مجله دانشکده دندان پزشکی اصفهان
سال دهم شماره 1 (پیاپی 42، فروردین 1393)

The most common cause of dental caries is the Streptococcus mutans. Control of dental caries with the use of mouthwashes has been introduced for many years. The aim of this research was to make a comparison between the antibacterial effects of chlorhexidine and Nigella sativa extract as a natural mouthwash. In this in vitro study، salivary samples of 20 subjects were transferred onto a solid culture. Then 10 subjects، as group 1، used chlorhexidine and the remaining 10، as group 2، used apple extract. The salivary samples of both groups were again transferred onto the solid culture. The number of grown colonies in each group before and after the use of mouthwashes were counted and compared. Data were analyzed with t-test using SPSS 17 (α=0. 05). The results did not show a significant difference between the colony counts before the use of mouthwashes; but the average number of colonies after interference in group 1، (p value < 0. 001) and in group 2 (p value < 0. 002) significantly decreased. The decrease in colony counts of group 1 was significantly more than that of group 2 (p value < 0. 001). The bacterial reduction percentages after interference with chlorhexidine and Nigella sativa extract were 92. 8% and 54. 5%، respectively. Nigella sativa extract can be used as an antibacterial substance for the oral cavity; however، chlorhexidine is still considered a standard and more effective mouthwash.

Biocompatibility is one of the most important properties of endodontic sealers. The aim of the current study was to investigate the cytotoxicity of four endodontic sealers (AH26، MTA Fillapex، tgsealer and ADSEAL) on human gingival fibroblasts in vitro. In this in vitro experimental study، four endodontic sealers were evaluated in fresh and set states. The fresh and set specimens were separately extracted in RPMI-1640 (Sigma-Aldrich، USA). The extracts were placed for 1، 3 and 7 days in close contact with C165 human gingival fibroblast in cell culture. Then the samples cytotoxicity was assessed by MTT assay (3-(4،5-dimethylthiazol-2-Yl) -2،5-diphenyltetrazolium bromide) and spectrophotometric analysis. Data were analyzed with multivariate analysis of variance using SPSS 11. 5 (α=0. 05). The results showed that all the sealers were cytotoxic. According to statistical analysis a significant difference was seen between fresh and set specimens in AH26 (p value = 0. 028) but there were no significant differences in ADSEAL (p value = 0. 910)، MTA Fillapex (p value = 0. 952) and tgsealer (p value = 0. 566) between the two sealer states. In addition، based on means of all the data of each sealer MTA Fillapex (0. 78) had the least cytotoxicity and ADSEAL (0. 60) had the highest cytotoxicity. It can be concluded under the limitations of the present study that among the sealers evaluated in the present study MTA Fillapex and ADSEAL had the highest and lowest cytotoxicity، respectively.

The current orthodontic treatments have shifted toward the principles of dentofacial orthopedics and nonextraction treatment modalities. One of these orthopedic procedures is the skeletal palatal expansion of the maxilla. The aim of this investigation was to study the skeletal and dental modifications in all the three dimensions by skeletal maxillary expansion with hyrax appliance.

In this preliminary study، 8 patients (4 males، 4 females)، aged 8–13 years (mean age 9. 7 years)، were selected. The appliance used in this study was the Hyrax screw bonded on the first molars of the maxilla. The active phase of the treatment and the retention period lasted for 2 and 4 months، respectively. Lateral and posteroanterior (PA) cephalograms were taken and traced. Measurements were carried out on pre- and post-operative study casts. Wilcoxon test was used to compare means of each variable with SPSS 10. 5 (α=0. 05).

The transverse dimension of the maxilla increased both dentally and skeletally after treatment. The mean increase in skeletal transverse dimension at maxillary molar area (4. 8 mm) was greater than that at canine area (3 mm)، which was statistically significant. In the mandibles the increase in the transverse dimension at molar area (4. 8 mm) was less than that of the maxilla. Arch perimeter of the maxilla increased significantly (3 mm) (p value = 0. 012). In the vertical dimension، the posterior maxilla exhibited more downward movement compared to the anterior maxilla. The increase in facial height was not statistically significant (p value = 0. 396). There were no significant changes in the positions of maxillary and mandibular incisors (p values = 0. 343 and 0. 397).

The Hyrax appliance، with two-point contact، was more successful in posterior palatal expansion than the anterior area without any significant effect on the facial height and the positions of anterior teeth.

