مجله تحقیق در علوم دندانپزشکی
سال سیزدهم شماره 4 (پیاپی 50، زمستان 1395)

The limitation of the curing depth is one of the problems occurring while working with light curing composites which leads to clinical failure of restorations. Using the bulk fill flowable composites have been introduced as a solution to this problem, yet the researches have not had consonant results; That is why, we decided to evaluate the effect of different thicknesses on polymerization of three types of bulk fill and hybrid composites.
Method and Material: In this In-Vitro study, we put 108 specimens of two types of bulk fill flowable composites, Filtek™ Bulk Fill Flowable(FBF) and X-tra Base(XB), and a hybrid composite, Filtek™ Z250 Universal(Z250) as control samples, in brazen molds with 2.4.10 mm dimensions. After light curing for 20 seconds by Demi™ Plus light cure device, calibrated by the Minamel radiometer device, we put the specimens in CO2 Incubator at 37°C for 24 hours, then we measured the Vickers microhardness of specimens by Vickers V-Test ll machine under 300 grams force for 15 seconds. The measurements were done three times respectively at the depths of 0.1-1-2-3-4-5 and the averages were calculated. The results were then analyzed using the ANOVA statistical testing.
The highest microhardness was shown by Filtek™ Z250 Universal at the depth of 0.1 mm (98.8±0.8) and the lowest microhardness was shown by Filtek™ Bulk Fill Flowable(FBF) at the depth of 5 mm (31.5±0.7). The detected differences at all of the six depths were statistically significant(p It seems that the microhardness of Filtek™ Z250 at the surface of restoration is better than that of the two other composites.

In the past twenty years, widespread using of synchronous dental restorations, engendered many challenges resulting in different questions regarding to the method of surface preparation of the porcelain restorations and its relationship with discolorations in long-term use. The effect of mouth rinses on discoloration of dental ceramics with different surface preparations faces an information gap across the studies, which has made by now. This study has conducted to evaluate the effect of chlorhexidine mouth rinse on color stability of CERAMCO III dental porcelains.
This experimental study conducted under in-vitro conditions. A number of 20 disc-shaped specimens prepared and divided to two groups of glazed and polished porcelain. After baseline color measurements, for a period of 30 days all specimens were immersed in 200ml of 0.2% Chlorhexidine mouth rinse under controlled environmental conditions. By the end of this immersion process, the color change of the specimens measured using a spectrophotometer device. The Data were statistically analyzed using 2-WayANOVA. Overall color changes was determined using the CIE-L*a*b* system.
All the specimens displayed color changes after immersion in considered solution. Polished specimens exhibited a little bit more color change in two coordinates, but color shift of both groups were relatively the same and they were not statistically significant. 0.98±0.08 and 0.81 ±0.19 in polished and glazed group respectively. (p The color stability in both groups of polished and glazed porcelains are clinically acceptable, and the different surface preparation methods has no significant effect on porcelain surface discoloration in Chlorhexidine mouth rinse solutions.

The most important features of dental materials is physical surface. One of these features is interfacial effect of solid–fluid that evaluated in standard situation with contact angle and the surface tension is directly related to it. This study was aimed to evaluate two mouth-rinse contact angle with difference base on two restorative materials.
Method & Material: In this experimental study we has made 15 composites dick, 15 Glass Ionomers) disk with 6mm diameter and 2mm thickness and good surface roughness and used artificial saliva as control group, chlorhexidine and persica mouth-rinse and Contact angle of each instilled drop of liquids on the surface of restorative materials was measured whit profile imaging in the same condition. The obtained data were analyzed by ANOVA and Tukey.
the most contact angle was in artificial saliva on composite surface (55.7 ͦ) and the least of them was chlorhexidine in Glass Ionomer surface (33 ͦ). Also there was Significant differences between all conditions studied (P in this study Between two restorative materials, composite (hydrophobic) and glass ionomer (hydrophilic) contact angle of artificial saliva, persica and chlorhexidine on the more hydrophilic material (glass ionomer) is lower and among the solutions used, chlorhexidine contact angle on the both restorative material is less.

Obesity is the most common nutritional disorder and is a significant risk factor for numerous adult diseases including periodontitis. The aim of this study was to investigate the association of human body composition (obesity) and periodontal disease using wireless body analysis scale in individuals aged 18 to 36 years.
140 individuals (70 normal and 70 obese subjects) were evaluated in this historical cohort study. The periodontal examination consisted of: Probing Pocket Depth (PPD), Clinical Attachment Level (CAL), Plaque Index (PLI) and Bleeding on Probing (BOP). Body Mass Index (BMI) and body composition parameters (consisting of Body Water, Body Fat, Muscle Mass, Bone Mass, Lean Mass and Visceral Fat) were measured using ihealth scale body analysis hs-5 device. Sociodemographic variables and periodontal disease risk indicators were evaluated as covariates. Results were evaluated by Mann-U- Whitney tests and Spearmen coefficient calculation.
All periodontal indexes were significantly higher in the case group compared to control (P The results of this study indicate that there are correlations between human body composition and periodontal status in young adults.

