Dental Research Journal
Volume:12 Issue: 6, Nov 2015

Cyclosporine is a selective immunosuppressant that has a variety of applications in medical practice.Like phenytoin and the calcium channel blockers, the drug is associated with gingival overgrowth. This review considers the pharmacokinetics, pharmacodynamics, and unwanted effects of cyclosporine, in particular the action of the drug on the gingival tissues. In addition, elucidates the current concepts in mechanisms of cyclosporine-induced gingival overgrowth. Clinical and cell culture studies suggest that the mechanism of gingival overgrowth is a result of the interaction between the drug and its metabolites with susceptible gingival fibroblasts. Plaque-induced gingival inflammation appears to enhance this interaction. However, understanding of the pathogenesis of gingival overgrowth is incomplete at best. Hence, it would be pertinent to identify and explore possible risk factors relating to both prevalence and severity of drug-induced gingival overgrowth. Newer molecular approaches are needed to clearly establish the pathogenesis of gingival overgrowth and to provide novel information for the design of future preventive and therapeutic modalities.

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age, affecting 4-18% of them. Previous studies also showed that periodontal diseases are associated with different components of the metabolic syndrome. The aim of this study is to determine the association between PCOS and periodontal diseases. A total of 196 women (98 with PCOS and 98 healthy controls) were enrolled. PCOS diagnosis was confi rmed by history, clinical signs, physical examination, laboratory parameters, and ultrasound studies. Both cases and controls were examined by the same periodontist. Periodontal parameters including bleeding on probing (BOP), probing depth, clinical attachment loss (CAL), plaque index, and tooth loss were investigated in all participants. Pregnant women, smokers, individuals with a history of malignancy or osteoporosis, and those taking prophylactic antibiotics for dental procedures or receiving periodontal treatment during the 6-month period before examination were excluded. Data were analyzed using t-test, Chi-square test, and linear regression. Statistical signifi cance was set at P < 0.05. CAL and sites with BOP were signifi cantly higher in women with PCOS (P < 0.05). However, no signifi cant difference was observed in the tooth loss rate between PCOS and non- PCOS participants (P = 0.384). The prevalence of periodontal disease seems to be higher in women with PCOS. This may be related to the role of chronic systemic infl ammation in the pathophysiology of both PCOS and periodontal diseases.

The incidence of dentinal defects may infl uence the outcome of root canal treatment. The aims of this study were to evaluate and compare the incidence of dentinal defects following root canal obturation with two different techniques. A total of 110 mesial roots of human mandibular fi rst molars were selected. Twenty-seven roots were left unprepared as negative controls (NCs). The mesiobuccal canals of 83 roots were prepared using rotary instruments. Twenty-seven roots were left unobturated as positive controls (PCs). Twenty-eight roots were obturated with cold lateral compaction (CLC) technique and the others were obturated with mechanical lateral compaction (MLC) technique. In the CLC and MLC groups, spreader penetration depth was measured by an electromechanical testing machine in canals containing master Gutta-percha cones. After root canal obturation, all the roots were sectioned horizontally at four levels from the apex and evaluated under a stereomicroscope at a magnifi cation of ×40. The presence of dentinal defects was noted. Data were analyzed using the Chi square and t-tests. The number of defects was not signifi cantly different between the CLC, MLC, and PC groups. The CLC, MLC, and PC groups had signifi cantly more defects compared to the NC group. According to the results of this study, the MLC and CLC techniques were the same in producing dentinal defects.

