Journal of Dental Medicine

Background and Aims: One of the most important challenges for dentists is providing a crown with appropriate marginal fit and gap. The 135-degree tooth preparation found to have some advantages such as technical ease and appropriate finish line record. Despite the advantages of 135-degree tooth preparation, scant research has been done in this area. Therefore, the aim of this study was to compare 135-degree and deep chamfer tooth preparation on the marginal fit and marginal gap of posterior metal-ceramic crowns.
Materials and Methods: Deep chamfer and 135-degree tooth preparation were performed on the two first mandibular molars with healthy coronal tissue and similar size. Impression was taken from each tooth and 30 crowns were made on each die. The sample plastered with fit checkers were pressed under the force of 40 N for 3 min in a universal testing machine. They were measured and recorded under a loop with 40x power in three points on each aspect. Data were analyzed by Wilcoxon and Kolmogorov-Smirnov tests using SPSS version 24.
Results: The mean marginal fit values in deep chamfer and 135-degree were 48.5417µm and 55.3333 µm, respectively with no statistically significant difference (P>0.05). While the mean marginal gap in deep chamfer (2.4833 µm) was significantly higher (P<0.05) than 135-degree (1.0083).
Conclusion: It can be concluded that the marginal gap by 135-degree’s tooth preparation was lower than that of deep chamfer in metal-ceramic crowns. However, no significant difference in the marginal fit between the deep chamfer and 135-degree tooth preparation was found.

Background and Aims: Advances of genetic science in genomic techniques have led introducing new diagnostic systems to study the diseases or treatment efficacies. In this science, which named “Personalized Medicine”, human genetic structure is used for evaluation of the diagnosis, treatment, and prevention of disease. Regarding the limited number of studies regarding this issue in Oral & Maxillofacial diseases, this study was aimed to evaluate the benefits and challenges of this new area (Personalized Medicine) in dental treatments.
Materials and Methods: In this study, complete evaluation of abilities and challenges in order to apply the “Personalized Dentistry” in Dental treatments, and also its effect on oral health indexes were done. All the existing related articles were searched with the relevant key words in the scientific data bases of PubMed, Google Scholar, Medline, Scopus, SID and Magiran. Based on the inclusion and exclusion criteria, 5 articles were selected, assessed and summarized.
Results: In the evaluated articles, the benefits of “Personalized Dentistry” in dental treatments as targeted and specialized treatment could result in lower time, energy and cost. In addition, its disadvantage as unknown biologic effective factors and also, the cross effects of some of the above items on each other and the treatment procedures were mentioned.
Conclusion: Regarding the specialized sciences and diagnostic tools for oral & maxillofacial disease, the benefits of “Personalized Dentistry” application can be increased for special treatments of patients. Also, it could reduce the side effects of conventional therapies and thus, could be introduced as an effective step for better dental treatments.

Background and Aims: Erosion is the chemical dissolution of a tooth by acid without bacterial involvement. The purpose of the current study was to investigate the effect of resin infiltration (Icon), MI paste plus, and Nd:YAG laser on the enamel microhardness.
Materials and Methods: 40 enamel samples were obtained from the third molar tooth. Primary microhardness was measured in all specimens. Then, erosion was created using hydrochloride acid on the surfaces of enamel and the microhardness values were measured. The samples were randomly divided into four groups. G1: MI paste plus, G2: MI paste plus+ Nd:YA laser, G3: ICON without etching, G4: ICON with etching. Erosion was induced again by hydrochloric acid and then subjected to thermocycling. Finally, the microhardness of the samples was measured. Statistical analysis was performed using SPSS23 software, one-way ANOVA, multiple Tukey and T-test comparisons. P<0.05 was considered as a significant level.
Results: The microhardness increased in the third stage compared to the second stage in all groups, which was statistically significant (P<0.000). Also, the comparison of the increase of microhardness among groups, except second group with the fourth group, was statistically significant.
Conclusion: All the materials used in this study significantly increased the microhardness of the eroded enamel.

