مجله دانشکده دندان پزشکی اصفهان
سال شانزدهم شماره 3 (پیاپی 72، پاییز 1399)

 The cause and incidence of the maxillofacial fractures changes according to the mechanism of the injury and demographic factors. Detecting the possible relationship between the causes of the accident and the most common bone areas that usually affected by that specific accident, can be helpful in faster and easier diagnosis of the type of possible injury in traumatic patient. So the aim of this study was to evaluate the relationship between the distribution of midface and mandibular fracture areas and the causes of the accident and also investigation of the epidemiological factors.

 This is a retrospective descriptive study and datas were analyzed with Chi-square and Fisher exact analysis tests with SPSS 16 (95% CI).

 This study was done on 216 patients with a total of 249 midface and mandibular fractures. The ratio of males to females was 7.1. The age range was 5 to 82 years (mean 29 years). Most fractures were related to midface (50.6%) and in age range 20-30 years old. distribiution of Fractures in age groups (p value < 0.027), distribiution of accident causes in two generic groups(p value < 0.001), distribiution of accident causes in separation of midface from mandibular fractures in two generic groups(p value < 0.0001, p value < 0.002, p value < 0.001) and distribiution of treatment process in separation of midface from mandibular fractures (p value < 0.0001) were statistically significant. Distribution of accident causes in age groups (p value < 0.0001) and in separation of midface from mandibular fractures, was only significant in midface. The most frequent cause of fractures in males was motor cycle accident and in females was car accidents .Nasal is the most common fracture site of the midface (46.25%) and body (61.23%), parasymphysis (18.52%) and angle(16.2%) are the most common fracture sites of mandible. Angle and zmc were most fractured in fight, parasymphysis was most fractured in falling and other causes are mostly lead to a broken nose.

 Having the Knowledge about the sites that are most commonly fractured in every accident, can helps the clinician in recognizing the sites that should pay more attention to them.

One of the most common problems after implant treatment is peri-implant disease. Recognizing the prevalence of peri-implant disease has a significant role in reducing unwanted complications after implant placement.The purpose of this study was to determine the prevalence of peri-implant disease in patient referring to periodontics department of Yazd Dental School.

In this cross-sectional study, for patients who have been placed the implant inthe periodontics department of dental school in the period of six years, clinical examination and patient records done. Finally, the data were analyzed by SPSS 18 software and Chi-square statistical test.

In this study there was a significant relationship between healthy group and peri-implantitis in the terms of gender (p value= 0.047).but there is no significant relationship between age groups (p value = 0.385). There is a significant relationship between systemic disease (p value = 0.071), probing depth (p value = 0.0001), presence of keratinized mucosa (p value = 0.001) and smoking (p value = 0.036) with peri-implantitis. This relationship is not significant in the plaque index variable (p value = 0.229). There is significant relationship between implant type and peri-implantitis(p value = 0.030), but there is no significant correlation for implant location (0.872), prosthesis type (0.678), implant method (0.367).There is direct relationship between the date of implant placement (p value = 0.01, rs = 0.229) and implant diameter (p value = 0.927, rs = 0.08) with peri-implantitis and inverse relationship between implant length (p value = 0.296, rs = 0.046) and peri-implantitis, which is statistically significant only in date of implant placement variable.

Based on our data, prevalence of peri-implantitis in patients referred to periodontics department was 84.9%. Statistically significant relationship was shown between gender, systemic disease, probing depth, keratinized mucosa, smoking, implant type, bridge and date of implant placement and peri-implantitis.

 The disinfecting effect of root filling materials used in pulpectomy is imperative for the elimination of residual pathogenic microorganisms from the root canal system. This study aimed to assess the antimicrobial effect of ZOE mixed with different concentrations of nanosilver on bacteria commonly isolated from the primary teeth with necrotic pulp.

 This in vitro study evaluated the antimicrobial effect of ZOE mixed with 0%, 0.5%, 1%, 2%, and 5% concentrations of nanosilver on Enterococcus faecalis (E. faecalis), Streptococcus mutans (S. mutans), and Escherichia coli (E. coli) using the direct contact test. Nanosilver was mixed at different concentrations with ZOE and applied to microplates. Suspensions of standard strains of E. faecalis, S. mutans, and E. coli were prepared and exposed to the mixtures. Brain heart infusion broth was also added. Samples of the culture medium were taken from the wells after1 hour and 1, 2, and 7 days and added to a saline solution to obtain the respective dilutions and cultured on brain heart infusion agar. Finally, the number of colonies was counted. Data were analyzed with two-way and three-way ANOVA using SPSS 22 (α = 0.05).