Volume fraction (Vf) and location of internal voids and gaps in relation to material type and cavity dimensions in ultraconservative restorations were investigated in this study. Forty-eight round cavities of 1.3 mm mean diameter and 2.6 mm mean depth were made on buccal and lingual surfaces of recently extracted human teeth. These were fi lled and thermocycled with two low viscosity composites (AeliteFlo LV [AF], PermaFlo [PF]), one high viscosity composite (Aelite aesthetic enamel [AA]) and one glass-ionomer (GCFuji IX GP). X-ray microtomography, following a specifi c procedure, was applied to all cavities before and after their restoration, using SkyScan-1072 microtomographer. Vf percent (Vf%) and location of voids and gaps were recorded and analysed statistically at a = 0.05. Kruskal-Wallis nonparametric analysis of variance, post-hoc analysis, Mann-Whitney test, Spearman’s correlation analysis were used to analyze data. Cavities fi lled with AF and PF showed signifi cantly lower Vf% of voids and gaps than all other restorations (P < 0.05). Only for the cavities fi lled with AA, cavity width and depth was signifi cantly correlated with Vf% (P < 0.05). 50-75% of the fi lled cavities contained internal voids regardless of the restorative material (P > 0.05). The proportion of cavities with gaps at the bottom and side walls was lower in those fi lled with AF and PF (P < 0.05). Cavities fi lled with low viscosity composites presented the lowest amount of internal voids and gaps. Glass-ionomer and high viscosity composite restorative materials showed the highest amount of interfacial gaps. Only in the high viscosity composite restorations the amount of voids and gaps correlated with the cavity depth, width and volume.

Dental anxiety is a relatively frequent problem that can lead to more serious problems such as a child entering a vicious cycle as he/she becomes reluctant to accept the required dental treatments. The aim of this randomized double-blind clinical trial study was to evaluate the anxiolytic and sedative effect of pregabalin in children. Twenty-fi ve children were randomized to a double-blind placebocontrolled crossover clinical trial. Two visits were scheduled for each patient. At the fi rst visit, 75 mg pregabalin or placebo was given randomly, and the alternative was administered at the next visit. Anxiolytic and sedative effects were measured using the visual analogue scale. The child’s behavior was rated with the Frankl behavioral rating scale and the sedation level during the dental procedure was scored using the Ramsay sedation scale. The unpaired, two-tailed Student’s t-test was used to compare the mean changes of visual analog scale (VAS) for anxiety in the pregabalin group with that of the placebo group. A repeated measures MANOVA model was used to detect differences in sedation level in the pregabalin and placebo groups regarding the interaction of 3-time measurements; sub-group analysis was performed using Student’s t-test. The Mann–Whitney U-test was used to analyze the nonparametric data of the Frankl and Ramsay scales. A P < 0.05 was considered signifi cant. The reduction of the VAS-anxiety score from 2 h post-dose was statistically signifi cant in the pregabalin group. From 2 h to 4 h post-dose, the VAS-sedation score increased signifi cantly in the pregabalin group. The child’s behavior rating was not signifi cantly different between the groups. The number of “successful” treatment visits was higher in the pregabalin group compared to the placebo group. Signifi cant anxiolytic and sedative effects can be anticipated 2 h after oral administration of pregabalin without serious side effects.

Nickel–titanium (NiTi) rotary instrumentation carries a risk of fracture, mainly as a result of fl exural (fatigue fracture) and torsional (shear failure) stresses. This risk might be reduced by creating a glide path before NiTi rotary instrumentation. The aim of this study was to compare various root canal parameters with the new WaveOne single-fi le reciprocating system in mesial canals of mandibular molars with and without glide path using cone beam computed tomography (CBCT). One hundred mandibular molar teeth with canal curvature between 20° and 30° were divided into two groups of 50 teeth each. In Group 1, no glide path was created, whereas in Group 2, a glide path was created with PathFiles at working length (WL). In both groups, canals were shaped with WaveOne primary reciprocating fi les to the WL. Canals were scanned in a CBCT unit before and after instrumentation. Postinstrumentation changes in canal curvature, crosssectional area, centric ability, residual dentin thickness, and the extent of canal transportation were calculated using image analysis software and subjected to statistical analysis. Data were analyzed using Student’s t-test and Mann–Whitney U-test (P < 0.05). The mean difference of root canal curvature, cross-sectional area, centric ability, and residual dentin thickness increased, whereas it reduced signifi cantly for canal transportation in Group 2. WaveOne NiTi fi les appeared to maintain the original canal anatomy and the presence of a glide path further improves their performance and was found to be benefi cial for all the parameters tested in this study.

