Comparison of autogenous bone graft and tissue-engineered bone graft in alveolar cleft defects in canine animal models using digital radiography.

BACKGROUND: Autogenous bone graft is the gold standard for repair of bone defects. However, osteoprogenitor stem cells are suggested as an alternative treatment. Aims: To quantitatively compare bone formation in autogenous bone graft and tissue-engineered graft using digital radiography densitometry software in canine alveolar cleft model. SETTING AND DESIGN: This experimental study on animal models was conducted in Isfahan University of Medical Sciences. METHODS: Mesenchymal stem cells (MSCs) were obtained from subcutaneous adipose tissue of 4 dogs. Undifferentiated cells were incubated with a hydroxyapatite/beta-tricalcium phosphate scaffold in an osteogenic medium for 21 days. A maxillary defect simulating human alveolar cleft was created from the alveolar crest to nasal floor with 15 mm width bilaterally. Two months later, the defect was filled with autogenous bone graft harvested from tibia on one side and tissue-engineered graft from MSCs on the other side. Digital radiography was performed on days 15, 30, 45, 60, 75, and 90 after grafting. Radiographic density was calculated by the mean numeric value of pixels of the desired area ranging from 0 (darkest) to 255 (lightest) by associated software. STATISTICAL ANALYSIS USED: The data were analyzed by Statistical Package for the Social Sciences using descriptive statistics and two-way repeated-measure analysis of variance test (α = 0.05). RESULTS: Mean density measured for autogenous bone graft group was 110.72, 82.70, 75.76, 93.57, 100.22, and 100.32 in days 15, 30, 45, 60, 75, 90, respectively and 120.7, 87.62, 83.72, 92.02, 92.30, and 93.77 in stem cell group. Although the time lapse was a significant factor in two groups (P = 0.01), the results indicated that the difference between two groups was not statistically significant (P = 0.942). CONCLUSION: Tissue-engineering can be used as an alternative method in reconstruction of bony defects with predictable clinical outcomes.

Central unilocular mucoepidermoid carcinoma of the mandible: A case report and literature review.

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. Central MEC (CMEC) is a rare tumor which affects women more than men and is more common in the mandible. Most cases are histologically classified as low-grade tumor and radiographically appear as well-defined unilocular or multilocular radiolucent lesion, although this tumor causes destruction and metastasis to other organs. In this article, we present a rare case of CMEC in a 47-year-old woman with unilocular radiolucent lesion of the mandible. Early and accurate diagnostic approach in all lesions with clinical/radiographical bland appearance is important, and all possibilities such as a malignant lesion should be considered.

Comparison of sealing ability of ProRoot mineral trioxide aggregate, biodentine, and ortho mineral trioxide aggregate for canal obturation by the fluid infiltration technique.

BACKGROUND: Adequate seal of the root canal is necessary to prevent recontamination and ensure the long-term clinical success. The aim of this study was to evaluate the sealing ability of ProRoot mineral trioxide aggregate (MTA), Biodentine, and Ortho MTA as the root canal obturation materials using the fluid infiltration method. MATERIALS AND METHODS: In this invitro study a total of 66 extracted human mandibular premolars were randomly divided into five groups according to the material used for the root canal obturation. Group I - ProRoot MTA (20 samples), Group II - Biodentine (20 samples), Group III - Ortho MTA (20 samples), Group IV - negative group (3 samples), and Group V-positive group (3 samples). MTA, Biodentine, and Ortho MTA were applied using a cotton-tipped K-file #30 and hand plugger into the root canals of each group. In Group 4 (negative control), no filling material was used. In Group 5 (positive control), a single gutta-percha size #40 was inserted into the root canal without using a sealer. The teeth were mounted and exposed to the fluid infiltrarion system. Statistical analysis was performed using Kruskal-Wallis test the level of significance was set at α = 0.05. RESULTS: Mean values of microleakage in MTA ProRoot, Biodentine and Ortho MTA groups were 1.83 ± 0.62, 1.95 ± 1.27 and 1.72 ± 0.83 µL in 8 minutes. No statistically significant difference was observed between the sealing ability of ProRoot MTA, Biodentine, and Ortho MTA (P = 0.091). CONCLUSION: Within the limitations of this study, microleakage values were similar to MTA ProRoot, Biodentine, and Ortho MTA using the fluid infiltration technique.

