Journal of Islamic Dental Association of IRAN
Volume:31 Issue: 1, Winter 2019

Improving the bond strength at the resin-dentin interface is an important challenge in adhesive dentistry. This study examined the effect of low-power, non-thermal atmospheric pressure plasma (NT-APP) treatments on the adhesion of a self-adhesive resin composite to dentin. In this experimental in-vitro study, buccal enamel of extracted bovine incisors was removed using a high-speed diamond bur. The specimens were randomly divided into two groups according to the plasma treatment and thermocy-cling. The non-thermal atmospheric argon plasma brush was used in this study. One subgroup was subjected to the microshear bond strength (µSBS) test after 24 hours, whereas the other subgroup was subjected to artificial aging with thermocycling for 5000 cycles before being tested. Each specimen was attached to a testing jig and loaded at a crosshead speed of 1.0 mm/minute in a universal testing machine until failure occurred. Data were analyzed using two-factor repeated measures analysis of variance (ANOVA). The results of μSBS testing showed that with plasma treatment, the average μSBS increased to 34.20±12.12 MPa compared to 19.47±7.4 MPa in the controls (P=0.002). After 5000 cycles of thermocycling, the adhesive-dentin bonding strengths of the plasma-treated specimens slightly decreased from 34.20±12.12 MPa to 33.64±5.6 MPa (P=0.886), while the strengths of the untreated specimens reduced from 19.47±7.4 MPa to 19.10±5.1 MPa (P=0.461). Plasma treatment improved the µSBS compared to the control group. After thermocycling, the µSBS did not decrease in the plasma and control (non-plasma) groups. Plasma treatment using NT-APP improves the adhesion of self-adhesive flowable resin composites to dentin.

Because of complexity in root canals, irrigating solutions are needed in addition to mechanical instrumentation for thorough cleansing of the root canal system. This in-vitro study was designed to determine the inhibitory effect of arginine, protamine, and aqueous extracts of green tea and aloe vera against Enterococcus faecalis (E. faecalis), which causes endodontic failure. In this experimental study, aqueous extracts of green tea and aloe vera and protamine at a concentration of 400 mg/ml and arginine at a concentra-tion of 160 mg/ml were used. E. faecalis was cultured on Mueller-Hinton broth, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the test materials against these microorganisms were determined using serial dilutions and according to the microdilution test. The positive control was 2.5% sodium hypochlorite (NaOCl). Aqueous extract of aloe vera has high antibacterial activity against E. faecalis (MIC=12.5 mg/ml and MBC=100 mg/ml), and protamine had the least effect (MIC=400 mg/ml and MBC>400 mg/ml) compared to other test materials. NaOCl, with MIC and MBC of 0.25 mg/ml against E. faecalis, showed higher antibacterial activity compared to other test materials. Among the tested materials, except for NaOCl as a positive control, aqueous extract of aloe vera showed better antibacterial properties against E. faecalis.

Intraosseous implants can be placed using three different techniques: immediate, early, and delayed. The aim of this study was to compare the changes in the marginal bone level around implants after immediate and delayed im-plant placement. In the present prospective cohort study, 26 implants were placed in 26 patients divided into two groups. In group 1, 13 implants were placed immediately, while in group 2, 13 implants were placed with a delay of more than 4 months after tooth extraction. The marginal bone level was measured on periapical radiographs taken using the parallel technique at implant placement time and 6 and 12 months after implantation. The measurements were made using a digital caliper with an accuracy of 0.01 mm, and the data were analyzed using repeated-measures analysis of variance (ANOVA) and Mauchly's sphericity test. The statistical significance was set at P<0.05. The mean distances between the crestal bone and the implant shoulder in group 1 were 1.12 mm, 1.48 mm, and 1.77 mm at implant placement time and 6 and 12 months postoperatively, respectively. In group 2, these distances were 1.26 mm, 1.46 mm, and 1.71 mm, respectively. There were no significant differences in marginal bone resorption between the two groups (P>0.05). There was no significant difference in crestal bone loss around implants placed with immediate and delayed techniques.

The proportion of smile is a useful tool for creating geometric smiles which are a critical aspect in esthetic dentistry. The aim of this study was to determine the effect of lip line position on acceptable Recurring Esthetic Dental (RED) proportion among lay people. A photograph of pose smile of a young female was taken. The position of the lip was changed by Adobe Photoshop CS6 software within three positions (low, medium, and high). Then, we created three RED proportions (54%, 62%, and 70%) for each lip line position. The photographs were ranked from most to least attractive (one to nine) by 40 lay people (20 females and 20 males) with a mean age of 19.4 years. Data were collected and analyzed using Friedman test. Pairwise comparisons were made using Bonferroni correction. The impact of gender on the ratings was evaluated using repeated measures analysis of variance (ANOVA). In the medium lip line group, all three proportions had approximately the same preference rates. The 54% proportion was the least attractive one in the high lip line group (mean=6.819), and the 70% proportion was the least attractive one in the low lip line group (mean=6.881). The acceptable RED proportion cannot be evaluated without consideration of other factors such as lip line position. Esthetics is the result of a harmonious balance between different elements.