Rheumatoid arthritis (RA) is the most prevalent chronic infl ammatory disease of the joints. It is correlated with periodontal disease due to similar factors that exist in both diseases. The present study assessed the relationship of periodontal disease with RA and juvenile idiopathic arthritis (JIA). In this case-control study, 30 RA and 30 JIA patients along with similar number of matched controls were selected among patients referred to Imam Khomeini Hospital, Tehran, Iran. Periodontal parameters including pocket depth (PD), clinical attachment level (CAL), O’Leary and Bay plaque index (PI) and bleeding on probing (BOP) were determined in cases and controls. Erythrocyte sedimentation rate, number of painful and infl amed joints and severity of disease were evaluated in RA and JIA patients. Mann-Whitney U-test nonparametric, Spearman and Pearson’s correlation coeffi cients, and Chi-square tests were used as statistical analysis (α = 0.05). PD (4.17 vs. 3.6 mm; P < 0.0001), CAL (4.89 vs. 4.18 mm; P < 0.002), percentage of sites with PD >4 mm (58.83% vs. 44.33%; P < 0.002), percentage of sites with CAL >3 mm (74.13% vs. 64.4%; P < 0.001), percentage of sites with BOP (9.67% vs. 6.87%; P < 0.0001) and PI index (85.73% vs. 80.63%; P < 0.0001) were signifi cantly higher in RA patients than controls. In this group, direct and signifi cant correlations were found between serologic fi ndings, disease severity and number of painful and infl amed joints with periodontal factors. In JIA patients, no signifi cant relationships were found between JIA fi ndings and periodontal parameters. Considering the limitations of this study, there was a relationship between RA and periodontal disease. Severity of periodontal disease increases in patients with RA, while no increased risk of periodontal disease or its severity was observed among JIA patients.

Localized alveolar ridge defect may create physiological and pathological problems. Developments in surgical techniques have made it simpler to change the confi guration of a ridge to create a more aesthetic and more easily cleansable shape. The purpose of this study was to compare the effi cacy of alveolar ridge augmentation using a subepithelial connective tissue graft in pouch and modifi ed connective tissue graft technique. In this randomized, double blind, parallel and prospective study, 40 non-smoker individuals with 40 class III alveolar ridge defects in maxillary anterior were randomly divided in two groups. Group I received modifi ed connective tissue graft, while group II were treated with subepithelial connective tissue graft in pouch technique. The defect size was measured in its horizontal and vertical dimension by utilizing a periodontal probe in a stone cast at base line, after 3 months, and 6 months post surgically. Analysis of variance and Bonferroni post-hoc test were used for statistical analysis. A two-tailed P < 0.05 was considered to be statistically signifi cant. Mean values in horizontal width after 6 months were 4.70 ± 0.87 mm, and 4.05 ± 0.89 mm for group I and II, respectively. Regarding vertical heights, obtained mean values were 4.75 ± 0.97 mm and 3.70 ± 0.92 mm for group I and group II, respectively. Within the limitations of this study, connective tissue graft proposed signifi cantly more improvement as compare to connective tissue graft in pouch.

Repair bond strength of different composite resins has been assessed in few studies. In addition, reports on the effi cacy of surface treatments are debated. Therefore, this in vitro study was conducted to evaluate the effect of three surface treatments on two nanocomposites versus a microhybrid composite. In this experimental study, 135 composite blocks (45 specimens per composite) of microhybrid (Filtek Supreme Z250, 3M ESPE, USA), nanohybrid (Filtek Supreme XT, 3M ESPE), and nanofi lled (Filtek Supreme Z350, 3M ESPE) were thermocycled (5000 rounds) and then surface roughened (except in a control group of 9 specimens of three composite types). Each composite type was divided into three subgroups of surface treatments: (1) Bur abrading and phosphoric acid (PA) etching, (2) sandblasting and PA etching, and (3) hydrofl uoric etching and silane application (n = 15 × 9, complying with ISO TR11405). Composite blocks were repaired with the same composite type but of a different color. Microtensile bond strength and modes of failure were analyzed statistically using two-way analyses of variance, Tukey and Chi-square tests (α = 0.05). There were signifi cant differences between three composite resins (P < 0.0001) and treatment techniques (P < 0.0001). Their interaction was nonsignifi cant (P = 0.228). The difference between nanofi lled and nanohybrid was not signifi cant. However, the microhybrid composite showed a signifi cantly higher bond strength (Tukey P < 0.05). Sandblasting was signifi cantly superior to the other two methods, which were not different from each other. Within the limitations of this in vitro study, it seems that microhybrid composite might have higher repair strengths than two evaluated nanocomposites. Among the assessed preparation techniques, sandblasting followed by PA etching might produce the highest bond strength.