 The mean colony counts significantly decreased following exposure to different concentrations of nanosilver mixed with ZOE, with significant differences between the groups (p value < 0.05). The mean colony counts significantly decreased over time at all the concentrations (p value < 0.05).

 The results showed that the incorporation of nanosilver by up to 5% to ZOE enhanced its antibacterial activity against E. faecalis, S. mutans, and E. coli. Moreover, the mixtures retained their antibacterial property over time.

With increasing advances in medical science and increasing longevity of people, the number of the elderly and patients with cardiovascular diseases, referring to dental offices, has increased significantly. This study aimed to evaluate the knowledge of general dental practitioners about dental considerations in cardiac patients in Shiraz, Iran.

In a descriptive and analytical study, 217 general dentists, selected randomly, were questioned. The participants completed a questionnaire consisting of eleven questions. Data was then collected, coded, and analyzed with SPSS 18 using t-test and one-way ANOVA (α = 0.05).

Of all the 217 participants, 52% were male, and 48% were female. The average score was 6.29. The average knowledge score was higher in participants having graduated from domestic universities compared with those having studied abroad. The rate of knowledge decreased with aging and an increase in working years. The rates of knowledge were high in 25%, medium in 55%, and low in 20%.

This study showed that the knowledge of general dental practitioners in Shiraz was not sufficient about dental considerations in cardiac patients. Therefore, continuing education programs are necessary to enhance their knowledge.

 Investigations into continuing education programs are necessary to identify the needs and priorities, motivate the participants, and improve their benefits. This study was performed to assess dentists’ viewpoints about the aims, the content, and the relevant factors in the prosthodontics congress.

 This descriptive cross-sectional study was conducted on 270 dentists participating in the 52nd Iranian Dental Association Congress (2016). The questionnaire consisted of demographic data and 12 statements, with six statements supporting participation in the Congress and six against it. Likert scale was used to score the questionnaire, and its validity was evaluated with t-test. The participants’ attitudes were determined, and the relevant factors were assessed with regression analysis.

 4% of the dentists had a highly positive attitude towards participating in the congress, 73% had a negative attitude, 22.6% had a negative attitude, and 0.4% had a highly negative attitude. The most important reason for a positive attitude was discussions and debates in the Congress (93%), followed by making more money (71%), and the least motivation (6.6%) was familiarity with new methods and tools.

 Although the participants’ positive attitudes were at a favorable level, their motivation was not favorable, causing some concern. Most dentists participated in continuing education programs with non-scientific motives. Measures are recommended for improving motivations for participating in congresses.

 One of the common concerns among dental students is stress during practical exams. Based on the available studies, stress might increase salivary cortisol levels. On the other hand, light music has a significant role in decreasing stress. This study aimed to evaluate the effect of listening to light music on salivary cortisol levels in dental students.

 In this cross-over study, 20 students of the Islamic Azad University in Tehran were selected using an objective-biased method and divided into two groups of A and B. The subjects were given a practical tooth preparation test. Light music was first played for group A subjects and then for group B subjects. On both exam days, 1 mL of unstimulated salivary samples were collected in a special container from all subjects before and after the exam and 5 minutes after they washed their mouth with water. The samples were sent to the laboratory for measuring salivary cortisol levels. Data were analyzed with the Kolmogorov–Smirnov test and paired t-test using SPSS 22.

 In the group which listened to light music while sitting for the exam in the first week, there was a significant difference in the salivary cortisol levels before and after the first test at around 1.07 ± 1.19 (p value = 0.019), with higher levels of cortisol before the exam. In the second-week group, there was a significant difference in salivary cortisol levels after the first exam at around 0.57 ± 0.29 (p value = 0.001), with higher cortisol levels before the exam.

 Listening to light music decreased salivary cortisol levels, indicating lower stress levels.

Due to the increasing population of the elderly and the ever-increasing need for evaluating dental implants preoperatively, it is necessary to find a method with the best diagnostic accuracy. Therefore, this study aimed to compare the accuracy of panoramic views of CBCT radiography using Ondemand software in determining the indices used in the implant treatment planning of the edentulous posterior maxilla.

