نشریه تحقیقات دندانپزشکی
سال سوم شماره 1 (پیاپی 3، بهار 1393)

In recent years, the elderly people proportion in our community has increased due to the better public health accessibility and longer life expectancy. Oral health status of the elderly has a profound impact on their quality of life and social relationships. The aim of this study is to assess the frequency of dry mouth and burning mouth without any clinical signs between elders over the age of 65 in nursing homes in yazd province.

This descriptive cross-sectional study was conducted on 225 institutionalized elderly from Sep 2012 to Aug 2012 in Yazd province. Dry mouth and burning mouth incidence were examined via applying a questionnaire and clinical procedures. Systemic disease background and history of medications usage were derived from the participant’s hospital records. Statistical analyses were performed using SPSS (versions 17) applying chi-square statistical test to compare variables and the significance level was set at 5% (p<0.05).

Eventually 225 elderly were selected, among which 9 cases were excluded due to lack of owning consistent criteria of the study. 61.1% (132) participants were females and 38.9% were males, whose age range and average were 77±3 and 65-91, respectively. In this study, a significant relation was observed between the frequency of dry mouth and the gender (p=0.02), though no statistically significant relation was observed between burning mouth incidence and the gender (p=0.16).

Based on the study findings, it seems that dry mouth and burning mouth involve prevalent disturbing problems within the elderly. However, other studies are necessitated to achieve more accurate results.

Impacted tooth may be associated with various complications, among which cysts and tumors of jaw can be mentioned. As a matter of fact, neoplastic or cystic changes can occur in surrounding tissues of impacted tooth. Therefore, the present study was accomplished aiming to determine the relative frequency of pathologic lesions associated with impacted teeth in pathology reports of Yazd dental school in 2000-2011.

In this descriptive cross-sectional study, 1121 samples available in the archive of Pathology department of Yazd dental school were examined by census method. The samples were related to the patients recorded within recent 10 years (1380-90) who had impacted teeth accompanied with cystic and tumoral lesions. Moreover, the study data were analyzed by SPSS (ver.16) applying Fisher's exact test.

In this study, among 50 lesions related to impacted teeth, 38 cases (75%) were cysts and 12 cases (25%) were tumors. The most common lesions observed, were Dentigerous Cyst in the first place (64%) and then Odontogenic Kerato Cyst (48%) in the second place. The occurrence of these lesions within males (68%) was reported higher than that of females(32%) and it was mostly observed in the age group of 20-46 (60%). Furthermore, the most common location of engagement was posterior mandible (70%).

The results of the current study revealed a significant association of pathologic lesions with impacted teeth in the studied population. Therefore, surgery treatment for impacted teeth with follow up and evaluation of the surrounding tissues seem to be necessitated.

Increasing of age in adults is normally accompanied by some levels of decreasing in life quality, however, we cannot ignore the effect of other variables like tooth loss. Therefore, the present study was conducted aiming at determining the life quality in patients with denture, who referred to the prosthesis department of Yazd dental school in 2012.

In this descriptive- analytical study, 117 patients who referred to the prosthesis department of Yazd dental school were chosen by the simple random sampling. The required data were collected by using a valid and reliable questionnaire. The data were analyzed by SPSS (ver.17) applying ANOVA, T-test and Pearson's correlation coefficient.

In the present study, 117 patients, aged 31-74, participated among which, 44 (37.6%) were males and 73 (62.3%) were females. The range of using denture was 1 to 5 years. The average score of life quality in all aspects revealed a statistical significance in regard with age and duration of using denture (P.value< 0.05). According to the results of Pearson test, all the aspects of life quality had a positive and significant relationship with each other.

The study results revealed that the people who used denture less than the others had a higher score of life quality. Moreover, it was demonstrated that life quality decreases with increasing patients’ age.

The irrigators utilized during root canal preparation can change the surface structure of dentin, which this effect has been reported differently in different studies. Therefore, the irrigators can interfere with bond strength or resin composite attachment to dentin and as a result, some problems may arise. The aim of this study was to evaluate the effect of root canal irrigator on the microtensile bond strength of self-etch adhesive system and composite.

In this laboratory trial, sound extracted human third Molars were utilized. After providing access cavity, the teeth were divided randomly to 6 groups based on type of root canal irrigators (Normal saline,Naocl5.25%,CHX2%) and time interval(5,30 min). The teeth were restored with clearfil SE bond adhesive resin system and Z250 composite in 1.5 mm thickness layers. Three Bucco-Lingualy sections in 1mm thickness were made for each tooth. The specimens were submitted to the micro tensile test in Micro Testing Machine at a crosshead speed of 0.5 mm/min in order for the fracture to be caused. The study data were analyzed utilizing SPSS18 software via Kruskal-wallis, Man-witney, ANOVA tests.

The results of the present study proposed that the type of root canal irrigator in different time interval did not show any significant effect on microtensile bond strength of adhesive system(Ptime=0.729,Pmaterial=0.153). Moreover, the obtained results demonstrated maximum and minimum microtensile bond strength for normal saline(44.13 N) and Naocl5.25% (31.29 N) respectively.