Although studies have shown that porcelain veneers are very effi cient for treating discolored teeth, they did not address in particular the minimum thickness of a multilayer IPS e.max Press (IvoclarVivadent, Schaan, Liechtenstein) restoration required to mask discolored tooth. The aim of this study was to determine the minimum thickness of a multilayer porcelain restoration required for masking severe tooth discoloration. A total of 24 disk-shaped multilayer specimens were prepared from IPS e.max Press with the diameter of 13 mm and four different thicknesses (core/veneer: 0.4/0.4 mm, 0.5/0.5 mm, 0.6/0.6 mm and 0.8/0.7 mm). Two backgrounds, C4-shade body porcelain and an opaque background from the selected IPS e.max ceramic itself were fabricated to mimic a discolored or stained natural tooth structure and to determine the masking ability. After applying the resin cement layer (Panavia F2.0) with 0.01 mm thickness on each background, all specimens were measured on both background using a spectrophotometer and values of L*, a* and b* were calculated to determine the color differences (ΔΕ *ab). One-way ANOVA and post-hoc tests of specimen average one-to-one comparison (Tukey HSD) were conducted and P ≤ 0.05 was set as the level of signifi cance. ΔΕ*ab of all groups were within the range of the clinically acceptable color difference (ΔE ≤3.3), thus all the groups could mask the C4 background even group 1 with only 0.8 mm thickness. A trend was shown in the results as by increasing the thickness, ΔΕ*ab is was decreased. The mean ΔΕ* 1*a*b between different thicknesses were statistically signifi cant (P < 0.05) only between group 4 with groups 1 and 2, respectively. Within the limitations of this study, all studied thicknesses could mask the C4 background. However, the minimum thickness of a multilayer porcelain restoration (IPS e.max Press) required for masking severe tooth discoloration was 0.8 mm.

An anti-cariogenic diet containing probiotics can be effective in caries prevention. This animal study compared the effects of milk and yogurt on Streptococcus sobrinus counts and caries score. A total of 36 male rats were infected with S. sobrinus (27,607) and divided into three groups. Group A and B received 200 mL of milk and 100 g of yogurt per day, respectively,and a control group received 2.5 mL of NCP number 2 diet twice daily for 21 days. After killing the animals, their lower left jaws were removed and sonicated to quantify the colonies of S. sobrinus. Dental caries was scored using Keyes technique. Data were analyzed using ANOVA and Kruskal-Wallis,Mann-Whitney and Wilcoxon-Signed Rank tests. Statistical signifi cance was set at P < 0.05. The mean (±standard error of the mean) of S. sobrinus colonies in the milk, yogurt and control groups were determined at 119666.67 (±20733), 46416.666 (±12846) and 163,250 (±33493), respectively. Microbial counts decreased in the yogurt group compared with the milk and control groups (P = 0.004 and P = 0.000; respectively). There were signifi cant differences between caries scores of smooth surfaces in the milk and yogurt groups compared with the control group (P = 0.000 and P = 0.000, respectively). Both milk and yogurt signifi cantly reduced caries score of fi ssured surfaces compared with controls (P = 0.004 and P = 0.000, respectively). Considering the limitations of this study, yogurt administration reduces S. sobrinus counts. In addition, yogurt and milk regimens reduce the caries scores of smooth and fi ssured surfaces.