Comparative evaluation of apical constriction position in incisor and molar teeth: An in vitro study.

OBJECTIVE: The apical constriction (AC) and the apical foramen (AF) are the principal reference points used to determine the apical limit for instrumentation and root canal filling. AC varies in different races, and the aim of the current study was to measure and compare the distances from AC to AF and the anatomical apex (AA) in incisor and molar teeth in the Iranian population. MATERIALS AND METHODS: Forty-five roots of incisor teeth and 45 roots of molar teeth were selected randomly in Isfahan Province, Iran. If the foramen was located toward the mesial or distal side of the apex, the cut was made mesiodistally, and if it was toward the buccal or lingual side, the section was made accordingly. Roots were examined under a microscope at ×25 magnification. The distances from AC to AF and AA were then estimated using a Motic camera. Descriptive statistics were used. The independent t-test was also used to compare distances in incisors and molars, and P = 0.05 was deemed to indicate statistical significance. RESULTS: The mean distances between AC and AF were 0.847 ± 0.33 mm in incisors and 0.709 ± 0.27 mm in molars. The mean distances between AC and AA were 1.23 ± 0.39 mm in incisors and 1.01 ± 0.38 mm in molars. In an independent t-test, the distances between AC and AF differed significantly in incisors and molars (P = 0.035), but the distances between AC and AA did not (P = 0.172). CONCLUSION: The end points for root canal therapy should be 0.85 mm in incisors and 0.70 mm in molars.

Rare and Extensive Malignant Melanoma of the Oral Cavity: Report of Two Cases.

Primary oral melanomas are uncommon malignant neoplasm of melanocytes origin. The most common site of oral melanoma is maxillary gingiva and hard palate. Oral mucosal melanoma exhibit a pathobiological behavior and clinical features different from cutaneous melanomas. Oral melanomas are often clinically silent which may consequently result in delayed diagnosis; thus, making the prognosis extremely poor. This case report presents clinical, histopathological and immunohistochemical features of two cases of advanced oral melanoma, one pigmented or melanotic melanoma in a 46-year-old female and another amelanotic melanoma in a 59-year-old male patient, with chief complaint of swelling in oral mucosa. Most oral melanomas are usually asymptomatic lesions with quick growing. Thus, the most cases are detected in late stage of diagnosis. Early diagnosis with careful examination by dentists, and early biopsy of pigmented and suspicious non-pigmented lesions would have an imperative role in more survival rate and better prognosis.

Determination of salivary urea and uric acid of patients with halitosis.

BACKGROUND: Halitosis is the presence of unpleasant or foul smelling breath. The origin of halitosis may be related to both systemic and oral conditions, but a large percentage of cases, about 90%, is generally related to an oral cause. The aim of this study was to compare the concentration of urea and uric acid in patients with halitosis and people without halitosis. MATERIALS AND METHODS: In this case-control study, concentration of urea and uric acid was compared between two groups: (1) persons suffering halitosis (2) control group without halitosis. Each group includes fifty patients. Unstimulated saliva was collected in both groups. Then, concentration of urea, uric acid, and creatinine was determined. The results were statistically analyzed with SPSS software version 14 (SPSS Inc., Chicago, Illinois, USA) by t-test (α = 0.05). RESULTS: Results showed that salivary urea and uric acid concentration in halitosis group were significantly greater than control group (P < 0.05). Salivary creatinine concentration in halitosis group was significantly lower compared to control group (P < 0.05). Salivary urea and uric acid concentration to creatinine ratios were higher in halitosis group than control group, and significant differences between them were existed (P < 0.05). CONCLUSION: According to the results, urea and uric acid concentration show increase in patient suffering halitosis, and this increase may result in oral malodor.

