نشریه تحقیقات دندانپزشکی
سال سوم شماره 4 (پیاپی 6، زمستان 1393)

The penetration of microorganisms and irritants into dentinal tubules necessitates utilizing some kinds of material to chemically clear the canal. Therefore, the present study aimed to compare the
anti-bacterial effect of Peranacid M2 with Sodium Hypochlorite and Chlorhexidine.

In this experimental-laboratory study, Muller-Hington medium was prepared containing 5% of sheep blood. After root canal preparation, the discs containing 5.25% Sodium Hypochlorite, 2% Chlorhexidine, and Pranacid M2 were exposed to Enterococcus Fecalis. Each disc was located on a plate with a 2 cm distance from another and then, the plates were incubated in 37 °C for 24 hours. After ending the incubation period, the average diameter of inhibition zone was measured around the discs (in millimeter). This procedure was repeated 10 times for every irrigator. The study data were analyzed via SPSS software (ver.17) applying ANOVA and Tukey HSD tests.

A significant difference was observed in the diameter of antimicrobial zone of the three irrigating solutions (P=0.0001). The most anti-bacterial effects were observed in 5.25% Sodium Hypochlorite (27.3±2.05) and then 2% Chlorhexidine (18.9±1.28). In addition, the least effect was reported in Peranacid M2(10.3±1.41).

Taking the limitations of an in vitro study into account, Peranasid M2 seems to possess less antibacterial effect compared to 5.25%  Sodium Hypochlorite and 2% Chlorhexidine.

Odontogenic myxomas are benign but locally aggressive neoplasms arising from odontogenic ectomessenchyme found almost exclusively in the jaws and arise only occasionally in other bones.

.By a brief review of clinical and radiological features, and also diagnostic and operative dilemmas in assessment a rare case of adontogenic myxoma was presented, which was occurred in the mandible of a 26-year-old femal palient.

Careful evaluation of clinical features and radiographic imaging with detailed assessment of histpathology leads to correct diagnosis

Chronic renal failure is regarded as one of the main serious problems of general health worldwide. In fact, it is associated with different oral manifestations. Therefore, this study aimed to evaluate the frequency of clinical oral findings of dialysis patients in Yazd in 2012.

This descriptive cross-sectional study was conducted among 95 dialysis patients who were selected via convenience sampling method from Apr 2012 to Jun 2012 in three Yazd hospitals. The required study data were collected by clinical examinations and a checklist involving the frequency of oral manifestations (dry mouth, unpleasant mouth taste, the coated tongue, history of systemic disease and previous prescription of systemic medications). The statistical analyses were performed using SPSS Software (ver 17) via descriptive statistics and the significance level was set at 5% (P-value<0.05).

The patients’ mean and age range were 59.04, 19-77 years old, respectively. There were a total of 42 females (44.2%) and 53 males (55.8 %) in the study. Dry mouth, coated tongue and unpleasant mouth taste frequency were reported to be observed in 89.6%, 56.3% and 89.6% of patients, respectively. All the patients had a history of a systemic disease and cardiovascular disease was the most common systemic diseases after the urological and nephrological disease. The cardiac and anti-hypertensive medications (91.6%) were regarded as the most common among the participants after 100% vitamin  usage.

The findings of the present study showed a high frequency of oral manifestations among dialysis patients which can affect patients’ quality of life as a secondary condition. As a result, these oral manifestations are recommended to be monitored among dialysis patients and the relevant treatments need to be applied.

The association between missing posterior teeth and development of temporomandibular disorders (TMD) are controversial. Therefore, the purpose of this was evaluation of the relation between missed posterior teeth and temporomandibular joint disorder.

In this case- control  study, 102 patients  with missing posterior teeth and 102 with all posterior teeth were selected. The TMD examination were performed in all patients and TMD were recorded  for  two groups. Then, the data were collected and analyzed using SPSS 16 software, Chi-square and T-test.

The sample consisted of 106 (%52) men and 98 (%48) women, with the mean age of 27.02±4.87 years, and the age range 15-35 years. There was significant relationship between the missed posterior teeth and prevalence of Temporomandibular joint Disorder (TMD) (P<0.001). Although there was difference among the to prevalence of Temporomandibular joint Disorder (TMD) between two groups, but the difference was not statistically significant (P>0.05).

The results indicated that individuals who lose posterior teeth, have a higher prevalence of Temporomandibular joint Disorder(TMD).

Biopsy is a prerequisite step for identifying and diagnosing the maxillofacial lesions. Among this, proper transfer of samples to the laboratories may have an important effect on the pathologist’s diagnosis and reported result. The aim of this study was to evaluate the knowledge of general dentists’ of indications and contraindications of biopsy, proper manipulation, preservation and transferring specimens.

