Journal of Dental School
Volume:32 Issue: 4, Fall 2014

Introduction of fiber-reinforced composites (FRC) greatly enhanced the restoration of fractured anterior teeth. The purpose of this study was to assess the effect of fiber reinforcement on fracture resistance of incisal edge composite restorations of variable thicknesses. Forty extracted sound human maxillary incisors were divided into four groups of 10. Incisal reduction was done by 3mm in groups 1 and 3 and by 4mm in groups 2 and 4. Incisal edge was restored with hybrid composite in groups 1 and 2 and hybrid composite reinforced by two Ribbond fibers in the palatal surface in groups 3 and 4. All specimens were mounted in acrylic blocks, stored in saline solution and thermocycled. The teeth were then subjected to static load by universal testing machine until fracture. The load was applied at 135° angle relative to the tooth surface to an area2mm apical tothe incisal edge at a crosshead speed of 1mm/min. Data were analyzed using Tukey’s test and P≤0.05 was considered significant. The mean fracture resistance was 436 (242) N, 492 (195) N, 992 (275) N and 1080 (236) N in groups 1 to 4, respectively and the difference in this regard among the 4 groups was statistically significant (p=0.000). The mean fracture resistance in group 3 (fiber-reinforced, 3mm thickness) was higher than that in group 1 (no fiber, 3mm thickness). This value in group 4 (fiber-reinforced, 4 mm thickness) was also higher than in group 2 (no fiber, 4mm thickness). The highest fracture resistance was seen in group 4.Thickness of composite had no significant effect on fracture resistance (p=0.347). Application of two Ribbond fibers can significantly increase the fracture resistance of incisal edge composite restorations.

Oral health is one of the basic components of preschool children''s health. Young children completely depend on their parents, specially their mothers, to have an appropriate oral health. Health belief model shows the relationship between some structures related to personal perceptions, barriers and perceived self-efficiency, and behavior. This study aims to determine the oral health care status of children under 4 by their mother according to health belief model in Tehran. In this cross-sectional (descriptive-analytic) study, 200 mothers with children under 4 who visited health care centers under the authority of Shahid Beheshti University of medical Sciences were randomly chosen. A questionnaire which was designed according to health belief model (HBM) was used to collect data. Collected data was analyzed by SPSS software. It was found that only in 10% of the cases knowledge score was favorable. Participants scored 50.85%, 75.93%, 72.23%, 92.06%, 48.2%, 86.31%, 64.07% in knowledge structures, perceived susceptibility, perceived severity, perceived benefits, perceived barriers, self efficiency and behavior respectively. Knowledge structures (p<0.01, r=0. 276), perceived barriers (p< 0/01, r= 0/314) and perceived self efficiency (p<0.01, r=0.269) showed positive correspondence and significant relationship with the oral and dental health behaviors by their mothers. Structures of health belief model could describe 17.9% of behavior variance. Amongst these structures, perceived barriers had more important role. This study estimated that the behavioral status of oral and dental health care of children under 4 by their mothers is moderate. Therefore planning an educational program using behavioral models and theories, such as health belief model is suggested, so that it can increase knowledge and self-efficiency and reduce perceptive barriers to promote children''s oral health.

This prospective study performed to evaluate blood biomarkers alterations with administration of propofol for maintenance of anaesthesia during long oral and maxillofacial surgeries in order to estimate the risk of Propofol Infusion Syndrome (PRIS). This rare syndrome often would be happened in long duration or high dose infusion which is characterized by the combination of metabolic acidosis, acute bradycardia and/or asystole, and rhabdomyolysis and can be fatal. P atients undergoing maxillofacial surgeries (>3h) were the subjects of this quasi experimental prospective clinical trial study. Induction of anaesthesia was performed with midazolam 0.025 mg/kg, fentanyl 2 µg/kg, thiopental sodium 5 mg/kg, and atracurium 0.5 mg/kg. Infusion of propofol was initiated (100 µg/kg/min) for maintenance of anesthesia. Serum potassium level, creatine kinase, lactate and blood PH, were evaluated at baseline, and at 2, 4, 6 hours following the initiation of propofol infusion. Generalized estimating equation was used to evaluate the longitudinal changes for each of the evaluated biomarkers. The relation between the biomarkers and the following factors were appraised by using covariance linear (enter mode) regression analysis: age, gender, weight, administered dose of dexamethasone and epinephrine, duration of surgery, and a history of trauma prior to surgery. A total of 55 participants, 31 women and 24 men, were studied. The mean duration of surgery was 4.8(1) hours. Despite the rise in the level of potassium and creatine kinase and the reduction of blood PH, no case of hyperkalemia or severe metabolic acidosis was observed. Serum lactate level gradually increased to higher than normal in few patients; though did not necessitate any intervention. All alterations were statistically significant. Potassium and creatine kinase level at baseline had relation to pre-surgical trauma. Maintenance of anaesthesia with 100 µg/kg/min propofol along with administration of low-dose epinephrine and dexamethasone did not cause clinically important alterations in blood biomarkers during long-duration maxillofacial surgeries and might not cause PRIS.

