Dental Research Journal
Volume:12 Issue: 3, May 2015

Organ transplantation is a widely undertaken procedure and has become an important alternative for the treatment of different end-stage organ diseases that previously had a poor prognosis. The field of organ transplant and hematopoietic stem cell transplant is developing rapidly. The increase in the number of transplant recipients also has an impact on oral and dental services. Most of the oral problems develop as a direct consequence of drug-induced immunosuppression or the procedure itself. These patients may present with oral complaints due to infections or mucosal lesions. Such lesions should be identified, diagnosed, and treated. New treatment strategies permit continuous adaptation of oral care regimens to the changing scope of oral complications. The aim of this review is to analyze those oral manifestations and to discuss the related literature.

The aim of this study was to compare the shear bond strength of four one step self-etch adhesives with different pH values to enamel and dentin. In this in vitro study, 200 bovine permanent mandibular incisors were used. Four one-step self-etch adhesives with different pH values were tested both on enamel and on dentin: Adper™ Easy Bond Self-Etch Adhesive (pH = 0.8-1), Futurabond NR (pH=2), G-aenial Bond (pH = 1.5), Clearfi l S3 Bond (pH = 2.7). After adhesive systems application, a nanohybrid composite resin was inserted into the bonded surface. The specimens were placed in a universal testing machine. The shear bond strength was performed at a cross-head speed of 1 mm/min until the sample rupture. The shear bond strength values (MPa) of the different groups were compared with analysis of variance after that Kolmogorov and Smirnov tests were applied to assess normality of distributions. P < 0.05 was considered as signifi cant. In enamel shear bond strength, the highest shear bond strength values were reported with Futurabond NR (P < 0.01); however, no signifi cant differences were found with Clearfi l S3 Bond. The others adhesive systems showed lower shear bond strength values with signifi cant differences between them (P < 0.05). When comparing the dentin shear bond strength, the lowest shear bond strength values were reported with Clearfi l S3 Bond (P < 0.05), while there were no signifi cant differences among the other three products (P > 0.05). The pH values of adhesive systems did not infl uence signifi cantly their shear bond strength to enamel or dentin.

Low-level laser therapy (LLLT) has shown a promising effect in ameliorating symptoms of rheumatoid arthritis (RA). The aim of this investigation was to compare the early and late antiinfl ammatory effects of LLLT and betamethasone in RA. In this animal experimental study, after inducing a model of RA in temporomandibular joint (TMJ) of 37 Wistar rats using adjuvant injection, they were randomly distributed into three experimental groups of 12 animals each: (1) LLLT group; (2) steroid group which received a single dose of betamethasone systemically; and (3) positive control group, which did not receive any treatment. One rat served as the negative control. Half of the animals in all the experimental groups were sacrifi ced on the 21st day after RA induction (early phase), and the other half were sacrifi ced 2 weeks later (late phase). Then, the severity of TMJ infl ammation was assessed histologically in each group on a semi-quantitative scale. Kruskal-Wallis and Mann-Whitney tests were used to compare differences (α = 0.05). The LLLT and steroid groups showed signifi cantly (P < 0.05) lower infl ammation mean scores in both early (5.66 [±1.86] and 1.66 [±1.21], respectively) and late phases of evaluation (1.16 [±1.47] and 6.50 [±1.04], respectively) compared to positive control group in early and late stages of assessment (11.66 [±3.50] and 8.66 [±1.36], respectively). However, the best results (P < 0.005) were achieved in early phase of the steroid group as well as late phase of the LLLT group. Within limitations of this study, it may be concluded that LLLT method has a long-term promising effect on reducing infl ammation severity of TMJ similar to betamethasone in earlier stages.

Despite widespread clinical uses of resin-modifi ed glass-ionomers (RMGIs), their sealing ability is still a concern. This study evaluated the effect of delayed light activation (DLA) of RMGI on marginal sealing in differently pretreated cavities. In this in vitro study, two standardized Class V cavities were prepared on the buccal and lingual surfaces of 56 sound maxillary premolars at the cementoenamel junction. The cavities were randomly divided into eight equal groups. In groups 1-4 (immediate light activation [ILA]), no pretreatment (negative control [NC]) and three surface pretreatments were used, respectively as follows: Cavity conditioner, Vitremer primer, cavity conditioner plus and casein phosphopeptideamorphous calcium phosphate (CPP-ACP). Fuji II LC (GC, Japan) was prepared and placed in the cavities and immediately light-cured according to manufacturer’s instructions. In groups 5-8 (DLA), the same pretreatments were applied, respectively. After placing Fuji II LC in the cavities, the restorations were light-cured after a 3-min delay. After fi nishing the restorations, the specimens were placed in water for 1-week and thermocycled. Microleakage scores were determined using the dye penetration technique. Kruskal–Wallis test and Mann–Whitney U-test were used to analyze the obtained data (α = 0.05). At the dentin margins, DLA resulted in a lower microleakage for no treatment (NC), cavity conditioner and cavity conditioner plus ACP-CPP pretreatments groups (P ≤ 0.004); however, no difference was observed for Vitremer group (P > 0.05).At the enamel margins, no difference was observed between DLA and ILA for all groups (P > 0.05); only NC group exhibited a lower microleakage in case of DLA (P = 0.007). Delayed light activation of RMGI may lead to different effects on marginal sealing, depending on pretreatment procedures used in the cavity. It might improve dentin sealing when no treatment and conditioner alone or with CCP-ACP is used.

