مجله دانشگاه علوم پزشکی شهید صدوقی یزد
سال بیست و یکم شماره 3 (پیاپی 92، امرداد و شهریور 1392)

Human studies have shown that patients with cardiovascular diseases have worse periodontal status. Therefore، this study aimed to investigate the periodontal health in patients with coronary heart diseases who underwent angiography.

In this cross-sectional study، 135 patients with coronary artery disease participated who underwent angiography. Periodontal indices were assessed including bleeding on probing، plaque index، probing depth، furcation involvement، number of missing teeth and number of tooth with pathologic mobility. According to angiography results، the presence of coronary artery stenosis and its severity were recorded based on the number of involvement arteries. Data was analyzed by Mann-whitney test and N par test using spss software (version 16).

According to results of angiography، there were 106 patients with CHD that among them، 65% were with periodontitis، 6. 6% with health periodontium. Out of the remaining 29 patients (with normal result of angiography) 44. 8% had gingivitis and 44. 8% had periodontitis. Probing depth index was significantly different in patients with and without coronary artery stenosis (p<0. 05) whereas there was no significant difference between patients with other periodontal indices (p>0. 05).

Patients with coronary artery disease have worse periodontal status compared to individual with normal angiography.

Mechanical plaque control is the main way to prevent caries and periodontal diseases. Among the mechanical methods، daily use of toothbrush is considered as the best way to achieve oral health. Therefore، the purpose of this study was to evaluate clinical and microbiological efficacy of Hygenic toothbrushes in plaque removal. In this randomized clinical trial، 40 volunteers were selected. Patients were randomly divided into two groups، one group received toothbrushes with battery and the other group received toothbrushes without the battery. At the beginning of the study plaque score was measured and recorded. Patients brushed for a week and plaque was measured again. Then in both groups the first toothbrush was taken and the second brush was received by the volunteers in a cross over manner. In this regard، the mirobiological samples (colony forming units) were determined before and after brushing. Data was analyzed by means of T- tests using the spss software. The results showed that toothbrushes with and without battery reduced plaque score (respectively 98/22% and 26/19%). Colony forming units was reduced for both toothbrushes with battery (6/24%) and without battery (9/5%). This indicates that toothbrushes with battery significantly reduced plaque compared to the ordinary toothbrushes. Hygenic toothbrushes reduce plaque score and microbial counts more effectively than ordinary toothbrushes.

Different light sources influence restoration bond strength. Therefore the purpose of this study was evaluation of the microtensile bond strength of two types of sixth generation adhesives in different light sources. some sound human molars were collected. 10 sample in each group was prepared that totally 60 samples were investigated. In each tooth some dentinal specimen was prepared in buccal surface using diamond bur after abrading the enamel. Composite resin (Z250) was inserted in form of a layer using a Clearfil SE bond and Adper prompt L-POP adhesives. Both adhesives were polymerized using different light curing units including QTH at 600mW/cm2، LED at 400mW/cm2، PAC at1200mW/cm2، G1-Adper /LED، G2-Adper /Plasma، G3-Adper /QTH، G4-SE/LED، G5-SE /Plasma، G6-SE /QTH. The restorations were sectioned with 1mm thickness per teeth. All specimens were then subjected to microtensile testing machines. Then، data were analyzed using SPSS software، ANOVA and T-test. Clearfil SE /Plasma arc group had the highest bond strength. The bond strength of Adper prompt L-POP significantly varied in different light sources (p<0. 05). Significant difference was observed between Adper and SE (p<0. 05) while using LED. This study showed that various light sources have different influence on bond strength.

Radiography is the most common method for measurement of working length، though it is not the ideal method because of technical problems، radiation hazard، superimposition of permanent teeth bud on primary teeth، and so on. Electronic Apex Locator (EAL) is a device for determination of working length. Therefore، this study aimed to compare the accuracy of an electronic apex locator and radiography for determining working length of primary necrotic molars.

sixty canals of twenty necrotic mandibular primary molars were used in children with 5-7 years old. There were no calcified canal، previous root canal therapy and perforation of pulp chamber floor. Access cavity was prepared and working length was determined by means of NSK EAL and conventional radiography and then was compared. Moreover، Pulpectomy was completed. Data were analyzed by Paired Samples T test.

In 56 (93. 3%) of the canals، the length measured by NSK EAL was determined to be equal to the length measured by radiography. In 3 canals (5%)، NSK measurements were found to be less than radiography measurements for 1mm and in 1 canal (1. 7%)، it was greater than radiography measurements for 1mm. T test analysis indicated no significant difference between the two measurement methods (p=0. 85).

Electronic apex locator can accurately assess the length of canals in primary molars.

A CBCT system (Cone Beam Computed Tomography) is a new method in the application of radiography in dental science that provides three-dimensional data of the hard and soft tissue، without magnification or distotion. Information obtained via this diagnostic imaging can be utilized in treatment planning.

In this retrospective descriptive study، the CBCT prescription of all dentists (DDS & Expert) were investigated in a private Center of Oral and Maxillofacial Radiology (426 patients) in Yazd from Oct 2010 to Dec 2012 (26 months) and the following information was extracted: age، sex، years of prescription، reason of prescription، academic level of prescriber. Moreover، data was analyzed utilizing SPSS Version 16.