Selection of an appropriate shade of composite is critical in achieving an esthetic restoration. Different systems are used to assess and describe color parameters. This study aimed to assess the effect of color and thickness of Filtek Supreme (FS) and Premise (P) composite resins on correction of tooth discoloration. In this in vitro experimental study, 10 anterior teeth with Vita A2 color shade were selected. Composite specimens were fabricated in 0.5 and 0.75 mm thicknesses of FS and P composites. Intact teeth, prepared teeth, prepared teeth with enamel and dentin composite discs on their buccal surfaces, stained teeth and stained teeth with composite discs were photographed using a digital camera under standard conditions and color change (ΔE) at different phases was calculated. The L*, a* and b* color parameters in prepared and unstained teeth were not significantly different from those of intact teeth. In stained teeth, the L* parameter only in prepared and stained teeth with 0.75mm P composite was not significantly different from the L* parameter in intact teeth. Significant differences were seen in other stained teeth. The a* and b* parameters only in prepared and stained teeth with 0.5 mm FS composite were significantly different from those in intact teeth. By increasing the thickness of composite, the color change in comparison with intact teeth decreased in both groups. The results showed that the effect of type of composite, its thickness and their interaction on the color change was significant when using FS and P composites in 0.5 and 0.75mm thicknesses in comparison to intact teeth and the lowest color difference with intact teeth was achieved using 0.75mm thickness of P composite (enamel and dentin).

Osteoporosis is the most common metabolic disease of the bone decreasing bone mineral density (BMD) particularly in postmenopausal women. On the other hand, panoramic radiography has several applications in dentistry. It appears that by calculating some indices on panoramic radiographs, we may be able to predict the risk of osteoporosis in high-risk individuals. The present study was conducted to determine the correlation of skeletal pattern of bone and the morphology of the mandible in osteoporotic patients presenting to the Osteoporosis Clinic of Khatamolanbia Hospital and Imam Khomeini Dental Clinic in Yazd. This descriptive, analytical, cross-sectional study was conducted on 70 women aged over 45 years, whom were selected from the above-mentioned centers. The gonialangle (GA), gonial index (GI), antegonial angle (AA), mental index (MI), antegonial index (AI) and antegonial depth (AD) were calculated on panoramic radiographs of patients and their BMD was measured in the lumbar area and femoral areas using dual X-ray absorptiometry (DXA). The correlation of panoramic indices with BMD was assessed using Spearman and Pearson’s correlation tests. The difference in BMD values in different morphological patterns of the inferior cortex of the mandible was analyzed by Student t-test and in different thicknesses of the cortex using one-way ANOVA. The morphology of the inferior cortex was C1 in 62.9% and C2 in 37.1%. The cortex was thin in 24.3%, moderately thick in 32.9% and thick in 42.9%. Lumbar BMD was 0.92 (0.14) and 0.75 (0.15) g/cm2, in C1 and C2, respectively (p<0.001). Femoral BMD was 0.81 (0.13) and 0.66 (0.09) g/cm2 in C1 and C2, respectively (p<0.001). No significant association was found between GI, AI, GA, AA and AD (based on the estimates made on panoramic radiographs) with the BMD (based on DXA estimates). Use of mandibular cortex indices on panoramic radiographs may be efficient for assessment of osteoporosis. However, further multicenter studies on larger sample sizes are required.