The most favorable feature of nickel-titanium (Ni-Ti) alloys in orthodontics is producing constant forces in a wide deformation range. Ni-Ti closed coils produce compressive strength and can be used for several purposes such as space closure. The aim of this study was to evaluate the effects of the aging process (temperature changes and prolonged strain) on Ni-Ti closed coils and to assess the effects of preactivation on forces generated by these coils. A total of 60 Ni-Ti closed coils (G&H Wire Co., Indiana, USA) were divided into four groups (n = 15). Two groups were kept in room temperature and two were incubated in 37°C in normal saline for 45 days. All the samples were extended to 30% of their original length. One group of the incubated coils and one group of room temperature coils were preactivated the same amount of 30%. The incubated groups also received 1000 thermocycles on days 22 and 45. The unloading forces were measured by a universal testing machine on days 0, 22 and 45. The data were analyzed using SPSS. Signifi cance was set at 0.05. The unloading forces of the Ni-Ti closed coils was not affected by prolonged heat and moisture either in preactivated groups (P = 0.8) or the nonpreactivated groups (P = 0.6). Furthermore, preactivation had no signifi cant effect on the unloading forces of Ni-Ti closed coils (P = 0.7). Within the limitations of this study, both aging process and preactivation do not affect on mechanical properties of nickel-titanium closed coil springs. Preactivation had no effect on the forces generated by Ni-Ti closed coils.

The issue of a possible malignant transformation in the lesions like epithelial dysplasia and oral lichen planus (OLP) is a matter of serious controversy. The purpose of this study was to suggest the malignant transformation rate in OLP and oral epithelial dysplasia (OED) by using immunohistochemical expression of the tumor markers Ki-67, p53, BCL-2, and BAX.This was a cross-sectional study carried out among 70 samples, including 10 samples from normal healthy mucosa categorized into Group 1, Group 2 (30 OLP), and Group 3 (30 OED) samples. Five sections (4 μm thick) were obtained and stained with monoclonal antibodies such as Ki-67, p53, BCL-2, and BAX and analyzed for number of positive cells and also for intensity of staining. Statistical analysis was done using Mann-Whitney U-test (P < 0.05). Significant results were found only for expressions of Ki-67, p53, BCL-2 markers in both study groups (P < 0.05). In these groups, the intensity of staining was mostly mild to moderate for all studied tumor markers. In this study, subjects with an average positive IHC expression of Ki-67, p53, BCL-2, and BAX markers in normal mucosa was about 22.5%, which was significantly lower when compared with OLP (54.9%) and OED (64.9%). The high propensity for malignant transformation in OED followed by OLP suggests that a wide range of inherent and extrinsic factors contribute to the disease progression and malignant transformation.

Reusing orthodontic mini-screws would reduce treatment cost and lead to more use of mini-screws and improvement of orthodontic treatments. This study has assessed the effects of reprocessing and reusing the titanium mini-screws on their maximum insertion, removal and fracture torque (FT). In this experimental study, 20 titanium mini-screws (1.6-mm × 8 mm) were randomly divided into two equal groups. In the test group, the screws were fi rst sterilized by autoclave and then their FT was assessed. In the control group, FT was assessed after 5 times of insertion, cleaning, processing (37% phosphoric acid for 10 min, 5.25% sodium hypochlorite for 30 min) and sterilizing with autoclave. The maximum insertion and removal torque values were compared using the repeated measure ANOVA and the FT data were analyzed by the t test. The data were analyzed using the SPSS software (version 13.0) and the signifi cance was set on 0.05. The paired t-test for maximum insertion torque (MIT) showed that MIT1 was signifi cantly lower than other MIT values (P = 0.02) and also MIT2 was signifi cantly higher than MIT5 (P = 0.01), but other MIT values had no signifi cant differences. The paired t-test for maximum removal torque (MRT) showed that only MRT2 was signifi cantly higher than other MRT values (except MRT1) (P = 0.046). Regarding FT, the t-test showed that there was no signifi cant difference between FT0 and FT5 (P = 0.485). Within limitations of this study, fi ve time insertion, cleaning, processing and steam sterilization had no signifi cant negative effect on insertion, removal and FT of the mini screws.

