Journal of Dental Medicine

Normal 0 false false false EN-US X-NONE AR-SA Two Root coverage methods of free gingival graft method (FGG) and coronally positioned flap (CPF) by using citric acid were evaluated in anterior mandibular labial site of 16 patients. The measurements were done before first FGG surgery, after FGG and two months following the second surgery. The results showed 1% improvement of root coverage after surgery while in two stage CPF method by using citric acid, significant effect of citric acid was obtained. The width of Keratinized gingiva changed to 6.25mm from 1.18mm which was statistically significant.

Background and Aim: Intrabony periodontal defects are important problems in periodontology and up to now several ways have been suggested for their treatment .Treatment with enamel matrix derivatives (EMD) has been shown to enhance periodontal regeneration. There is limited information available from clinical trials regarding the performance of EMD in the treatment of periodontal intrabony defects. This study was designed to compare the clinical and radiographic effects of EMD treatment to that of open flap debridment (OFD) for two and three walled intrabony defects.

Materials and Methods: 18 patients were included in this clinical trial which have 24 two and/ or three intrabony defects. Defects were randomly divided into two groups (test and control). Defects in test group were treated with flap surgery plus EMD and in control group with open flap debridment. At baseline and at 3 and 6 months follow up, clinical and radiographic measurements were performed. Data were analyzed using Greenhouse-Geisser test with p<0.05 as the limit of significance.

Results: At 3 and 6 months, mean probing pocket depth reduction was greater in the test group (EMD) (4.33 mm and 4.70 mm) compared to the OFD group (2.54 mm and 3.09 mm). Mean values for clinical attachment gain in the EMD group after 3 and 6 months were 4.29 mm and 4.98 mm, and in OFD group were 2.83 and 2.82 mm respectively. Radiographic bone gain measured by radiovisiography technique was greater in the EMD group compared to the OFD group (4.66 mm in EMD and 1.11 mm in OFD group after 3 months and 5.78 mm in EMD and 1.39 mm in OFD group after 6 months).

Conclusion: Based on the results of this study, treatment with flap surgery and EMD compared to open flap debridment, produced more favorable clinical improvements in two and three walled intrabony defects.

Background and Aim: The use of fiber reinforced posts in endodontically treated teeth has become increasingly common. But their retention in root canals must be considered seriously. The aim of this study was to evaluate the effect of light-cure and dual-cure bondings on regional bond strength of a fiber composite post.

Materials and Methods: In this experimental in vitro study, 20 endodontically treated teeth were randomly divided into two groups. In the first group, a dual-cure bonding (Scotchbond Multi-Purpose Plus, 3M ESPE/USA) [SBMP] was used and in the other group, a light-cure bonding (Single Bond, 3M ESPE/USA) [SB] was applied according to the manufacturer's instructions. A dual-cure resin cement (Rely X ARC, 3M ESPE/USA) was used to cement the post (Glassix, Harald Nordin SA,Switzerland). Coronal 8mm of cemented posts were sectioned in equal thirds using a 0.1mm diamond disc. Each slice was polished by a soft and wet abrasive paper in order to get a 2mm thickness. Loading was performed by a testing machine (Zwick/Germany) at a speed of 1mm/min until the post was dislodged. Data were analyzed using one-sample Kolmogorov-Smirnov, T and ANOVA tests with P<0.05 as the level of significance.

Results: There was a significant difference between the two adhesive systems in the middle third of the canal block with higher bond strength in SBMP group (p=0.02). In SB group the bond strength of the cervical region was higher than the middle and apical thirds (p<0.05). In SBMP group, there was no statistically difference between bond strength of the three regions (p=0.117).

Conclusion: Based on the results of this study, dual-cure bonding could be recommended for composite post cementation into root canals, because its bond strength was more uniform in different regions of root and greater in the middle and third regions.

Background and Aim: Because of stable aesthetic and minimum destructive technique, Porcelain laminate veneer has an important role in aesthetic dentistry. But main reason of failure in this treatment is restoration fracture. Therefore tooth preparation have an important role in fracture resistance of porcelain laminate veneer. The aim of this in vitro study was to evaluate the fracture resistance of porcelain laminate veneer dependent on tooth preparation after exposure to dynamic loading.

Materials and Methods: In this study, 30 caries free mandibular incisors were devided into 3 groups. First group (Control group) remained unprepared. In second group (Window preparation) facial surface was prepared with 0.3, 0.5, 0.7 mm in cervical, middle and incisal, respectively. In third group (Incisal lap preparation) the preparation was like second group and included 2 mm of incisal edge. 20 feldespatic ceramic veneer were bonded adhesively with dual-cure luting cement (Rely X). All specimens were subjected to cyclic mechanical loading (720000 cycles, 1.3Hz, 30N) and thermal cycling (5-55 C, dwell time 60seconds, 500 cycles). The specimens were exposed to Universal testing machine until failure occurred with a constant crosshead speed of 1mm/min.