Background and Aims: Periodontitis is one of the most common causes of damage to the gums and retaining structures of the teeth. Matrix protein, a metalloproteinase, is known as intermediate collagenase and the enzyme collagenase fibroblast, which is encoded in humans by the MMP-1 gene. The aim of this study was to investigate 1G/2G polymorphism in the MMP-1 gene and its association with the periodontal disease in the Iranian patients.
Materials and Methods: In this study, 50 patients with periodontal disease and 50 patients were selected as the control group in Kerman city. DNA was extracted from a person's blood sample using a kit. The desired primers were controlled by the NCBI site. Then, with the Tetra arms PCR technique, the desired polymorphism was multiplied. In the next step, the samples were transferred to electrophoresis gel and examined. The results were analyzed with SPSS software using T-test or Squer Chi-(X²).
Results: The percentage of 1G/1G genotype in the patients group was 8% and for the controls group was 0%. The percentage of 2G/2G genotype for the patients group was 24% and for the controls group was 18%. In addition, the 1G/2G genotype frequency was 68% for the patients group, and for the controls group was 82% (P=0.83). The results of Tetra-arms PCR genotyping of the samples were confirmed by sequencing.

Conclusion: The findings indicated that in Iranian patients, MMP-1 -1607 1G/2G (rs1799750) was not significantly associated with periodontal disease. It is recommended to take more samples from different parts of Iran to confirm the results.

Background and Aims: The vertical growth pattern of the face depends on several factors. One of these factors can be the muscle strength of the jaw. Maximum occlusal force (MOF) can be considered as an index to measure the function of the muscles of the masticatory system. Despite the various studies, the relationship between the facial pattern and muscle function is still controversial. According to soft tissue paradigm theory, muscle can affect the shape and form of bones of the jaw, face and head. The aim of this study was to determine the relationship between the maximum occlusal force and head and face growth pattern in dental students of Shahed University in Tehran.
Materials and Methods81 dental students (40 males and 41 females) were participated. MOF was measured with a loadcell designed for this purpose, and the anthropometric points of the face and head were measured with digital caliper. Two-way ANOVA and Tukey HSD tests were used to determine the effect of facial and head patterns on the maximum occlusal force. Statistical analysis was performed by SPSS23.
Results: The mean MOF in males was 480 N and in females 320 N. Head forms in our sample research were 54.32% Brachycephale, 32.09% Mesocephale, and 13.58% Dolicocephale. The form of the face was 23.45% euprosopic, 39.5% mesoprosopic, and 37.03% leptoprosopic. According to the statistical analysis, the relationship between the maximum occlusal force and leptoprosopic form of face was statistically significant (P=0.02). However, there was not significant relationship between the maximal occlusal force and none of the three type of head forms (P=0.813).
Conclusion: MOF was related to the leptoprosopic pattern of face, and these individuals had less bite power. No relationship between the maximum occlusal force and head forms and neither between the head pattern and facial pattern was found in this study. The maximum occlusal force in men was higher in all three facial patterns than that of women, although this relationship was not significant.

Background and Aims: The inferior alveolar nerve block (IANB) is the most frequently used technique for mandibular anesthesia. Due to the many factors which can cause its failure, the aim of this study was to evaluate the efficacy of experience and knowledge in the success rate of IANB technique.
Materials and Methods: : In this study, 115 students of Shiraz Dental school were participated in two groups. One group contained 53 novice students and another group 62 students with one year experience in IANB injection. Each student accomplished injection once and then success or failure of the injection was examined. In order to evaluate the students’ knowledge, each student was asked to fill out a questioner including 6 questions related to the instruction of the injection. Data were then collected, coded, and analyzed by SPSS18 using Chi square with a significant level of 0.05.
Results: The rates of knowledge in novice and experienced group were 71.6% and 86.3%, respectively. The success rates of IANB were 47.1% in novice group and 64.3% in experienced group. The success rates of IANB and knowledge were significantly higher in the experienced group compared with the novice group. (P=0.02 and P=0.01, respectively) There was no significant difference between male and female (P=0.06).
Conclusion: The results showed that knowledge and experience could play an important role in the success rate of IANB technique.