This study was designed to compare the clinical performance of composite, strip crowns, biological restoration, and composite with stainless steel band when used for the coronal build-up of anterior teeth. A total of 20 patients aged 3-6 years presenting with mutilated primary anterior teeth due to caries or trauma were selected for the study using randomized simple sampling. A total of 52 primary anterior teeth were randomly divided into four equal groups having 13 teeth in each group. Teeth in Group I were restored with composite, in Group II with strip crowns, in Group III with biologic restoration and with stainless steel band reinforced composite in group IV. The restorations were evaluated for color match, retention, surface texture, and anatomic form according to Ryge’s Direct (US Public Health Service) evaluation criteria at baseline (immediate postoperative), after 48 h, 3, 6, and 9 months. The data obtained were statistically analyzed using Chi-square test, and level of signifi cance, that is, P value was determined. At baseline, none of the groups showed any color changes. Other than Group III all other groups showed highly signifi cant changes (P < 0.05) in color after 3 months. Loss of retention was seen in both Groups I and IV after 3 months. After 6 months, retention loss was seen in all the groups except Group II, in which loss was seen after 9 months (P > 0.05). Deterioration in surface texture was exhibited maximum by restorations in Group IV followed by Group I at 3 months. Whereas, no surface changes were seen in Group II and III. Only Group I and IV showed discontinuity in anatomic form after 3 months. After 6 months, except in Group II, discontinuity in anatomic form was observed in all the groups. Discontinuity in anatomic form was seen in all the 4 groups after 9 months although the difference was not signifi cant (P > 0.05). Biological restoration was found to be most satisfying esthetically owing to color compatibility with the patient’s tooth. Thus, it has a great potential to be used as esthetic restorative option in primary anteriors.

This study was designed to assess the microleakage of glass-ionomer (GI), mineral trioxide aggregate (MTA), and calcium-enriched mixture (CEM) cement as coronal orifi ce barrier during walking bleaching. In this experimental study, endodontic treatment was done for 70 extracted human incisors without canal calcifi cation, caries, restoration, resorption, or cracks. The teeth were then divided into three experimental using “Simple randomization allocation” (n = 20) and two control groups (n = 5). The three cements were applied as 3-mm intra-orifi ce barrier in test groups, and bleaching process was then conducted using a mixture of sodium perborate powder and distilled water, for 9 days. For leakage evaluation, bovine serum albumin marker was traced in a dual-chamber technique with Bradford indicator. The Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis. The mean ± standard deviation leakage of samples from negative control, positive control, GI, MTA, and CEM cement groups were 0.0, 8.9 ± 0.03, 0.47 ± 0.02, 0.48 ± 0.02, and 0.49 ± 0.02 mg/mL, respectively. Statistical analysis showed no signifi cant difference between three experimental groups (P > 0.05). It is concluded that GI, MTA, and CEM cements are considered as suitable intra-orifi ce barrier to provide coronal seal during walking bleaching.

There have been numerous researches on elastomeric ligatures, but clinical conditions in different stages of treatment are not exactly similar to laboratory conditions. The aim of this in vitro study was to simulate clinical conditions and evaluate the effect of three stretching patterns on the amount of force, tensile strength (TS) and extension to TS of the elastomers during 8 weeks. Forces, TS and extension to TS of two different brands of elastomers were measured at initial, 24 h and 2, 4, and 8-week intervals using a testing machine. During the study period, the elastomers were stored in three different types of jig (uniform stretching, 1 and 3 mm point stretching) designed by the computer-aided design and computer-aided manufacturing technique in order to simulate the different stages of orthodontic treatment. The elastomeric ligatures under study exhibited a similar force decay pattern. The maximum force decay occurred during the fi rst 24 h (49.9% ± 15%) and the amount of force decay was 75.7% ± 8% after 8 weeks. In general, the TS decreased during the study period, and the amount of extension to TS increased. Although the elastic behavior of all ligatures under study was similar, the amount of residual force, TS and extension to TS increased in elastomers under point stretching pattern.