Evaluation of orthognathic surgery on articular disc position and temporomandibular joint symptoms in skeletal class II patients: A Magnetic Resonance Imaging study.

BACKGROUND: The purpose of orthognathic surgery is to correct facial deformity and dental malocclusion and to obtain normal orofacial function. However, there are controversies of whether orthognathic surgery might have any negative influence on temporomandibular (TM) joint. The purpose of this study was to evaluate the influence of orthognathic surgery on articular disc position and temporomandibular joint symptoms of skeletal CI II patients by means of magnetic resonance imaging. MATERIAL AND METHODS: For this purpose, fifteen patients with skeletal CI II malocclusion, aged 19-32 years (mean 23 years), 10 women and 5 men, from the Isfahan Department of Oral and Maxillofacial Surgery were studied. All received LeFort I and bilateral sagittal split osteotomy (BSSO) osteotomies and all patients received pre- and post-surgical orthodontic treatment. Magnetic resonance imaging was performed 1 day preoperatively and 3 month postoperatively. Descriptive statistics and Wilcoxon and Mc-Nemar tests were used for statistical analysis. P<0.05 was considered significant. RESULTS: Disc position ranged between 4.25 and 8.09 prior to surgery (mean=5.74±1.21). After surgery disc position range was 4.36 to 7.40 (mean=5.65±1.06). Statistical analysis proved that although TM disc tended to move anteriorly after BSSO surgery, this difference was not statistically significant (p value<0.05). CONCLUSIONS: The findings of the present study revealed that orthognathic surgery does not alter the disc and condyle relationship. Therefore, it has minimal effects on intact and functional TM joint. Key words:Orthognathic surgery, skeletal class 2, magnetic resonance imaging, temporomandibular disc.

Human Pulp Response to Direct Pulp Capping and Miniature Pulpotomy with MTA after Application of Topical Dexamethasone: A Randomized Clinical Trial.

INTRODUCTION: The aim of this randomized clinical trial was to compare the histologic pulp tissue response to one-step direct pulp capping (DPC) and miniature pulpotomy (MP) with mineral trioxide aggregate (MTA) after application of dexamethasone in healthy human premolars. METHODS AND MATERIALS: Forty intact premolars from 10 orthodontic patients, were randomly chosen for DPC (n=20) or MP (n=20). In 10 teeth from each group, after exposure of the buccal pulp horn, topical dexamethasone was applied over the pulp. In all teeth the exposed/miniaturely resected pulp tissue was covered with MTA and cavities were restored with glass ionomer. Teeth vitality was evaluated during the next 7, 21, 42, and 60 days. Signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. According to the orthodontic schedule, after 60 days the teeth were extracted and submitted for histological examination. The Kruskal-Wallis and Fisher's exact tests were used for statistical analysis of the data (P=0.05). RESULTS: Although dexamethasone specimens showed less inflammation, calcified bridge, pulpal blood vasculature, collagen fibers and granulation tissue formation were not significantly different between the groups (P>0.05). CONCLUSION: Topical dexamethasone did not hindered pulp healing but reduced the amount of underlying pulpal tissue inflammation after DPC and MP in healthy human premolars.

Synergic phototoxic effect of visible light or Gallium-Arsenide laser in the presence of different photo-sensitizers on Porphyromonas gingivalis and Fusobacterium nucleatum.