Various techniques are used to diagnose periodontal diseases. Radiography is a useful tool in the diagnosis of periodontal disease، determination of the prognosis and treatment. The aim of this study was to compare the accuracy of determining the distance between the alveolar crest and CEJ in digital radiography with Scanora and Dental Eye software programs. In this in vitro study 63 sites in a dry human mandible underwent digital periapical radiography. The distance from the alveolar crest to the CEJ was calculated using Dental Eye and Scanora software programs and compared with the standard mode (measured on the skull). Statistical analysis was performed with ANOVA and paired t-test using SPSS 20 at α=0. 05. There were significant differences in the distances between CEJ and the alveolar crest at the mesial surfaces as measured by the three techniques of standard mode، Dental Eye and Scanora (p value ≤ 0. 03); however، there were no significant differences between the results on distal surfaces (p value = 0. 248). Under the limitations of the present study، the measurements made to determine the distance from the CEJ to the alveolar crest with Dental Eye and Scanora، relative to each other، and relative to the standard mode، were accurate only on distal surfaces of teeth.

The most important function of speech is communication and any disorder in speech undoubtedly affects communication with other people. Speech disorders have a significant effect on social development of human beings. This study was undertaken to evaluate the relative incidence of speech disorders in sagittal dento-alveolar disorders. In this descriptive analytical study 95 patients referring to the Orthodontics Department of Khorasgan Dental School in spring 2008، who met the inclusion criteria (subjects with one of the Angle’s 3 classes of malocclusion based on preliminary evaluations، no history of orthodontic treatment and with no other problems such as mental retardation or cleft palate) were randomly selected and underwent dentofacial examinations. A speech therapist evaluated the subjects’ speech disorders via phonetic test and colloquial speech. Data were analyzed with chi-squared test using SPSS 16 (α=0. 05). Chi-squared test did not reveal any significant relationship between speech disorders and Angle’s malocclusion (p value = 0. 07). The group with dentofacial disorder and the group without it were matched in relation to sex (p value = 0. 092) and age (p value = 0. 543). In addition، of all the consonants the most common disorder was related to abrasive consonants and the speech disorders were not evenly distributed among all the consonants (p value < 0. 001). The results showed no significant relationship between speech disorders Angle’s malocclusion. The most frequent disorder was related to abrasive consonants.

Microleakage is one of the most important reasons for the failure of composite resin restorations. Use of liners releases the stresses of polymerization shrinkage. The aim of this study was to evaluate microleakage of posterior nanocomposite restorations with three types of liners. In this in vitro study forty-eight sound human premolars were randomly assigned to four groups. Classic class II cavities were prepared with gingival margins 1 mm coronal to the CEJ. Cavities were lined in group I with Filtek Z350 flowabl composite resin، in group II with F2 dual-cured composite resin and in group III with Fiji II LC resin-modified glass-ionomer; no liner was placed in cavities in group IV. All the teeth were restored with a posterior nanocomposite (Filtek Z350) to a thickness of 2 mm using horizontal technique except the teeth in group IV in which first a 1-mm layer was placed، followed by a 2-mm second layer; each layer was light-cured for 40 seconds. The teeth were immersed in 2% fuchsin dye، sectioned mesiodistally and observed under a stereomicroscope for dye penetration. Data was analyzed with non-parametric Kruskal-Wallis and Mann-Whitney tests (α=0. 05). Statistically significant differences were observed between the groups (p value = 0. 048). Group I (lined with flowable composite) exhibited maximum leakage; group III (lined with resin-modified glass-ionomer) exhibited the minimum microleakage، which was significantly different only from Group I (p value = 0. 006). The results of this study indicated that none of the liners under study could thoroughly eliminate microleakage of posterior nanocomposites. No differences were observed in microleakage between the groups with liner application.

Trauma is considered a major problem in public health. Follow-up is of utmost importance in achieving desirable treatment results. The aim of the current study was to evaluate traumatic dental injuries and their follow-up in patients attending Isfahan Dental School. In this retrospective descriptive study the records of all the patients attending the School’s Endodontic and Pediatric Department clinics with a chief complaint of trauma were assessed. Data including the treatments، follow-ups after the treatment، reasons for a halted follow-up، level of chart completeness، demographic data، tooth numbers، types of trauma، reasons for trauma and the place it occurred، and the time interval between the accident and dental visit were evaluated. Data were analyzed by descriptive statistics using SPSS 18 at a significance level of 95%. Of 207 traumatized teeth in 127 patients، the most frequent tooth involved was the permanent maxillary central incisor (69. 6%). The most frequent type of injury seen was crown fracture (33. 8%). Falls and collapses (44. 8%) were the most frequent underlying reasons for injuries. The mean number of follow-up visits was 2. 38 times. The most frequent time interval between the accident and dental visit was one week (21. 8%)، followed by 24 hours (20. 3%). Only 21. 2% of the files were complete and comprehensive. According to the present study، the most frequent tooth with trauma، type of injury and underlying reason for the injury were permanent maxillary central incisors، crown fractures، and falls.