Dental anxiety and fear are major complications for both patient and dental care provider. The purpose of this study was to assess the prevalence of dental anxiety and fear in patients who referred to Isfahan Dental School and their relation to their age, gender, educational level, past traumatic experiences and frequency of dental visits. In this cross-sectional study, 473 patients were provided with a questionnaire including three sections. First section contained questions concerning their age, gender, educational level, frequency of dental visits, reasons for irregular attendance and existence of past traumatic experiences. Second section comprised a Farsi version of Modifi ed Dental Anxiety Scale (MDAS); and third included a Farsi version of dental fear survey (DFS). Data were analyzed by t-test, ANOVA, Pearson and Spearman correlation tests. The prevalence of dental anxiety among the study population was 58.8%. No correlation was found between age and MDAS (r = −0.08, P = 0.07) and DFS (r = −0.03, P = 0.53). Women demonstrated higher anxiety (P < 0.001) and fear (P = 0.003). Education had no signifi cant effect on dental anxiety (r = −0.046, P = 0.32) and dental fear (r = −0.017, P = 0.79). Previous traumatic experiences were found to result in elevated anxiety and fear (P < 0.001). There was an inverse relationship between frequency of dental attendance and anxiety (r = −0.128, P = 0.008). Within the limitations of this study, anxiety associated with dental treatment was widespread in the study population. Dental fear and anxiety were not affected by age or education level. Dental fear and anxiety were higher in women. In addition, people who visited the dentist more regularly and individuals without previous traumatic dental experiences were less anxious.

At the end of fi xed orthodontic treatment, the remnant of adhesive should be eliminated from the tooth surface. The purpose of this study was to compare the effect of three methods of removing adhesive on enamel surface roughness, dental pulp t emperature, and also on the time spent. The brackets on 90 extracted teeth were debonded using bracket removal pliers. A thermocouple sensor was fi tted on the buccal wall of the pulp chamber through access cavity to measure thermal changes during adhesive removal. The residue of adhesive was eliminated from enamel surface of teeth by either tungsten carbide bur, erbium-doped yttrium aluminum garnet laser, or fi ber reinforced composite bur. Scanning electron micrographs images were taken to assess the roughness of enamel surface. The time spent for adhesive removal was recorded as well. Chi-square test was used to evaluate the remnants of adhesive and enamel surface roughness; t-test and also repeated measurement analysis of variance were applied at P < 0.05 to compare the thermal changes of the pulp chamber and time spent between the methods of surface treatment. The results of surface roughness were signifi cantly different (P < 0.001). The pulp temperature c hanged signifi cantly (P < 0.001). Tungsten carbide bur increased the temperature by 5.5°C signifi cantly slower than reinforced composite bur (P = 0.004), however removed the adhesive residue faster than two other methods although not signifi cantly (P = 0.069). Within the limitations of this study, fi ber reinforced composite bur created the smoothest enamel surface while Er:YAG laser the roughest. Tungsten carbide and composite burs generated more heat compared to Er:YAG laser. In addition, tungsten carbide bur was the fastest and Er:YAG laser the slowest devices to remove adhesive residue.

Regarding the need for determining the cephalometric norms for each population and the advantages of proportional analyses, we evaluated the variables of McNamara and Schwartz analyses and their relation in a pilot study on 6-17 years old Iranian students and provided formulas, which show these relations. In this descriptive-analytical study, a tatal of cephalometric radiographs from the archive documents of Orthodontic Department of Isfahan Dental School was selected and traced. The variables of McNamara and Schwartz analyses were investigated. The data were analyzed by t-test and linear regression and Spearman correlation coeffi cient tests using SPSS 12 software, and the signifi cance was set at 0.05. Then, a formula was suggested for predicting the relation between the jaws, cranium and face. The variables measured in this study were signifi cantly different between the genders (P < 0.05), except for Co-Gn (P = 0.055), and they were higher in boys. All variables signifi cantly increased (P < 0.05) with age from 6 to 17 years. The formulas presented in this study can be used for calculating the amount of PNS-APmax, Go-APman and the Co-Gn, anterior nasal spine-menton in the Iranian population. Within the limitation of this study, the formula presented in this study might be considered to predict the relation between jaw dimensions and cranial base and facial dimensions in the Iranian population.