BACKGROUND: According to the development of resistant strains of pathogenic bacteria following treatment with antimicrobial chemotherapeutic agents, alternative approaches such as lethal photosensitization are being used. The aim of this study was to evaluate the effect of visible light and laser beam radiation in conjugation with three different photosensitizers on the survival of two main periodontopathogenic bacteria including Porphyromonas gingivalis and Fusobacterium nucleatum in different exposure periods. MATERIALS AND METHODS: In this in vitro prospective study, strains of P. gingivalis and F. nucleatum. were exposed to visible light at wavelengths of 440 nm and diode laser light, Gallium-Arsenide, at wavelength of 830 nm in the presence of a photosensitizer (erythrosine, curcuma, or hydrogen peroxide). They were exposed 1-5 min to each light. Each experiment was repeated 3 times for each strain of bacteria. Data were analyzed by two-ways ANOVA and least significant difference post-hoc tests. P < 0.05 was considered as significant. After 4 days the colonies were counted. RESULTS: Viability of P. gingivalis was reduced 10% and 20% subsequent to exposure to visible light and diode laser, respectively. The values were 65% and 75% for F. nucleatum in a period of 5-min, respectively. Exposure to visible light or laser beam in conjugation with the photosensitizers suspension caused significant reduction in the number of P. gingivalis in duration of 5-min, suggesting a synergic phototoxic effect. However, the survival rate of F. nucleatum following the exposure to laser with hydrogen peroxide, erythrosine and rhizome of Curcuma longa (curcumin) after 5-min was 10%, 20% and 90% respectively. CONCLUSION: Within the limitations of this study, the synergic phototoxic effect of visible light in combination with each of the photosensitizers on P. gingivalis and F. nucleatum. However, the synergic phototoxic effect of laser exposure and hydrogen peroxide and curcumin as photosensitizers on F. nucleatum was not shown.

Fracture resistance of structurally compromised and normal endodontically treated teeth restored with different post systems: An in vitro study.

BACKGROUND: With the aim of developing methods that could increase the fracture resistance of structurally compromised endodontically treated teeth, this study was conducted to compare the effect of three esthetic post systems on the fracture resistance and failure modes of structurally compromised and normal roots. MATERIALS AND METHODS: Forty five extracted and endodontically treated maxillary central teeth were assigned to 5 experimental groups (n=9). In two groups, the post spaces were prepared with the corresponding drills of the post systems to be restored with double taper light posts (DT.Light-Post) (group DT.N) and zirconia posts (Cosmopost) (group Zr.N). In other 3 groups thin wall canals were simulated to be restored with Double taper Light posts (DT.W), double taper Light posts and Ribbond fibers (DT+R.W) and Zirconia posts (Zr.W). After access cavity restoration and thermocycling, compressive load was applied and the fracture strength values and failure modes were evaluated. Data were analyzed using two-way ANOVA, Tukey and Fisher exact tests (P<0.05). RESULTS: The mean failure loads (N) were 678.56, 638.22, 732.44, 603.44 and 573.67 for groups DT.N, Zr.N, DT.W, DT+R.W and Zr.w respectively. Group DT+R.W exhibited significantly higher resistance to fracture compared to groups Zr.N, DT.W and Zr.w (P<0.05). A significant difference was detected between groups DT.N and Zr.W (P=0.027). Zirconia posts showed significantly higher root fracture compared to fiber posts (P=0.004). CONCLUSION: The structurally compromised teeth restored with double taper light posts and Ribbond fibers showed the most fracture resistance and their strengths were comparable to those of normal roots restored with double taper light posts. More desirable fracture patterns were observed in teeth restored with fiber posts.

Effect of MTAD on the shear bond strength of self-etch adhesives to dentin.