Background and Aims: Some of the post-operative complications of impacted third molar surgery, one of the most prevalent surgeries in oral field, are known to be infection, erythema, trismus and pain. Antibiotic prescription to prevent post-operative infection under some particular circumstances, is acceptable but under debate considering their disadvantages. In the present study, we examined the infection rate in patients taking no or 2 types of antibiotics distinctively after impacted mandibular third molar surgery.
Materials and Methods: In this double blind clinical trial, 90 patients within the age range of 18 to 34 were dedicated to 3 groups (group 1: 2 capsules of placebo on surgery day and 1 for 4 days, group 2: Amoxicillin 500 mg every 8 hours for 5 days, group 3: Azithromycin 250 mg, 2 capsules on surgery day and 1 capsule for 4 days). All subjects were treated by a sole surgeon, protocol, surgical technique, and flap type and the same amount of osteotomy. In addition to aforesaid drugs, the patients received chlorhexidine and Gelofen 400 mg. At the day 7 postoperative, cases were examined to evaluate the infection (trismus, erythema and halitosis). Data were analysed using Chi-Square test and the groups were compared by Kruskal-Wallis test.
Results: Three signs of infection (halitosis, erythema and trismus) were compared in patients. Symptoms of halitosis and erythema were more indicated in first group, but the ultimate statistical analyses among the 3 groups from halitosis and erythema viewpoint showed no significant difference (P=0.072, P=0.149). Although, no severe trismus was reported, the most moderate trismus incidence was in group 2 and mild trismus was exhibited in group 1. In group 3, no trismus occurred. On the whole, the trismus frequency among groups was statistically significant (P=0.004).
Conclusion: Comparing infection symptoms of the three study groups emphasized the fact that only trismus rate was statistically significant (P=0.004). On balance, the results of this study indicated that antibiotics did not have significant impact on the reduction of most postoperative complications, especially on infection.

Background and Aims: Elastomeric chains are known as a current device with the purpose of dental movement in orthodontic treatments. The aim of this study was to compare the elastomeric behavior and force degradation rate between different elastomeric chains existing in Iran in different time durations.
Materials and Methods: 11 different elastomeric chains used in this study were: Class One, ASTAR, G&H, TSNPT, MIB (French and Chinese type), Ultra Chain and both American, Ortho Technology (simple and memory type). All chains were stretched upon to exert 150 g force and then force degradation rate in 6 time duration
(1, 3, 24 hours and 3, 7, 21 days) and modulus of elasticity (MOE) in 2 time duration (start and 21 days) were investigated. All Data were analyzed statistically by ANOVA, Tukey, Games-Howel tests.
Results: All chains up to the 21th day showed a significant decrease in MOE except for the G&H, ClassOne, simple orthotechnology and a significant force degradation except for the American (memory type). The most significant force degradation rate was in ASTAR gray (P<0.05) and the least in MIB (French), Ultra Chain, and American (P<0.05).
Conclusion: All chains showed significant time-dependent force degradation (mostly in the first day). Only, this rate was not significant in any time duration for the American (memory). In all groups, the most force degradation rate belonged to ASTAR gray and the least to Ultra Chain, MIB (French) and American after 21th day.