Epidemiological considerations indicate the importance of prevention، diagnosis and treatment planning. The aim of this study was to assess the prevalence of different types of traumatic dental injuries (TDI) and their etiology in patients referred to Shiraz Dental School in order to find a reliable preventive pattern for TDI. This descriptive‒analytical study examined the files of 314 patients، who referred to Shiraz Dental School (2008‒2012)، with 554 traumatized teeth. The variables investigated included age، sex، type of the involved tooth، type of TDI، place of occurrence، reason for injury and intervals between injuries and the time of referral to Shiraz Dental School. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis and comparison of TDIs based on demographic data using SPSS 16 (α=0. 05). Of all the patients، men and women accounted for 65. 9% and 34. 1%، respectively. The mean age was 17. 37 years. In average، the number of traumatized teeth in all the files was more than 1 tooth. The most frequent traumatized teeth were permanent maxillary first incisors (64. 4%). Falls were the most frequently cited etiological factors in TDI (33. 7%)، followed by car accidents (25. 2%) and complicated crown fracture was the most common TDI (20. 2%); 64. 9% of patients had referred to Shiraz Dental School less than one month after trauma. No significant differences were observed between males and females in the frequency and mean age of the trauma types (p value > 0. 005). Based on the results of the present study، falls (33. 8%) and car accidents (25. 2%) were the most frequent etiologic factors for TDI، respectively، with the streets as the most frequent place of accidents (44. 9%).

Dentists are in a unique position to recognize and report child abuse (CA)، as head، face and neck injuries occur in more than half of cases of CA. The aim of the present study was to assess the knowledge of، attitudes toward and experience about CA and neglect among dentists.

A cross-sectional study by means of a multi-stage sampling was carried out among dentists working in Isfahan University of Medical Sciences، private offices and dental clinics in Isfahan، Iran. Data were gathered through a self-administered questionnaire from 134 general dental practitioners and 40 dental specialists. Spearman، Pearson، one-way ANOVA and Friedman analyses were applied at a confidence interval of 95%.

Dentists showed insufficient knowledge on different types and signs of CA. Dentists had positive attitudes toward the diagnosis of CA and demonstrated great interest in reporting suspected CA cases to the authorities (the mean attitude score was 15. 1 of 20). Female dentists showed more positive attitudes than their male colleagues (p value = 0. 03). Of dentists، 11. 5% reported to have had suspicions of CA and neglect and only one of them (5%) had reported some of these cases to social services. The most important barriers towards reporting suspected cases to social services were uncertainty of the occurrence of CA and lack of adequate knowledge about CA.

Under the limitations of the present study، dentists had low knowledge about، positive attitudes toward and insufficient knowledge about child abuse. It is suggested that special courses on child abuse be incorporated into dental curricula and into continuing education and scientific conference programs for dentists.

Today، new developments in the field of computer hardware and software have led to the production of advanced equipment and devices in industry، including the dental field. One of these devices is computer-aided design (CAD) and computer-aided manufacture (CAM) system. CAD/CAM systems are able to collect data and design and manufacture a wide range of dental restorations such as inlays، onlays، veneers، crowns، fixed partial dentures، orthodontic appliances and dental implant abutments. The aim of this article is to review the history of CAD/CAM، types of available CAD/CAM systems، how they function and application concepts in digital dentistry. Article description: This article was collected by scientific search in electronic resources، books، Pubmed and ISI Web of Science websites، in articles published in English until 2013، and with the following key words: history، advantages and disadvantages، an overview of the components and the performance of CAD/CAM systems in dentistry. In recent years، digital technology is advancing rapidly in dentistry and now it can be applied to almost any restorative situation، including full-mouth rehabilitation. Computer technology has made fabrication of restorations easier، faster، cheaper and more predictable than before. While there are many benefits for dental digital systems، it is necessary for the dental team to master their function in order to maximize their advantages for creating well-fitting restorations.