BACKGROUND: As the use of different irrigants to eliminate residual debris and smear layer in the field of endodontic is unavoidable, by considering the effect of irrigants on the bond strength of resin composite restorations, this study was designed to evaluate the effect of a mixture of a tetracycline isomer, an acid, and a detergent (MTAD) on the shear bond strength of two self-etch adhesives, Clearfil SE Bond and Adper Prompt L- Pop to dentin. MATERIALS AND METHODS: The crowns of 80 extracted premolars were transversally sectioned to expose dentin. Flat dentin surfaces were wet abraded with 320-grit abrasive paper and randomly assigned to eight groups according to two self-etch adhesive and four dentin surface treatments: direct application over smear layer (no treatment), etching with 35% phosphoric acid for 15s, 1 min 5.25% NaOCl/1 min MTAD and 20min 1.3% NaOCl/5min MTAD. Shear bond strength was tested 24 h after storage in distilled water at 37°C in incubator. Data were analyzed using one-way ANOVA followed by duncan post-hoc (α=0.05). RESULTS: Phosphoric acid etching prior to SE Bond application significantly decreased the shear bond strength to dentin (P<0.05). Application of MTAD clinical protocol (20min 1.3% NaOCl/5min MTAD) did not significantly decrease the shear bond strength of self-etch adhesives to dentin (P=0.745) CONCLUSIONS: Based on the results of present investigation, it seems that the use of clinical protocol of 1.3% NaOCl as a root canal irrigant and a 5-min application of MTAD as a final rinse to remove the smear layer has no adverse effect on the shear bond strength of self-etch adhesives to dentin.

Distribution assessment of maxillofacial fractures in trauma admitted patients in Yazd hospitals: An epidemiologic study.

BACKGROUND: Fracture, is discontinuity of anatomical bone relations. Commonly, a maxillofacial fracture occurs after trauma but the etiology and pattern of this entity is different amongst countries. The aim of this study was to clarify the main causes of this entity in Yazd to increase public and professional awareness to prevent more injuries and subsequent consequences. MATERIALS AND METHODS: This retrospective cross-sectional study consisted of 194 patients admitted in public hospitals in Yazd, Iran. Variables such as age, gender, cause of accidents, site of fracture and treatment method were noted and recorded in a questionnaire filled during hospitalization of these patients. Causes of accident were classified by 6 reasons such as accident by car and motorcycle, fighting and violence, falls, sports and occupational injuries. The site of fractures, including mandible, maxilla, nasal, frontal and orbital were considered. The data were analyzed using descriptive analysis. RESULTS: The results showed that maxillofacial fractures are more prevalent in male than females (69% versus 31%). The Most sites of fractures were nasal bone (79%). The majority of people with maxillofacial fractures were in the age ranged between 20-29 years and the main reason of maxillofacial fractures was motorcycle accident. CONCLUSION: According to our result, most sites of fractures were in nasal bone. The main cause of maxillofacial fractures was motorcycle accident. However, in each age range the most common cause of accident was different.

Evaluation of relative distribution and risk factors in patients with dry socket referring to Yazd dental clinics.

BACKGROUND: Dry socket is one of the most prevalent complications occurring after tooth extraction. The prevalence of such condition has been reported to be highly different, ranging from 0.5 to 68.4%. The etiology and pathogenesis of this entity are not clearly known and many related predisposing factors have been discussed. The goal of this study was to evaluate the relative prevalence of this entity after tooth extraction and determine the contributing factors in patient referring to Yazd dental clinics. MATERIALS AND METHODS: This cross-sectional prospective study was carried out at Yazd dental clinics (from May 2010 to Jun 2010). Four thousand seven hundred and seventy nine patients were selected and included in our study. Characteristics such as: age, gender, site of extraction, number of extracted tooth, trauma during extraction, oral hygiene, smoking, systemic disease, menstrual cycle, history of dental infection and oral contraceptive pill intake were determined and data was analyzed using descriptive statistical analysis and Fisher's exact test. P value ≤0.05 was considered significant. RESULTS: Over the two-month period of the study, among of 4,779 patients, 28 patients returned with dry socket phenomena. Our results showed that the incidence of dry socket was 0.6% and females were more common involved than males (0.08% versus 0.04%). The ratio of mandible to maxilla was 2.5 to1 and mandibular third molars were more often involved than other teeth. Trauma, poor oral hygiene and smoking had increased the incidence of dry socket. CONCLUSION: The results of our study suggested that trauma during surgery or extraction and poor oral hygiene are important factors that increase the incidence of dry socket, these factors should be considered before and after tooth extractions.