Background and Aims: Periodontal diseases are prevalent and are not only a threat to oral and dental health of patients and community, but also affect the quality of life associated with oral health. Therefore, the present study aimed to evaluate the effects of non-surgical periodontal therapy on the quality of life associated with oral health in patients with periodontitis and gingivitis.
Materials and Methods: 47 patients with gingivitis and moderate to severe chronic periodontitis referred to the periodontology department of Yazd Dental School in 2019 were studied. OHIP-14 validated questionnaire was used to assess the quality of life related to oral health. At the beginning of the study, both groups completed the questionnaire. Then scaling and root planning for periodontitis group and scaling for gingivitis group were done. Patients completed the questionnaires again 9-12 weeks after periodontal treatment. Data were analyzed by SPSS software version 22 using independent T-test, Chi-square, Mann-Whitney and Wilcoxon tests.
Results: The mean score of quality of life in patients with gingivitis was 19.18±11.68 before the treatment and 13.26 ±11.41 after treatment. The mean score of quality of life in patients with periodontitis was 23.29±9.80 before treatment and 13.95±9.68 after treatment. All the differences between groups before and after treatment were statistically significant (showing better quality of life after the treatment) (P<0.05). There was no statistically significant difference between the mean score of quality of life related to oral health in the studied patients according to the age and sex (P>0.05).
Conclusion: According to the results of this study, treatment of periodontal diseases improves quality of life related to oral health in patients with gingivitis and moderate to severe chronic periodontitis.

Background and Aims: Pre-cancerous lesions of the oral mucosa as important malformation need acceptable knowledge of dentists. The purpose of this study was to determine the knowledge of Isfahan city general dentists about pre-cancerous lesions of oral cavity.
Materials and Methods: This descriptive cross-sectional study based on validated questioner form was performed in 115 general dentists in Isfahan City in 2019, associated with sex and year of graduation from general dentistry course. The mean score was in the range from 0 to14. Data were recorded in Microsoft Excel and then analyzed by SPSS. In order to compare quantitative variables, independent T–Test, One-Way ANOVA and Mann-Whitney was used. P≤0.05 was considered as significant.
Results: The mean age in the participants of: lower than 5 years, between 5-10 years, and more than 10 years of graduation were 28.6±4.9, 30.6±4.0 and 47.9±10 years old, respectively. In total population, the mean score of knowledge was 5.97±2.79. There was not any significant difference between the mean score of knowledge in women when compared to men (5.96±2.99 versus 5.98±2.6; P=0.58). The mean knowledge score in the participants of: lower than 5 years, between 5-10 years, and more than 10 years, of graduation were as follow: 7.8±2.2 versus 5.8±2.9 versus 4.4±2.1, correspondingly (P≤0.05).
Conclusion: For the early diagnosis of pre-cancerous lesions of the oral cavity, retraining program based on oral cavity pathology courses is recommended for the dentists in Isfahan city.

Background and Aims: The self-adhering composites were introduced to reduce the chair time and minimizing handling errors. They can be bonded micromechanically to the dental structure without the need for separate adhesive application. Since there is limited information about bonding performance of this type of composite, the aim of this study was to evaluate the microleakage of enamel and dentin margins compared to the conventional adhesive systems.
Materials and Methods: 30 intact premolars were selected and on their buccal and lingual surfaces, standardized class V cavities with the occlusal margin in enamel and gingival margin in dentin were prepared. Then according to the materials used, the specimens were randomly divided into three groups including: 1) Vertise flow, 2) SE bond + ValuxTM Plus, and 3) Single bond + ValuxTM Plus. After final polishing of the restorations, the specimens were subjected to 1000 thermal cycles of 5±2 and 55±2°C and after that dye penetration was examined by stereomicroscope. The collected data were statistically analyzed using Kruskal-Wallis test and Mann-Whitney test
Results: The lowest rate of the occlosal microleakage was related to group 2 (P<0.05) and there was no significant difference between groups 1and 3 (P=0.58). Also, no significant difference was found in the gingival microleakage among the three groups (P=0.23). On the other hand, in each group, the gingival microleakage was significantly higher than occlosal margins (P<0.05).
Conclusion: According to the results, sealing ability of self-adhering composite is comparable with that of the conventional adhesives.