Behavior management of uncooperative children is an important principle in pediatric dentistry. By adopting an appropriate behavior management technique, pediatric dentists can treat patients more effectively and create a positive attitude towards dentistry in them. This study aimed to assess the attitude of parents presenting to the Department of Pediatric Dentistry at Isfahan University, School of Dentistry towards different behavior management techniques used for uncooperative children. This cross-sectional study was conducted in the Department of Pediatric Dentistry at Isfahan University, School of Dentistry. Fifty-four parents watched a film regarding seven popular behavior management techniques namely tell-show-do, voice control, use of passive restraint devices, active restraint (physical restraint by dental personnel or the parents), use of oral sedatives, hand over mouth and general anesthesia. After watching each technique, the parents expressed their opinion regarding the level of acceptability of the respective technique using visual analog scale (VAS). Data were analyzed using the Tukey’s HSD test, repeated measures ANOVA, paired t-test and the Student’s t-test. Of 54 parents, 36 were females and 18 were males aged 23 to 68 years. Of the mentioned techniques, the tell-show-do technique had the highest acceptability (94%). Hand over mouth and use of passive restraint devices had the lowest acceptance (30% and 35%, respectively). Except for the mentioned two, the remaining techniques were well accepted by the parents (52%). No significant association was found between any of the behavior management techniques and age, level of education or occupation of parents. It appears that acceptability of the behavior management techniques has significantly changed over time and advanced pharmaceutical management techniques have gained increasing acceptance.

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most commonly prescribed pain control medications following periodontal surgery. This study aimed to compare the efficacy of three drug regimens namely celecoxib, celecoxib + caffeine and ibuprofen for pain relief following crown lengthening surgery. This randomized, double blind clinical trial was performed on 45 patients aged 20-60 years requiring crown lengthening of maxillary teeth. The subjects were randomly divided into three groups (n=15) receiving ibuprofen (400mg), celecoxib (200mg) and celecoxib (200mg) + caffeine (30mg). Each patient took one dose of the respective medications 30 minutes prior to surgery. Other doses were prescribed 1, 8, 16 and 24 hours after surgery. Pain scores were recorded using visual analog scale (VAS) at 1, 2, 4, 8, 16, 24 and 48 hours post operation. The mean VAS scores were significantly lower in celecoxib + caffeine group than in celecoxib group at 1 and 2 hours after surgery (H1: 2.33 (1.95) vs. 4.47 (2.56), p=0.026) (H2: 2.47 (1.60) vs. 4.80 (2.40), p=0.009). The pain scores were significantly lower in celecoxib + caffeine group than ibuprofen group at 8, 16 and 24 hours after the procedure (H8: 1.80 (1.21) vs. 3.73 (1.94), p=0.012) (H16: 1.07 (1.03) vs. 2.73 (1.87), p=0.012) (H24: 0.47 (0.64) vs. 1.87 (1.25), p=0.004). No significant difference was found in analgesic efficacy of celecoxib and ibuprofen. The combination of celecoxib + caffeine showed higher efficacy than other medications for pain control following crown lengthening surgery. Caffeine may enhance the analgesic effect of celecoxib.

Several medications have been used for sedation in children in dentistry and intra-nasal route has been reported to be an efficient way regarding patient cooperation. The aim of the present study was to compare the changes in physiologic parameters following intra-nasal midazolam and ketamine administration. In this randomized cross-over double-blind trial, 17 uncooperative 3-6 years old children requiring at least two dental treatments were selected randomly and received intra-nasal ketamine (0.5 mg/kg) and midazolam (0.2 mg/kg) prior to the treatment using the other drug in the next visit. Physiologic parameters including blood pressure, heart rate, respiratory rate and O2 saturation were measured and compared during the different time intervals using two way repeated measure ANOVA. The patients showed higher blood pressure and heart rate following ketamine administration compared to midazolam (p<0.001). No significant difference was found between the drugs at different time intervals regarding respiratory rate and O2 saturation. (p> 0.05) In spite of significant differences between midazolam and ketamine regarding heart rate and blood pressure, both drugs can b e used as effective sedative medications without treatment interruption in children.

