with GC Fuji II LC. After thermocycling, the samples were immersed into 0.5% methylene blue solution. They were sectioned for examination under optic microscope.The Wilcoxon signed ranks test showed no significant difference between microleakage of the laser group and the conventional group (P>0.05).Er:YAG laser with its advantages in pediatric dentistry may be suggested as an alternative device for cavity preparation.
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Prolonged excessive intake of fluoride during child's growth and development stages has been associated with mental and physical problems. The aim of this study was to investigate the effect of excessive fluoride intake on the intelligence quotient (IQ) of children living in five rural areas in Makoo/Iran.In this cross-sectional study, 293 children aged 6-11 years were selected from five villages in Makoo with normal fluoride (0.8±0.3 ppm), medium fluoride (3.1±0.9 ppm) and high fluoride (5.2±1.1 ppm) in their water supplies. The IQ of each child was measured by the Raven's test. Educational and residential information and the medical history of each child was recorded by a questionnaire completed by the parents. Data were analyzed by ANOVA test with a significance level of 0.05.The mean IQ scores decreased from 97.77±18.91 for the normal fluoride group to 89.03±12.99 for the medium fluoride group and to 88.58±16.01 for the high fluoride group (P=0.001).Children residing in areas with higher than normal water fluoride levels demonstrated more impaired development of intelligence. Thus, children's intelligence may be affected by high water fluoride levels.
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The purpose of this study was to assess the in vitro effect of ascorbic acid on the antibacterial substantivity of Tetraclean in bovine root dentin pretreated with sodium hypochlorite (NaOCl).Eighty dentin tubes prepared from bovine incisor teeth were infected with Enterococcus faecalis for 14 days. The specimens were divided into five groups as follows: Tetraclean; 5.25% NaOCl/Tetraclean; 5.25% NaOCl/ascorbic acid/Tetraclean; infected dentin tubes (positive control); and sterile dentin tubes (negative control). At experimental times of 0, 7, 14, 21 and 28 days, dentin chips were removed from the canals by sequential sterile low-speed round burs with increasing diameters of 025, 027, 029, 031 and 033 ISO sizes, respectively. After culturing, the number of colony-forming units (CFU) was counted.In all experimental groups, the number of CFU was minimum in the first cultures and the results obtained were significantly different at any time period (p < 0.05). The Tetraclean group showed the most effective antibacterial action at all five experimental periods (p < 0.05). NaOCl/Tetraclean group showed the least antibacterial activity at all time periods. The NaOCl/ascorbic acid/Tetraclean group showed similar antibacterial substantivity to the Tetraclean group at all time periods (p> 0.05).Ascorbic acid prevents the decrease of residual antibacterial activity of Tetraclean in dentin samples pretreated with NaOCl.
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The aim of this study was to compare the lateral window and osteotome techniques for sinus lifting using histological and histomorphometric methods.In this clinical trial 10 patients (a total number of 14 sinus areas) who needed implant treatment in the atrophic posterior maxilla were enrolled. In all the cases the residual bone height between the sinus floor and the alveolar crest was less than 5 mm. Sinus augmentation was performed. The treatment modality for a given residual bone height was selected randomly and Bio-Oss was applied in all the cases as the graft material. After a healing period of about 10 months, in all the cases, the implants were placed and biopsies of alveolar crestal bone were obtained at the same time; biopsy specimens were evaluated using histological and histomorphometric methods. Fisher's exact and Mann-Whitney U tests were used to compare distribution of variables in the two groups. Statistical significance was defined at P<0.05.The new bone was located in direct contact with the biomaterial without any gaps. This viable bone consisted of lacunae containing osteocytes. Infiltration of inflammatory cells did not exhibit any significant differences between the two techniques. Foreign body reaction was not observed in any cases. Histomorphometric evaluations demonstrated that The mean values of the new bone in the lateral window and osteotome techniques were 30±6.0 and 25.2±5.2, respectively, with no significant differences between the two groups.. Moreover, the average quantity of residual biomaterial and connective tissue were similar for the two groups.The nature and the volume of the new bone in lateral window and osteotome techniques were the same.
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Malocclusion is a common oral disorder, can cause negative impacts on oral conditions, social life and patients' self confidence. The objective of this study was to determine whether orthodontic treatment influence oral health related quality of life (OHQoL).Cross-sectional design with self-reported data were collected from 302 participants attended at professional orthodontic office (62% female; mean age, 21.71 years) in two "treatment" and "no treatment" groups. The measure namely (oral health impact profile) OHIP-14 was used to assess the patient's OHQol. Linear regression model was used in the data analysis.A significant relationship was found in one question and one domain of OHIP-14 between the two groups (P<0.05) which showed difference in physical limitation. Linear regression model showed that in the treatment group, this domain of OHQoL was 1.86 times less likely complicated than in the "no treatment" group.Patients who had completed orthodontic treatment had a better OHQoL in physical aspects than those who never had treatment.
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Depth of cure of composite material is restricted and it depends on many parameters such as thickness. The aim of this in-vitro study was to evaluate the depth of cure of two light-cured core build-up composites (Quixfil and Photocore) in different thicknesses, when cured for 60 seconds.The Vickers microhardness measurements were made for each side of the top irradiated surfaces of 1,2,3,4,5,6,7 and 8-mm-thick cylindrical blocks of two core build-up light-cured composites (Quixfil and Photocore) and a micro hybrid composite (Z250) as the control group. For each thickness a bottom to top Vickers Hardness Number (VHN) ratio was determined and a value of at least 80% was used to indicate the acceptable depth of curing. The results were analyzed with two way ANOVA and Tukey HSD test. P value<0.05 was considered significant.A two way ANOVA indicated that both the depth of cure and VHN were significantly influenced by composite type (P< 0.001) and thickness (P< 0.001). The bottom to top VHN ratio reflecting the relative curing degree showed acceptable curing at a depth of 5 mm for Quixfil and Photocore; however, it was 3 mm for Z250. The surface micro hardness of Photocore was significantly higher than the other materials in all thicknesses.Although both two composites can be bulk cured, their curing depths were lower than that was expected. Curing depth is a property which is material specific and decreases with thickness (P < 0.001).
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Treatment planning poses difficulties in edentulous patients for orthognathic surgery prediction and fixation.Treatment of severe class III malocclusion frequently requires orthognathic surgical procedures. For such patients, orthognathic surgery would be the only option before prosthetic rehabilitation.This clinical report describes step-by-step fabrication of a surgical splint for an edentulous 22-year-old patient with a severe class III malocclusion.The patient wound up in class I occlusions and stable prosthodontic rehabilitation.Using splints for planning and guiding the surgery in edentulous patients facilitates accurate positioning of the jaws and saves time in the operating room.
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Incontinentia pigmenti (IP) is an X-linked dominant genodermatosis characterized by typical skin lesions along Blaschko's lines and associated with ocular, dental, nails, hair, skeletal, central nervous system and cardiovascular anomalies. We report a 5-year-old boy with cutaneous hyperpigmentation along Blaschko's lines, atrophic streaks, strabismus and mental retardation. He showed the characteristic abnormal dentition seen in IP as partial hypodontia, peg-shaped anterior teeth and un-erupted teeth. The expression of IP in boys is exceptional as the disease is lethal in males.