Background and Aims: Different materials have been used to make dentures during different years. Teeth used in making dentures should have appropriate physical and mechanical features to meet the needs of masticatory functions, meanwhile having desired beauty. The aim of the present study was to determine the frequency of previous denture material and f its form and the duration of use in patients referring to the prosthesis department of Tabriz Dental School during 1385 to 1395.
Materials and Methods: This cross-sectional descriptive study was performed on the basis of paraclinical examination on all cases of removable prostheses in patients referring to the department of prosthodontics of Tabriz University of Medical Sciences from 1385 to 1395. Based on the files, the percentage of frequency of previous denture type, previous denture tooth material, previous tooth form, previous time of denture using during the day and night were statistically evaluated by SPSS20 software.
Results: The results of this study showed that out of 471 patients, 151 people used removable dentures. A study of previous denture material showed that the frequency of using dentures containing resin teeth with 48.3% was much higher than porcelain teeth with 13.8. Examination of the dental form showed that in 13.8%, the dental form was with a cusp, in 48.3% without a cusp and in 37.9% the type and form of the teeth were not clear (P<0.01). Evaluations showed that 24.1% of patients used their dentures only during the day and 41.4% of patients used them overnight.
Conclusion: A 10-year study of patients with dentures at the Tabriz School of Dentistry documented the common use of resin teeth denture, as well as overnight use of them and the non-cusp form of denture teeth.

Background and Aims: Anxiety is a common problem in patients referred to dental clinics that is associated with underlying personality factors. The purpose of this study was to determine the role of personality traits in predicting dental anxiety.
Materials and Methods: In this study, 211 patients (110 men and 101 women) referred to the dental clinics in Tabriz in 2019, were selected by available sampling method. The method of this study is descriptive- correlative. The research instrument was a short-form NEO-personality inventory and a dental anxiety inventory. Data were analyzed by correlation and regression analysis using SPSS22.
Results: The research findings showed that the average age of women and men was 30 and 31 years, respectively. 49% of the clients were single and 51% were married, and the education of most of the clients was undergraduate. Also, Regression analysis showed that dental anxiety had a positive correlation with personality trait of neuroticism (r=-0.49, P<0.01), and it had a negative relationship with extroversion (r=-0.19, P<0.05), agreeableness (r=-0.21, P<0.01), consciences (r=-0.35, P<0.01); and two factors of neuroticism (t=4.71, P<0.01) and conscience (t=2.44, P<0.01), and predicted dental anxiety (P<0.05).
Conclusion: From the results, it can be concluded that anxiety with a sense of danger that was observed in many people in the face of dental interventions, occurred within individuals. By recognizing root factors, it can be partly strengthened by deterrent and suppressor personality factors for anxiety, and thus, taking advantages of the dental services and preventing from avoiding dental treatments.

Background and Aims: Interest and satisfaction of students toward their field of study has important role in knowledge promotion, future activities, and also healthcare of country. This study aimed to evaluate the attitude of dental students toward their field of study and also their future career.
Materials and Methods: This cross-sectional descriptive study was based on a standardized researcher designed questionnaire in 2018. Demographic data was collected and questions were based on the attitude of students toward their field of study and their future. ANOVA and Backward stepwise regression methods were used for statistical analysis. Significance level was determined at 0.05.
Results: In this study 62.2% of responders were female and 37.8% were males. Students chose dentistry under the influence of following matters consecutively: high income, recommendation of people around and self-interest. Girls compared to boys, were significantly influenced more by self-interest and also had more interest compared to boys for working in dentistry (P<0.05). Also, most of students were anxious about the increase in the number of dental students.
Conclusion: Students had positive attitude toward their field of study and their future. They were interested in working in this field but factors such as not having enough familiarity toward this field and also an increase in the number of students in recent years created some worries for them.