This cross-sectional, descriptive/analytical study was performed on CBCT radiographs of 43 patients (113 teeth) requiring implants in the archives of a private radiology center. Two panoramic and cross-sectional views were compared in each CBCT radiograph to compare different variables, including ridge height, pathologic entities, septa, and sinus lift requirement. McNemar test and Paired t-test were used for data analysis. The significance level was considered at p value = 0.05.

The results showed no significant differences in the means and standard deviations of the height of the residual ridge between panoramic and cross-sectional CBCT views in any of the teeth studied (p value = 0.113). Maxillary sinus septa, the need for a sinus lift procedure, and probable pathologic entities were not significantly different between panoramic and cross-sectional CBCT views (p value = 0.99).

Under the limitations of the present study, it can be concluded that both panoramic and cross-sectional views are highly accurate in assessing the ridge height, septa, pathologic entities, and need for a sinus lift procedure.

 Given the dimensional changes in implant impressions and its complications, and the introduction of intraoral scanners that are likely to result in less dimensional changes, this study aimed to compare the dimensional changes of digital and conventional impression techniques in dental implants.

 The experimental study was conducted on 20 samples. First, a Ceramill laboratory scanner (Amann Girbach, Austria) was used to scan a stainless steel model. In the conventional impression group, an impression was taken with the open tray technique, and after pouring the cast, a digital model was prepared using a laboratory scanner. In the digital impression group, an intraoral scanner (Dentsplay Sirona, USA) was used to scan the stainless steel model 10 times. Each digital file obtained from groups 1 and 2 was superimposed on the Studio software environment (Geomagic® Studio 3D Systems, Rock Hill, SC, USA), and their dimensional changes were calculated. One-way ANOVA was used to evaluate dimensional changes of the two groups. Data were analyzed with SPSS 25.

 The results showed that the dimensional changes in conventional and digital impression groups were 0.178 ± 0.057 and 0.110 ± 0.43, respectively, with a significant difference.

 The impression accuracy for implant prostheses at different angles, using an intraoral scanner, was higher than the conventional impression technique using an impression material.

 It is essential to study the biocompatibility of composite resins, including the leached components and their potential impact on human health. This study investigated the elution of organic components of a conventional composite resin and Ormocer in different environments.

 In this experimental study, a Teflon mold was used to prepare 32 samples of two types of composite resin (All-purpose methacrylate-based microhybrid composite resin and Ormocer [Admira Fusion]) with a diameter of 6 mm and a height of 2 mm. The samples were immersed in distilled water and methanol. After 24 hours and 7 days, the amounts of TEGDMA, UDMA, and CQ in Ormocer released were checked by a gas chromatography device; the results were analyzed with one-way ANOVA and Tukey tests using SPSS 23 (α < 0.05).

 The elution of TEGDMA, UDMA, and CQ in Ormocer were significantly lower than microhybrid composite resins (p value < 0.009), and the significant difference persisted over one week for both materials (p value < 0.001).

 The Ormocer composite showed the lowest elution of TEGDMA, UDMA, and CQ components compared to the microhybrid composite resin. The elution of Ormocer composite resin in water was lower than that in methanol; also, the elution of CQ of Ormocer composite resin in methanol was higher than other components.

 Fracture of the denture base and its repair are one of the main concerns of patients with a complete denture. This is often due to patients’ carelessness in maintaining dentures, or a low strength and resistance of the acrylic resin. This study aimed to compare the fracture resistance of heat-cured, self-cured, and injectable acrylic resins using a three-point flexural test.

 In this experimental study, 30 blocks of acrylic resin (Ivoclar VivaDent-Liechtenstein), measuring 2.5×25×50were prepared with three methods of heat-cured¸ self-cured, and injection. The samples were incubated for 24 hours to simulate the oral conditions. The samples were then subjected to three-point flexural testing in a universal testing machine. The force required for the failure of the samples was measured, and the results were compared and analyzed using Kruskal-Wallis and Wilcoxon tests with SPSS 22 (α = 0.05).

 Among the three samples, the fracture resistance of the self-cured acrylic resin was the lowest, and the fracture resistance of the injected acrylic resin was the highest. The differences in fracture resistance between the acrylic resins were significant (p value < 0.001).

 Since the injected acrylic resin exhibited the highest fracture resistance, it is more appropriate for the fabrication of fracture-resistant dentures.

 CBCT imaging systems are widely used in different dental treatment fields in recent years due to their advantages, such as obtaining 3D images, ease of image acquisition, and reconstruction of data. This study assessed the knowledge and attitudes of dentists in Tehran about the use and indications of the CBCT technique in 2017-2018.