The purpose of this study was to evaluate the effect of light-curing time on the shear bond strength (SBS) of two orthodontic color-change adhesives (CCAs). A total of 72 extracted premolars were randomly assigned into 6 groups of 12 teeth each. Subsequent to primer application, a metal bracket was bonded to the buccal surface using an orthodontic adhesive. Two CCAs (Greengloo and Transbond Plus) were tested and one conventional light-cured adhesive (Resilience) served as control. For each adhesive, the specimens were light-cured for two different times of 20 and 40 s. All the specimens underwent mechanical testing using a universal testing machine to measure the SBS. Adhesive remnant index (ARI) was used to assess the remnant adhesive material on the tooth surface. All statistical analyses were performed using SPSS software. The signifi cance level for all statistical tests was set at P ≤ 0.05. The SBSs of the tested groups were in the range of 14.05-31.25 MPa. Greengloo adhesive showed the highest SBS values when light-cured for 40 s, and Transbond Plus adhesive showed the lowest values when light-cured for 20 s. ARI scores of Transbond Plus adhesive were signifi cantly higher than those of controls, while other differences in ARI values were not signifi cant. Within the limitations of his study, decreasing the light-curing time from 40 to 20 s decreased the SBS of the tested adhesives; however, this decline in SBS was statistically signifi cant only in Transbond Plus adhesive

Providing a cross-sectional image is essential for preimplant assessments. Computed tomography (CT) and cone beam CT (CBCT) images are very expensive and provide high radiation dose. Tangential projection is a very simple, available, and low-dose technique that can be used in the anterior portion of mandible. The purpose of this study was to evaluate the accuracy of tangential projection in preimplant measurements in comparison to CBCT. Three dry edentulous human mandibles were examined in five points at intercanine region using tangential projection and CBCT. The height and width of the ridge were measured twice by two observers. The mandibles were then cut, and real measurements were obtained. The agreement between real measures and measurements obtained by either technique, and inter- and intra-observer reliability were tested. The measurement error was less than 0.12 for tangential technique and 0.06 for CBCT. The agreement between the real measures and measurements from radiographs were higher than 0.87. Tangential projection slightly overestimated the distances, while there was a slight underestimation in CBCT results. Considering the low cost, low radiation dose, simplicity and availability, tangential projection would be proper for preimplant assessment in edentulous patients when limited numbers of implants are required in the anterior mandible, and there is no need for more complicated image modalities.

Cyclo-oxygenase-2 (COX-2) is an early response gene that is induced by growth factors, oncogenes and carcinogens and its expression is increased in various tumors. Increased expression of COX-2 plays a signifi cant role in the development and growth of tumors by interfering in biological processes such as cell division, cellular immunity, cell adhesion, apoptosis, and angiogenesis. This study aimed to investigate the immunohistochemical expression of COX-2 in keratocystic odontogenic tumor (KOT) in comparison with ameloblastoma and dentigerous cyst with regards to different clinical behavior and histopathological features of these lesions. Paraffi ned blocks of 45 cases including 15 cases of dentigerous cyst, 15 cases of KOT and 15 cases of ameloblastoma were stained with immunohistochemical method for COX-2. Five high-power fi elds of each sample were evaluated to determine the percentage of stained cells and the intensity of staining. Degree of immunoreactivity was obtained from the sum of two. Statistical evaluation was performed by the Kruskal-Wallis and ANOVA Mann-Whitney test (P < 0.05). Overexpression of COX-2 in ameloblastoma and KOT was observed compared with dentigerous cyst (P < 0.001). However, no signifi cant difference was observed between the expression of COX-2 in ameloblastoma and KOT (P = 0.148). The COX-2 expression in odontogenic tumors such as ameloblastoma and cystic neoplasm with aggressive behavior such as KOT increases. However, it does not seem that COX-2 affects the development and growth of cysts with noninvasive behavior like dentigerous cyst.

Traumatic injuries in the primary dentition pose major challenges for management. This emergency treatment requires proper planning so as to achieve favorable results. Trauma causing severe dentoalveolar injuries, especially in children, needs an interdisciplinary approach so as to retain normal functional anatomy for that age. This article describes a clinical innovative technique, which utilizes a resorbable membrane in management of pediatric dentoalveolar trauma. The membrane was shaped to cover the multiple alveolar bone fracture, thereby favoring the healing of the bone defects. The use of this resorbable membrane maintained a secluded space for the bone growth and prevented overgrowth of the soft tissue in the region of the defect. This resulted in uneventful healing leading to well-maintained functional bone contour, which further favored the esthetic rehabilitation as well as protected the underlying permanent tooth buds.