Background and Aims: Adding nanoparticles to dental composite resins, could reduce bacterial adhesion and secondary caries. Thermocycling can resemble in-vitro conditions to the oral environment. The aim of this study was to determine the effect of thermocycling on the microleakage of a mixture of copper oxide nanoparticles and flowable composite.
Materials and Methods: In this in-vitro study, 88 premolar teeth were divided into eight groups based on the application of copper oxide nanoparticles with concentrations of 0.1% and 0.3% w/w and thermocycling by 0, 1000, 5000 and 15,000 cycles. The occlusal grooves of the teeth were sealed with the mixture of flowable composite and copper oxide nanoparticles, and the teeth were thermocycled. Next, the teeth were immersed in methylene blue 2% solution for 24 hrs and were cut and the microleakage was evaluated by a stereomicroscope (hp/USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney tests at the significance level of 0.05.
Results: In the groups with 0.1 % copper oxide nanoparticles, the mean microleakage increased significantly with increasing the number of thermocycling rounds (P=0.032). The difference in the microleakage between the groups exposed to 0 and 15,000 termocycling was significant (P=0.019). However, thermocycling had no significant effect on the microleakage of groups with concentration of 0.3% (P=0.780). The specimens subjected to the 0, 1000, 5000 and 15000 thermocycling in two concentrations of copper oxide nanoparticles showed no significant difference in the microleakage.
Conclusion: In groups containing copper oxide nanoparticles with a concentration of 0.1%, the microleakage increased by increasing the number of thermocycling up to 15,000 cycles compared to the control group. However, this did not have significant effect for the concentration of 0.3% copper oxide nanoparticles.

Background and Aims: With increasing age and inability to maintain good oral hygiene, the chances of tooth loss increase and the need for dental implants will increase in the future. It also increases the risk of developing peripheral implants, especially at older ages in the failure of implant treatments. Recently, the high prevalence of cardiovascular disease and peri-implantitis in the elderly has been reported. The aim of this study was to investigate the effect of cardiovascular disease on the peri-implantitis in people with failed dental implants.
Materials and Methods: In this retrospective study, the files of patients referred to Shahid Montazeri Dental Clinic from 2009 to 2018 whose their failed implants were extracted, were collected. There were a total of 793 people with failed dental implants. The variables of this study were demographic information including age and sex, health status in terms of cardiovascular disease and peri-implantitis, which were identified and then statistically analyzed by examining the files of patients with these two variables. Data were statistically analyzed by SPSS25 statistical software and Chi-square was used to determine the effective variables.
Results: A total of 793 patients had failed dental implants, including 368 women (46.4%) and 425 men (53.6%) with an average age of 50.79 years. 42 patients (5.3%) had heart disease and 44 (5.5%) had peri-implantitis. According to the Chi-squared test, the significance level was less than 0.05 (P=0.011).
Conclusion: The results of this study showed that the cardiovascular disease and peri-implantitis were significantly related.

Background and Aims: Providing quality services is one of the important goals of the health system. Dental services and treatments are expensive. The aim of this study was to investigate the factors influencing the perceived quality of dental treatment services.
Materials and Methods: This descriptive-cross study conducted in 2 qualitative-quantitative phases. Data were collected using interviews and pairwise comparison matrix with 20 dentists working in NAJA dental clinics who were selected by targeted sampling. The validity and reliability of the interviews were determined by long-term engagement of their peers and negative case analysis. The validity of the pairwise comparison matrix was determined through the incompatibility rate (>0.1). Data were analyzed by coding and effect intensity tests (R+J), descriptive statistic test (mean, standard deviation) using SPSS23, Maxqda and matlab R2017b.
Results: Content analysis of the interview showed that tangible factors, assurance, trust, and empathy are the factors affecting the quality of dental treatment services. In the second phase, data analysis showed that trust and empathy (28.204), assurance (24.356), and tangible factors (17.798) are the most to the least important factors in the quality of dental treatment services (P=0.1).
Conclusion: Trust and empathy were the most important factors in the quality of dental treatment services. Managers of dental clinics and dentist need to improve the quality of dental treatment services by emphasizing respect for patients in accordance with the promise to act in the field of providing treatments to patients.