 In a descriptive cross-sectional study, 199 dentists in Tehran were selected. A questionnaire was designed using standard methods with 24 items. The knowledge scores of the dentists were calculated by assigning 1 score to each correct answer and 0 for each incorrect answer. A linear regression test determined the effects of different parameters on the knowledge scores. SPSS was used for statistical analyses. Spearman’s correlation coefficient was used to analyze the relationship between the knowledge scores and the answers provided for some questions.

 The mean knowledge score of the dentists about CBCT prescription indications was 7.77, with a standard deviation of 2.02. The knowledge score range was 3-15. The mean scores of knowledge were similar regarding different parameters. The years in the dental occupation among dentists, age, prescription of CBCT for the patients, or intention to receive education on CBCT software did not affect the prediction of knowledge scores of the dentists (p value < 0.19).

 Since dentists in Tehran exhibited moderate knowledge regarding the indications of CBCT, efforts should be made to improve their knowledge level due to their responsibility in oral health and the benefits of CBCT images to increase the quality of dental treatments.

 It is of utmost importance to achieve a non-invasive method to diagnose secondary caries next to amalgam restorations. In many cases, clinical examination alone does not allow an accurate diagnosis of recurrent and proximal caries; therefore, appropriate radiographs and Diagnodent are required. The use of Diagnodent (laser fluorescence) and intraoral digital x-ray radiography (PSP) is increasing instead of visual inspection and tactile examination. Given the discrepancies in the results of studies about Diagnodent and digital x-ray radiography (PSP) for the detection of secondary caries, this study aimed to compare the diagnostic power of Diagnodet and intraoral digital radiography to detect secondary caries in class II  amalgam restorations.

 In this diagnostic study, 40 healthy human premolar teeth were used. First, 40 class II cavities were prepared and restored with amalgam. In the first stage, the teeth underwent radiography with an intraoral PSP system and saved. The teeth were then immersed in 0.1 mol lactic acid (pH = 4) to simulate recurrent caries for three weeks. Diagnodent was used in the clinical diagnosis to detect recurrent caries. In the final stage, teeth with recurrent caries underwent digital radiography. Finally, two oral and maxillofacial radiologists evaluated all the 80 radiographs. T-test was used to analyze the false-positive (FP) and false-negative (FN) results of the two techniques with SPSS 16 (α = 0.05).

 The study was carried out on 40 teeth using Diagnodent and intraoral PSP radiography. Incorrect diagnoses (FP and FN) were recorded in 28.5% and 21.2% of the cases with digital radiography and Diagnodent techniques, respectively (p value = 0.3).

 Diagnodent and intraoral digital radiography exhibited similar diagnostic power in the detection of secondary caries around class II amalgam restorations.

 Soft tissue grafts are used around dental implants for different purposes. Autogenous soft tissue graft techniques have yielded favorable results. However, these techniques increase the duration of surgery and postoperative complications. Allogeneic and xenogeneic tissues have advantages over autogenous grafts. Numerous studies have reported successful treatment outcomes with acellular dermal matrix (ADM) as an alternative to autogenous soft tissue for treating mucogingival defects around dental implants. This study aimed to review various soft tissue techniques around dental implants.

 In this systematic review, a search was run in four databases, including PubMed, Scopus, Web of Science, and Cochrane until January 2020 with these key words: soft tissue augmentation, dental implants, keratinized gingiva and acellular dermal matrix.

 Autogenous connective tissue graft is the gold standard technique for increasing the thickness of soft tissue around dental implants. The use of allogeneic materials as an alternative to these tissues is associated with some advantages.

 ADM is a suitable alternative for autogenous connective tissue grafts to increase the thickness and width of keratinized tissue around dental implants.

 Apexification with calcium hydroxide is the traditional method to create an apical seal in open-apex teeth. Recently, single-visit apexification with suitable materials has gained popularity. A material suggested for this aim should have low solubility, low toxicity, and biocompatibility, and induce a calcified barrier and regenerate bone and PDL. Cold ceramic, introduced as a root-end filling material, has exhibited favorable properties for apexification in previous studies.

This case report describes successful apexification of a maxillary right central incisor in a 10-year-old girl with cold ceramic. One- and two-year follow-ups showed resolution of the lesion, absence of any clinical signs, new PDL formation, and bone regeneration.

 According to the results, cold ceramic can be considered an effective material for apexification.