The study results revealed that 64. 8% of patients aged between 30 to 60 years. Prevalence of male and female patients was approximately equal. Most CBCT prescriptions were by general dentists (44%) and then it belonged to Oral and Maxillofacial Surgeons (32. 2%). CBCT was requested most for implant (88%). Number of CBCT requests in 2010 was 18. 5%; in 2011 was 29. 3% and in 2012 was 52. 1%.

Patients referred for evaluation before implant involve one of the main reasons for the CBCT request. However، it seems that the using CBCT was not limited to implant and will be developed in oral and maxillofacial surgery، orthodontics، root canals therapy and other dental treatments.

Defective restorations such as overhang، overcontour، open margin، residual cement or subgingival margin، lead to severe plaque accumulation and prevent using oral hygiene devices and finally they can cause gingival inflammation and periodontal destruction. Therefore، this study aimed to determine the frequency of restorations that have potentiality of periodontal destruction in participants referred to Faculty of dentistry، Shahid Sadoughi University of Medical Sciences in 2011. In this descriptive cross-sectional study، patients referred to Oral Medicine department were selected to reach 150 participants. All restorations were investigated regarding the existence of overhang، overcontour، open margin، subgingival margin، and residual cement. Totally، 348 restorations were investigated that within 208 amalgam fillings، 88 fillings (42. 30%) were with overhang. Among 79 composite fillings، 17 fillngs (21. 51%) had overhang and overcountour. From 65 metal ceramic crowns، 21 crowns (32. 30%) had open margin and 15 crowns (23. 70%) had subgingival margins. Moreover، residual cement was not found. Existence of defective restorations which interfere with periodontal health such as amalgam overhang (it revealed most frequency in this study) indicates that more attempts are required to decrease such flaws.

soft tissue calcification is a relatively common issue in panoramic radiography. These opacities include calcification of lymph nodes، tonsilolith، sialolith، calcification of stylohyoid complex and carotid artery bifurcation. This study aimed to determine the prevalence of soft tissue calcification in panoramic radiographs، their differential diagnosis، and their correlation with the underlying disease such as diabetes mellitus، tuberculosis، hypertension، cardiovascular disease and cerebrovascular accident. In this study، panoramic radiographs of 510 patients referring to radiology department of shahid sadoughi dental school of Yazd in one year were examined. Moreover، prevalence of soft tissue calcification، their location and factors such as age، sex، underlying disease and smoking were examined. The data was analyzed by Chi-square، Fishers exact test and odds ratio. The prevalence of soft tissue calcification was 2. 0% for calcification of carotid artery، 7. 3% for tonsilolith، 2. 0% for sialolith، 6. 5% for calcified lymph node، 21. 4% for elongated stylohyoid process. There was a significant correlation between ectopic calcification and diabetes mellitus، hypertension، cardiovascular disease and tuberculosis (p-value<0. 05). There was no significant correlation between ectopic calcification and smoking and cerebrovascular accident (p-value>0. 05). The study showed that detection of soft tissue calcification and ectopic calcification on panoramic radiographs should be taken into account، and the dentist should refer the patients to related specialist for more complete examinations.

Characteristics of Dental materials may be examined under stimulated oral conditions like loadcycling and Thermocycling. The aim of this study was to evaluate the effect of loadcycling on microleakage of class V cavity preparations restored with composite and total etch adhesives. One hundred class V preparations (5mm×3 mm and 2. 5mm axial Depth) with incisal margin in enamel and gingival margin in dentin، were prepared in the anterior bovine teeth. The teeth were randomly divided into two groups which restored with single Bond (3M-USA) or excite (Ivaclar/viva dent/Lichtenstein). Each group was further divided into five subgroups. The numbers of used loadcycles involved respectively 0، 50k، 100k، 200k، 300k. [K=1000]; Then، all the teeth were covered with sticky wax except 1mm around the samples and were immersed in 2% methylene blue for 24 hours. Then all the teeth were sectioned longitudinally and the scores of Dye penetration were registered under stereomicroscope. The study data were analyzed using kruskal Wallis and Mann Whitney and wilcoxon tests. All the dentin margins showed higher microleakage than enamel margin (P=0. 0001). There was no significant difference between the microleakage of single bond and Excite (P>0/05). The effect of the number of loadcycles on the microleakage of the single bond and Excite in dentin and enamel margin was not significant. Enamel margins showed less microleakage than dentin margins. This study did not show any increase in microleakage after increasing the number of loadcycles

Patients receiving orthodontic treatment get some alterations in their oral cavity environment such as an increase in the levels of microorganism in oral cavity and dental biofilms. Therefore، this study aimed to evaluate as well as to compare the colonization of mutans streptococci in different parts of removable orthodontic appliances. In this descriptive analytic study، samples were obtained before and after use of removable appliance plaque and amount of colonization of streptococci mutan was determined in 3 areas including Biteplaque in proximity of first molar teeth، spring، inner surface of removable appliance in proximity of first molar Results showed that plague index increased significantly after use of removable appliance. (P<0. 001); There was a significant difference in amount of colonization of streptococci mutans between spring and biteplaque (p= 0. 028) This study indicated importance of a precise oral hygiene control in patients under treatment with removable orthodontic appliances for prevention of dental caries.