Background and Aims: Human ergonomics or engineering with proper design and change of work and requirements creates the most productivity based on human physiology. The purpose of this study was to determine the level of awareness of dental students of Isfahan University of Medical Sciences about the basic principles of ergonomics in dentistry.
Materials and Methods: In this descriptive-analytical, sectional study, a questionnaire containing 10 questions was distributed and completed by easy sampling method among 74 final year students of the general doctorate of Isfahan school of dentistry. After collecting the questionnaires, the students were given an educational pamphlet. To evaluate the questionnaires, each correct answer was given a score of one and the wrong answers were given a score of zero. Data were analyzed by T-test, Kai Square, and Mann-Whitney statistical tests using SPSS23 software. P<0.05 was considered as a significant level. P<0.05 was considered as a significant level.
Results: The average score of the knowledge of principles of ergonomics was intermediate (6.23±1.25). Student knowledge was not significantly different based on the student gender (P=0.25) and academic semester (P=0.059). Also, 55% of students had a history of muscle pain that did not have a significant relationship with gender (P=0.258) and average score of the knowledge (P=0.288).
Conclusion: Unfortunately, ergonomics cannot be considered part of the principles of dental education and even later. Musculoskeletal pain is one of the most common complaints of dentists and is a factor in reducing their quality and function. Therefore, it seems that training and evaluation of ergonomic principles in dental education is necessary.

Background and Aims: Pulpal exposures originated from the external cervical root resorptions have major effects on the treatment and prognosis. Therefore, the aim of this study was performed to compare the two different imaging systems-digital radiography with PSP (Photostimulable Phosphor) sensor in three horizontal different views and CBCT (cone beam computed tomography) images to assess the pulpal exposure in simulated cavity of external cervical root resorptions that was performed in 1398 in the School of Dentistry of Azad University.
Materials and Methods: 40 intact maxilla anterior teeth with straight roots were included. Teeth were randomly divided to two groups (20 teeth with and 20 without pulpal exposures). Each sample was assessed using PSP digital radiography (in 3 horizontal angles) and CBCT image system, to detect the presence of pulpal exposures. False negative and false positive results in 2 imaging procedures were judged with ratio test.
Results: The results showed in CBCT (P.P.V=85.7%) and (N.P.V=89.5%), and in digital intraoral radiography (P.P.V=80%) and (N.P.V=80%) in proximal defects. Ratio test showed that there were no significant differences in the proximal defects (P<0.4).
Conclusion: The results showed that there were no significant differences in detection of exposure in the proximal surfaces between two imaging systems.

Background and Aims: Periodontitis is an inflammatory multifactorial disease in oral tissues and many genetic reasons and environmental factors responsible. Vitamin D deficiency has been determined to be related to periodontal disease. This aim of this study was to investigate the association between rs7975232 polymorphism in vitamin D Receptor gene and periodontitis in 100 patients (as patient and control groups).
Materials and Methods: Blood samples from 50 patients and 50 control groups were selected and DNA from the samples was extracted by the DNA extraction kit. Genotyping was used by Tetra Arms-PCR method. The use of sequencing was confirmed by the Tetra Arms-PCR genotyping results. Then, statistical analysis was performed using SPSS statistics 20 software and T-test.
Results: Frequency of AA, AC, and CC Genotypes were 25 (50%), 14 (28%), and 11 (22%) in patients’ cases, and 26 (52%), 16 (32%) and 8 (16%) in controls, respectively. AA genotype was the highest genotype between the patient and control groups. Statistical analysis showed no significant association between this type of polymorphism and periodontitis disease in the studied samples (P=0.67).
Conclusion: This finding showed there was not significant association between rs7975232 polymorphism in vitamin D Receptor gene and periodontitis disease in the studied samples. To confirm the results of this study, further studies with large sample size and different types of population are recommended.