Results: Five specimens of first group, one specimen of second group and two specimens of third group fractured during cyclic loading. The mean failure loads(MPa) after exposure to continues load were as follows: First group: 168/96 (561.01-1115.08), second group: 394.10 (248.92- 641.33) and third group: 273.47 (135.45 - 479.80). Data analysis was performed by ANOVA, LSD and chi Square test.

Conclusion: Significant difference between 3 groups were found. Fracture resistance of control group was significantly higher than other groups and window group preparation was significantly higher than incisal lap group. The samples were under the cyclic loads before they put under the continuous pressures of universal testing machine. It was clear that incisal lap preparation is more resistance against fatigue failure compared to window preparation.

Background and Aim: At the end of fixed orthodontic treatment, enamel damages are affected by amount of adhesive remnants. Thus, determining the factors involves in the amount of adhesive remnants e.g. the types of resins and the methods used for debonding is of necessity. The aim of this study was to evaluate the effect of the composite resin type and debonding pliers on enamel surface by a new method in measuring the adhesive remnant.

Materials and Methods: In this interventionally in-vitro study, 120 extracted human premolars were randomly divided into four groups of 30 each. The standard edgewise metal brackets were bonded on the teeth with two pastes self-cure composite "Concise" in the first and second groups, and with No-mix composite "Unite" in the third and fourth groups. the debonding was done by means of Lift off Debonding Instrument "LODI" (3M-Unitek), in first and third groups, and Bracket Removing Plier (Dentaurum), in the second and forth groups, respectively. After debonding, all teeth were evaluated with steriology software (stereolith version 1) for comparing the amount of adhesive remnants between the four groups. For data analysis, One-way ANOVA and independent t.test were used.

Results: The fourth group showed the lowest adhesive on the enamel surface and the most on the bracket surface with significant differences with other three groups (p<0.01).

Conclusion: The use of Dentaurum debonding plier with shear-peel force when used with the Unite adhesive (group 4), would decrease the adhesive remnants on the enamel surface.

Background and Aim: The microbial cause of dental caries has been proved among its multifactorial etiologies. The prevention and control of dental caries is very critical because of high prevalence and cost especially in high risk patient such as xerostomia. Based on the world attraction to traditional treatment and importance of drug extraction of natural materials and plants, in this in vitro study effect of hydroalcoholic extract of Salvia officinalis and Pimpinella anisum which were very useful in traditional treatment of mouth and teeth disease has been determined against cariogenic bacteria.

Materials and Methods: In this experimental study, hydroalcoholic extracts have been prepared from Salvia officinalis and Pimpinella anisum with maceration method. Their antibacterial activity against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus have been evaluated with broth macrodilution method. Data were analyzed with Mann-Whitney test.

Results: Minimum Inhibitory Concentration for Salvia officinalis and Pimpinella anisum for streptococcus mutans were respectively 6.25 and 12.5 µg/ml, for Lactobacillus rhamnosus were 1.56 and 12.5 µg/ml and for Actinomyces viscosus were 12.5 and 50 µg/ml.

Conclusion:Both extracts had growth inhibitory effect on all three bacteria. Salvia officinalis had significantly greater effect on inhibition of growth of all three bacteria. Both extracts had bactericidal effect in the range of concentration.

Background and Aims: Since there is a relationship between the tooth size and race, it seems that having statistical information about the tooth size in a society in which the orthodontic treatments are done, is very important. The aim of this study was to determine the relationship between the mesiodistal width of permanent incisors and first molars in both jaws with unerrupted permanent canine and premolars. New regression equations for prediction of the sum of mesiodistal width of canine and premolars were established.

Materials and Methods: A total of 715 dental casts (526 female, 189 male) were recruited from the department of orthodontics of Shiraz dental school and private offices of orthodontists for this cross sectional study. The greatest mesiodistal widths of all teeth were measured with digital caliper with accuracy of 0.01 mm. All data were analyzed with SPSS software and Pearson Correlation, independent T-test, paired sample T-test and multiple linear regression tests.

Results: Tanaka-Johnston equations and Moyer’s prediction tables had significant difference with mesiodistal dental width of south Iranian population, so new regression equations (based on incisors and first molars) for different jaws and sexes were presented in this study for south Iranian population. The best suggested regression is the regression that is based on all maxillary and mandibular incisors and first molars and has 12 variables. The suggested regression for prediction of maxillary canine and premolars based on the summation of mesiodistal width of all incisors and first molars in both jaws was Y=0.177X+4.227 and for prediction of mandibular canine and premolars was Y=0.188X+2.730, which a the greatest in r2 prediction of unerrupted teeth in comparison with the regressions based on incisors alone or incisors and first molars in one jaw.

Conclusion: Tanaka-Johnston and Moyer’s prediction tables are overestimated the actual size of south Iranian’s teeth width. So new regression equations based on incisors alone and incisors and first molars are suggested to increase the accuracy of space analysis in both jaws.

  Background and Aims: Orthodontic patients’ cooperation is a determining factor in treatment outcomes. The aim of this study was to evaluate the relationship between patient cooperation during orthodontic treatment with variables such as age, sex, life setting, treatment duration and functional and social discomfort experienced.