Back ground & Aim:According to the research on cutaneous squamous cell carcinoma, complement factor I may play a role in progression of oral squamous cell carcinoma. The aim of present study was to evaluate immunohistochemical expression of complement factor I in oral squamous cell carcinoma.
In this case-control study, studied groups were consisted of paraffin-embedded tissue blocks of 30 oral squamous cell carcinoma samples and 30 normal oral mucosa samples. 4 μ sections were prepared from tissue blocks and stained with complement factor I antibody using immunohistochemistry technique. In this study, percentage of stained cells and staining intensity of them was considered and data analyzed by MANN-U-WHITNEY test. Significance level was P-value 25 cases of normal mucosal samples and 5 cases of oral squamous cell carcinoma samples didn’t stain with this antibody. Mean percentage of stained cells in normal mucosa was 0.015 and in oral squamous cell carcinoma was 0.060 (PIt seems that complement factor I play a role in development of oral squamous cell carcinoma

Due to abundant cases of impacted third molar surgery and the prevalence of close relationship between mandibular third molar root and inferior alveolar canal, and the importance of prevention of nerve injury during surgery, this study was performed to compare panoramic radiography with CBCT Scan in diagnosis of relationship between mandibular third molar root and inferior alveolar canal, based on observed nerve during surgery.
the diagnostic study was conducted on extraction of third molar teeth while at least one sign indicating the proximity between, the canal and the tooth in panoramic radiography. Radiographic signs of each sample were assessed in both panoramic radiography and CBTC Scan. Third molar teeth were extracted surgically by two maxillofacial surgeons. Presence or absence of exposure during surgery as the standard criterion was recorded. Diagnostic ability of panoramic radiography in comparison with CBTC Scan was analyzed using proportion test.
The study was performed on 120 samples. In panoramic radiographies the positive predictive value was equal to 67.7 % & negative predictive value was 32.3%, while In CBTC Scan the positive and negative predictive values, were 93.3% and 6.7%, respectively.(p Panoramic radiography cannot be the same as CBCT scan in diagnosis of relationship between mandibular third molar root and inferior alveolar canal.

Fungal Oral diseases affect the majority of the population and can affect a person’s overall health. It is reported that chamomile extract contain phytomedicine capabale of suppressing oral pathogens associated with fungal diseases. The aim of this study is the assessement of chamomile extract antifungal activity on Candida albicans.
The reference strain of C. A ATCC 10231 used for this study. The70% ethanol extract of chamomile was and then made in 2-512 mg/ml concentrations. The antifungal activity of the extract was examined by determining Minimum Inhibitory Concentration (MIC) and Minimam Fungicidal Concentration (MFC) using the macro broth dilution technique and agar well diffusion method.
Results showed that the ethanol extract of Chamomile had inhibitory and fungicidal effect only in concentration of 512 mg/ml.
Comparison of the results of ethanol control group and test group showed that inhibitory and fungicidal effect of hydroalcoholic extract of chamomile is due to 70% Ethanol but not the chamomile and Ethanol extracts of chamomile has no antifungal effect on Candida albicans.

Since the study of images quality taken with dental portable radiographic devices is not carried out, the aim of this study was to compare the quality of radiographs taken with Diox 602 portable device and Min Ray fixed device with each other.
This experimental study was performed on 10 patients with request of more than 10 intraoral radiographs were almost symmetrically from both sides of the jaws. Half of radiographs per patient were performed using a portable device and the other half using fixed device by Kodak intraoral films. Then they were developed and fixed by automatic processing in the same condition. After coding, radiographs were examined by three oral and maxillofacial radiologists by four defined criteria in terms of density, contrast, resolution and noise. To each of the qualitative criteria was given a rating of acceptable or unacceptable. The weighted kappa coefficient was 90% for inter-observer reproducibility. The results were analyzed using Chi-square test.
From a total of 109 radiographs, 58 radiographs were taken by portable device (Diox 602) and 51 radiographs by fixed device (Min Ray). Most of the radiographs were evaluated at an acceptable level in terms of ranking in each of the qualitative parameters and no significant difference was noted between two groups in any parameter (P Quality of the images taken by the portable X-ray machine (Diox 602) showed no significant difference compared with fixed X-ray machine (Min Ray).

Traumatic mandibular condylar injuries occur commonly and generally present as condylar neck fractures or dislocations of the temporomandibular joint. On the other hand, intrusion of the mandibular condyle into the middle cranial fossa, with or without a simultaneous fracture of the mandible, is extremely rare. This article presents the case of a young female with central dislocation of the right mandibular condyle after facial trauma.
Case report: A 10 year-old healthy girl was involved in a car rolling accident and transported to emergency room of the hospital. The girl presented no loss of consciousness. Extra-orally a small laceration of the chin was noted. Facial asymmetry was found. And intra-orally and anterior open bite and mandibular dental midline shift was evident. Under IV sedation, a closed reduction was performed. After 24 hours, she returned with right condylar re-dislocation. Facial CT scans were requested and central dislocation of the right mandibular condyle was found. Conservative treatment was considered and she was followed-up for 30 days.
Early diagnosis with accurate clinical and radiographic examinations is essential to detect and treat this kind of injury successfully, thereby avoiding delayed treatment, as well as related complications like ankylosis of the temporomandibular joint. Various methods of treatment for intracranial dislocation of mandibular condyle have been suggested, ranging from closed reduction techniques with manual manipulation to open reduction combined with intracranial bone grafting. Closed reduction is a useful technique in young children who have sustained injuries within a 4-week time frame