Stress has been associated with recurrent aphthous stomatitis (RAS). The common treatment of RAS is a topical steroid. This study aimed to investigate the difference of salivary cortisol between RAS patients treated with a topi-cal steroid and those without treatment. Thirty-two female patients with RAS participated in this case-control study and were randomly divided into two groups: the case group (n=16) treated with a topical steroid and the control group (n=16) without any treatment. The inclusion criteria comprised of non-pregnant women with RAS. The exclusion criteria consisted of having other diseases, taking medications, and smoking. All subjects were examined for pre- and post-treatment salivary cortisol at the onset of the ulcers in the case group and when the ulcers were healed in the control group. Data on the characteristics of the subjects were collected and presented descriptively, and the difference in salivary cortisol was analyzed using Mann-Whitney-U test and independ-ent t-test with a 95% confidence interval (CI) in SPSS 17.00 software. The mean salivary cortisol in the pre-treatment group (10.51±5.15 ng/ml) was higher than that in the post-treatment group (9.30±3.77 ng/ml). The mean salivary cortisol at the onset of RAS (9.55±4.03 ng/ml) was lower than when RAS was healed (13.07±3.82 ng/ml) in the control group. There was a significant difference in the mean of pre- and post-treatment salivary cortisol levels between the case and the control groups (P<0.05). Topical steroids may not only reduce inflammation of oral ulcers but also may reduce salivary cortisol in RAS.

Space maintenance is an important process in the mixed dentition as a preventive measure for multiple malocclusion problems related to the loss of arch length. The awareness of parents and the satisfaction of children are two critical factors determining the efficacy of space maintainers. The aim of this study was to as-sess the level of parents’ awareness of space maintainers in their children’s oral cavity and the level of their children’s satisfaction with these appliances. In the present descriptive-analytical study, a questionnaire was completed by 200 elementary school children, aged 6-12 years old, and by their parents, which was consisted of four main categories: 1) demographic data, 2) parents’ occupation and educational level, 3) parents’ awareness of the uses and maintenance of space maintainers, 4) children’s satisfaction with space maintainers. Data collected from these questionnaires were analyzed in Stata 14 software. The significance level was set at P<0.05. The mean awareness score of the parents was 57%, with no significant relationship with their educational level or occupation (P=0.819). The mean score of the children's satisfaction was 74%; however, the satisfaction significantly decreased with age (P=0.05). There was a significant correlation between children's satisfaction and the type of space maintainer (P=0.0001). The level of awareness of parents about the usage, maintenance, and advantages of space maintainers was average, whereas the satisfaction of children with the usage, maintenance, and comfort of space maintainers was high.

Oral lichen planus (OLP) is a chronic, inflammatory, T-cell-mediated autoimmune oral mucosal disease. Oral lichenoid lesions develop as a type IV hypersensitivity reaction. Both of these entities are potential precancerous conditions; this adds to their clinical significance. The purpose of this literature review was to detect the similarities and the differences of these lesions to enhance the information of colleagues in managing these groups of patients. For this review, we searched Cochrane, Medline, and Embase databases from January 1990 to the end of October 2018. A total of 96 published pa-pers, including review papers, case reports, cohort studies, case-control studies, and meta-analysis studies, were included and analyzed. OLP and oral lichenoid reactions are two distinct diseases. They can be clinically similar but they have different etiologic factors. A histopathological study is necessary to differentiate them. The definitive diagnosis of these conditions is extremely important given their potentially premalignant nature. A timely diagnosis probably results in proper management. Based on the present research, the final differentiation between OLP and oral Lichenoid reactions relies on both clinical and histopathological manifestations according to the modified World Health Organization (WHO) criteria.

Dentigerous cysts (DCs) are the most common developmental cysts of the jaws, mostly associated with impacted third molars and canines. Multiple or bilateral DCs are rare and typically occur in association with some syndromes including cleidocranial dysplasia and Gorlin-Goltz. The occurrence of multiple DCs is rare in the absence of these syndromes. A 28-year-old male was referred for pain and mobility of the left mandibular second molar. On radiological examination, follicular enlargement in relation to the unerupted third molar was found. Another unilocular radiolucent area was seen in relation to the right-side unerupted third molar. A provisional diagnosis of multiple odontogenic keratocysts was made; however, the histopathological studies revealed DC on both sides. The patient’s medical history was non-significant, and no associated syndromes were present. Bilateral DCs are rare in the absence of a syndrome, and to date, only 53 cases have been reported in the literature. Here, we report the unusual bilateral occurrence of DCs associated with unerupted mandibular third molars in a non-syndromic patient with a review of the literature for this unusual finding. The one-year follow-up radiograph of the patient showed a favorable osseous formation with no evidence of recurrence of the cysts. A comprehensive radiographic examination, especially for mandibular third molars, is essential for correct diagnosis and management of the lesions. Further-more, systematic clinical examinations should be performed to rule out any associated syndrome.