  Materials and Methods: Specimens were consisted of 100 orthodontic patients (36 males and 64 females) between 13-35 years old (average age: 22.57±1.69 years). Patients’ demographic traits, treatment duration and
functional-social discomfort by the orthodontic treatment were evaluated using a questionnaire answered by the patients or their parents. The degree of patient cooperation was assessed by the modified cooperation questionnaire (Orthodontic Patient Cooperation Scale [OPCS]) which was completed by an orthodontist. Data were analyzed using One-way ANOVA, T-test, intraclass correlation coefficient and Pearson Correlation.

  Results: No significant difference was found between the cooperation of male and female patients (P=0.867) and also between the cooperation of the patients who lived in the urban and rural setting (P=0.613). Treatment duration and compliance showed a low negative correlation which was not statistically significant (r=-0.155, P=0.127). Functional-social discomfort and compliance showed a low negative correlation which was not statistically significant (r=-0.118, P=0.244). No significant correlations were found between the compliance and age (r=0.002, P=0.988) and also the treatment duration and functional-social discomfort experienced
(r=0.164, P=0.105).

  Conclusion: Patient compliance appears to be a complex issue that cannot easily be predicted only by factors such as age, gender, life setting, treatment duration and functional-social discomfort experienced.

  Background and Aims: Dental caries is one of the most common infectious diseases which could be prevented in various ways. The aim of the present study was to evaluate the effect of a toothpaste containing different concentrations of nano-hydroxyapatite on the remineralization of incipient caries.

  Materials and Methods: 9 sound first premolar teeth of maxilla and mandible were sectioned to four pieces. 6 specimens were stored in distilled water as control group. The remaining 30 specimens were demineralized for 72 hours and then their microhardness was measured. 0, 0.5, 1, 2 and 5% wt nano-hydroxyapatite were added to the solution of distilled water and toothpaste. Specimens were divided into 5 groups (N=6) and after demineralization, each group were randomly immersed in the above-mentioned solutions for 15 minutes. Next, specimens were kept in artificial saliva for 1 hour followed by immersion in the related remineralizing solution for another 15 minutes. This procedure was repeated for 5 days. Finally, the microhardness of the teeth was measured. Data were analyzed using repeated measures analysis of variance (ANOVA).

  Results: The microhardness of demineralized teeth was increased following exposure to different concentrations of nano-hydroxyapatite, but this increase was not statistically significant (P=0.62).

  Conclusion: Nano-hydroxy apatite can enhance remineralization and increase the tooth microhardness although this increase was not significant.

  Background and Aims: The aim of this descriptive longitudinal study was to determine the type of teeth that were more prone in accidental bracket debonding and also to investigate the relationship between broken bracket bond and intervening factors such as age, type of malocclusion and sex.

  Materials and Methods: We used a pilot study to determine the correct sample size for this study. According to the pilot study which consisted of 20 records of patients, it was concluded that 576 patient’ records was needed. The mean time for a bracket before it fails was also measured using Kaplan-Meier method. Cox regression analysis was done to examine the effect of age, gender, and class of malocclusion on each tooth with broken bracket. Data were analyzed using the software SPSS 20.

  Results: Results showed that the percentage of unexpected broken bracket bond for each tooth varied and they were significantly related only in second premolars in both jaws with malocclusion that was different for each tooth (P=0.037, P=0.004).

  Conclusion: Maxillary second premolars and mandibular second premolars had the highest rate of unexpected broken bracket bond in CL II CL I malocclusion respectively. Age, gender and malocclusion had no effect on the unexpected broken bracket bond for other teeth.

Background and Aims: With the advancement of technology, the use of old teaching methods has been replaced by new and more efficient methods such as podcasts, to save the time of students and professors and to provide the opportunity for these two groups to interact more with be given to each other in the classroom. This method has advantages such as lower cost, the possibility of content courses, downloading content, and learning courses remotely. This study aimed to investigate the other benefits of this method as well as the level of students' satisfaction.
Materials and Methods: In this study, which was a randomized, single-blind educational trial, the students at Dental School of Isfahan University of Medical Sciences were divided into two control and intervention groups (via a random number table), with 37 persons in each group. The classroom was held traditionally for both groups in 3 sessions and the podcast file was provided to the intervention group at the end of the session. Then, a test was taken from both groups at the second and third sessions. The students’ answers were evaluated and each score was determined out of 5. The scores of this test were compared in the intervention and control groups. Finally, a questionnaire was provided to students to evaluate their satisfaction. The test scores were analyzed by independent T-test.
Results: In this study, with 74 participants, the average age was 22.47±0.85, and 43% of the participants were male. The scores of the two tests taken out of five were 4.86±0.10 in the intervention group and 4.04±0.94 in the control group, and a significant statistical difference was observed in favor of the intervention group (P=0.02). The average satisfaction of students regarding this educational method was 29.4 out of 50. After taking into account the confounding effect of age, the investigated intervention did not affect the average score of the students' questionnaire (P=0.031).
Conclusion: According to the findings of the present study, podcasts could be effective in students' learning and students had a positive attitude towards this method. The results of this study can be used as a feedback to the educational committees of the Iranian Ministry of Health and Medical Education.