In this descriptive cross-sectioned study, 111 general dentists were attended in Yazd, in 2012. Data were collect using valid and reliable questionnaires. The questionnaires were included two parts: demographic information (age, gender, professional experience) and the knowledge questions. Data were analyzed by SPSS 17 software, ANOVA and T-test.

Out of 111 general dentists (mean age 34.6 ± 9.49), 51 (46%) were male and 60 (54%) were female. The mean score of dentists’ knowledge was recorded as 5.43±1.53. The average knowledge score  in different age groups showed the significant difference (P-value=0.029). However, this relationship in terms of gender ((P-value=0.172) and the previous professional experience ((P-value=0.160) was not significantly differente.

Based on the results of this study, general dentists’ knowledge was not in a desirable level in Yazd. Therefore, continuous training during the studies, and also after graduation is necessory to improve scientific and practical skills.

Mental health is the most effective factor in the improvement of the student’s talents. This study was designed to determine the relationship between mental health and stident’s educational status of Shahid Sadoughi University of Medical Sciences in 2012.

This cross sectional study was done on 295 students of Yazd Shahid Sadoughi Universtiy of Medical Sciences (291 female, 103 male). Sampling was randomly done. The information was collected by Goldberg General Health Questionnaire and demographic factors. To determine the students with problems, it was used the cutoff points of 23 for general health score (0-84) and for each area (0-21) the cut-off points of 6 was used. Data were analyzed using SPSS 16 software , ANOVA statistical analysis,
and T-test.

131 students (4.44%) had physical or mental disorders ( cut-off point of 111). There were 23 students (6.37%) with impaired physical function, 129 students (7.43%) with anxiety disorder, 172 students (29.58%) with social dysfunction, and 59 students (20%) had depression (cut-off point of 6). There was a significant difference between the rates of depression ( P=0.021) and impaired social function (P=0.035) by using grade point average (GPA). The mean of physical dysfunction, anxiety, depression and social dysfunction was higher in married students rather than the nsingle ones.

According to the high incidence of mental disorders, more attention to the problems of student mental health and student counseling centers seems necessary.

Hand hygiene is considered as the most important aspect to reduce the transmission of infection in healthcare settings. Therefore, the present study was accomplished to evaluate dentists, specialists and dental nurses’ knowledge and practice about hand hygiene in Yazd in 2011.

In this descriptive cross-sectional study, 192 general dentists, specialists and dental nurses were selected randomly in Yazd and their knowledge and practices of hand hygiene were assessed through a questionnaire, validity and reliability of the questionnaire wasapproved. This questionnaire consisted of 19 questions related to knowledge and 17 questions related to practice of hand hygiene.  Data were analyzed using SPSS.17 and Chi-Square test.

In the present study, 91 general dentists (47.4%), 41 specialists (21.4%) and 60 dental nurses  (31.2%) participated. Their mean age was 32.58±7.22. The results showed that the majority of practicipants with knowledge (58.9%) and practice (74.5%) was moderate. Among these three occupational groups, there was no statistically significant differences observed in the level of knowledge (P-value =0.553) and practice (P-value = 0.679). The results revealed no statistically significant relationship between the level of knowledge and practice with age (P-value>0.05). There was statistically significant relationship was found between the level of knowledge, but not practice with gender (P-value=0.03).

Based on the results of this study, the level of knowledge and practices of the participants in regard with hand hygiene was moderate therefore, the promotion of the health care providers knowledge seems to be necessitated via holding workshops.

Today as the technology of dental product fabrication progress the demand for maximum esthetic of restoration increase، is sided of knowledge and usage of new ceramic in dental lab selection of proper type and color of cement and their effect on definition color of restoration is mandatory and error in this regard increase treatment cost. Thus the aims of this study were to evaluate the influence of resin cement and different thickness in zirkonzahn ceramic on the final color of the zirkonzahn ceramic crown by spectrophotometer.

In this invitro study ZirconzahnA2 disks were prepared with dimension 5mm diameter and      1.2 mm thickness Panavia F2 and zincphosphate cements was use as luting agent on the composite (Denfil A2) substructure. Ceramic zirkonzahn (0.3، 0.5، 0.7) mm was apply on the zirkonzahn core and the color changes in comparison to control group evaluate by easy shade II spectrophotometer. Data were analyzed with SPSS17, T-tests, and ANOVA statistical tests.

Shade of the cement had significant effected on the color of zirconzahn ceramic (P value=0.001).Various thickness of zirkonzahn ceramic have different color changes result on restorations (P-value=0.068).  

Cement used in a ceramic restoration (zirkonzahn) can affect the final color it in such a way that, in the absence of proper cement selection and inadequate thickness of the core, it is unacceptable in terms of color match and aesthetic restorations turn.