The study findings indicated that the type of root canal irrigator as well as different time intervals did not show any significant effect on microtensile bond strength of adhesive system.

It is possible to spread pathogens while working with ultra-sonic device through aerosol's dispersion so, it is necessary for dentists to have knowledge about infection control and the way of using it . this study was accomplished with the aim of evaluation of level of student's awareness of Yazd dental school about contamination during working with ultra-sonic device in the year 2012-2013

In this descriptive-sectional study, 80 students of Yazd dental school, which had passed periodontics, were included by census method. In order to evaluate the level of students’ knowledge about the possibility of infection's spread by working with ultra-sonic device and the way of controlling it, a questionnaire was used which consisted of 12 questions and its validity and reliability was confirmed. The data were analyzed by SPSS ver.17 and T-test.

From 80 students 43 were female (53.75%) and 37 were male (46.25%). The most correct answer was related to the sentence "mandatory of disinfecting the room which scaling has been done in". the average students score about the possibility of infection spread during working with ultra-sonic device and the way of controlling it was 6.76±0.620 that was evaluated in a moderate level. There was not a significant difference in the level of knowledge (P.value=0.062), however, female students awareness was more than male students.

According to the moderate level of students’ knowledge about infection control during working with ultra-sonic device, it is recommended to provide more education in this field.

Occurring medical emergencies in dental clinic is rather prevalent and thus, a dentist must be well prepared to recognize and deal appropriately with such situations. Therefore, this study aimed to evaluate the level of Yazd general dentist’s knowledge in regard with medical emergencies in 2013.

This descriptive cross-sectional study was accomplished on 85 general dentists of Yazd via simple random sampling. The study data was gleaned by a valid and reliable questionnaire consisting of demographic features plus 12 knowledge questions (score 10-12: perfect, 7-9: good, 4-6: moderate, below 4: weak). The gathered data was analyzed by SPSS software (ver.18) applying Pearson’s correlation test and T-test.

The average knowledge score of dentists was 7.16 ± 1.69 out of 12, the average number of emergency drugs was 4.58 ± 1.88, and the average number of emergency appliances was 2.85 ± 1.61 calculated within range of 0-8. The relationship between the dentists’ knowledge, age (p=.004 , r=0.31) and academic year (p=0.004, r=0.3) was proved to be significant, though no significant statistical difference was observed between dentists’ knowledge and gender (p=0.11) as well as participating in educational workshop (p=0.58).

It seems that dentists’ knowledge level in regard with medical emergencies is not favorable. Hence, it is recommended to pay a special attention to this issue within their academic period for a better and more effective education. Moreover, interventions are necessitated to be accomplished through holding educational workshops and constant training programs in order to upgrade and update their knowledge. It is worth mentioning that medical drugs and equipments seem to be insufficient for dentists. Therefore, it makes it difficult for dentists to manage medical emergencies.

This study was conducted to determine the prevalence and variations of pneumatized articular eminence in patients referring to Yazd Dental school.

A total of 3098 panoramic radiographs were retrospectively investigated for the prevalence and radiographic features of PAT. Chi-square and Fisher exact tests were utilized via applying SPSS software to analyze the research data .

Generally, PAT was found in 64 (2/1 %) patients. In other words, bilateral PAT was found within 24 patient (37 %), whereas unilateral PAT was found in 40 patient (63%) and thus, there was a statistically significant difference between bilateral and unilateral PAT (p=0.049). PAT occurred in 41 cases out of 1735 females (2/4%) and 23 cases out of 1363 males (1/7%), though no statistically significant differences were seen in regard with participants’ gender(Exact probability one side=0.117). Moreover, PAT was observed more in the age group above 50 years old (2/4 %) and less in ages between 40-49 years old. The ratio of unilocular pattern to multilocular pattern was 1/25.

The presence of PAT can be a contraindication for performing eminoplasty and eminectomy in order to treat recurrent chronic mandibular dislocation during the operation. Therefore, care must be taken while using burs in order to avoid such unwanted accidents as sudden penetration.

Impacted third molar surgery is followed by inflammatory reactions which can cause pain, swelling and trismus. Therefore, the present study was accomplished aiming to determine mouth opening limitation after mandibular third molar surgery in patients referring to the oro-facial surgery department of Yazd dental college within the academic year of 2012-2013 .

In this descriptive cross-sectional study, 63 patients participated who were suffering from impaction of mandibular third molar. The pre and mid operation factors were logged in a checklist. Maximum mouth opening, according to the space between anterior maxillary and mandibular teeth, was measured before and during the operation in time ranges of 1, 3 and 7 days with Vernir caliper. The study data were analyzed via SPSS software (ver.17) applying T-test.

In the present study, 63 patients participated who were 22 males (34.92%) and 41 females (65.08%) aged 18-30 years. Maximum mouth opening was significantly more on the seventh day than the third day in regard with lower age group(18-22), males, teeth with distoangular position, operation duration more than 30 minutes and duration of healing more than 12 days. (P< 0.001)

According to the results of the current study, mouth opening limitation on the first, third and seventh day of operation revealed a significant relationship in regard with sex, tooth location, surgery duration and healing period.