This study aimed to assess the destructive effects of citric acid, lactic acid and acetic acid produced from the fermentation of foods on primary teeth enamel. This in vitro, experimental study was conducted on 24 sound primary teeth. The teeth were polished with a fine abrasive paper under running water. Tooth pieces measuring 3 × 4 × 3mm were cut out of the teeth and stored in 100% humidity until the experiment. The specimens were divided into 3 groups (n=8) and immersed in acetic acid, citric acid and lactic acid, respectively. The enamel microhardness of specimens was measured by Vickers microhardness tester at baseline and 5 and 30min after immersion in the freshly prepared acid solutions. Repeated measures ANOVA showed that the effect of immersion time on microhardness was significant (p<0.001). Pairwise comparison among 0, 5 and 30 minutes time points using Bonferroni adjustment showed significant differences in microhardness at different time points (p<0.001). Evaluation of the effect of type of acid on microhardness revealed that the microhardness was not significantly different in the three groups of acids (p=0.915). Among the three understudy acids, only the reduction in microhardness from time 0 to 30 minutes was significantly different between lactic acid and acetic acid (p=0.042). Citric acid, lactic acid and acetic acid were all capable of demineralization and reduction of enamel microhardness. A significant difference existed in the demineralization potential of acids (the highest for lactic acid). However, this effect was more significant early after exposure.

Microleakage has always been a problem in restorative dentistry. To decrease microleakage, modern bonding systems, different application methods and sandwich technique have been recommended. The purpose of this study was to assess the microleakage in class V cavities restored with open sandwich technique using self-etch and total-etch bonding systems. In this in vitro study, class V cavities were prepared on the buccal and lingual surfaces of 20 extracted sound human third molars and restored with sandwich technique. Fuji II LC glass ionomer (GI) was applied to the cavity floor. After curing, half the cavities received Single Bond and the other half, Clearfil SE Bond application and were all restored with Z250 composite resin. Specimens were immersed in 2% fuchsin solution for 24 hours. After copious water irrigation, specimens were sectioned and evaluated under a stereomicroscope to determine microleakage. Data were analyzed using the Mann-Whitney U test (p<0.05). The microleakage at the GI-composite interface was less than that at the occlusal and gingival margins; but this difference was not significant. No significant difference was found in microleakage between the two bonding agents in neither of the two layers. The etch & rinse and self-etch systems are similar in terms of microleakage.

Tooth surface undergoes continuous remineralization and demineralization. The aim of this study was to compare the effect of Caseinphosphopeptide-amorphous calcium phosphate (CPP-ACP) paste and Fluoride gel on the microhardness of demineralized enamel lesions. Frothy eight specimens of premolar teeth were chosen and randomly divided to 4 groups of 12. After the initial measurement of micro-hardness the specimens were immersed in demineralizing solution for 4 day and then the measurements were recorded again. Two groups (GL and G3) were treated with CPP-ACP and Fluoride gel respectively according to manufacturer’s instruction. Two other groups (G2 and G4) were treated with CPP-ACP and fluoride gel every week for three months. After the treatments all specimens were taken into PH-cycling and the micro-hardness for each one were measured again. For data analysis, the Repeated Measures ANOVA test and the LSD tests were performed. In each group the percentage of micro-hardness recovery was measured. Repeated Measures ANOVA and LED Test showed that the mean value of hardness was significantly decreased after demineralization in all groups (p=0.01). There was no significant difference in mean hardness value in groups (GL, G3) after treatment (p=0.1, p=0.12) In groups (G2,G4) the mean hardness value were significantly increased (p<0.0001, p=0.1). It is noticeable that the CPP-ACP was significantly more efficient than the fluoride gel. CPP-APC paste and fluoride gel both increase the micro-hardness of enamel when administrated for long time and repeated application.

Orthodontic wires should have high resistance against corrosion in the oral environment. Since the effect of pH on corrosion has been well recognized, this study sought to assess and compare the electrochemical corrosion of orthodontic brackets and wires of different brands in acidic artificial saliva. This in vitro experimental study was conducted on 24 mandibular central incisor brackets of 4 manufacturers namely Dentaurum, American Orthodontics, Shinye and ORJ. The brackets were immersed in acidic artificial saliva along with stainless steel (SS) or NiTi 0.016 round wires for 28 days. All specimens were weighed before and after the experiment by a digital scale. After the experiment, the specimens were evaluated under a light stereomicroscope and specimens with corrosion were further assessed by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX). Two-way ANOVA was used for statistical analysis. The mean corrosion rate (CR) was -1.80, 0.11, 0.05 and -0.93 mpy for Dentaurum, American Orthodontics, Shinye and ORJ brackets, respectively in combination with NiTi wire; these values were 0.46, -0.71, 0.87 and -0.27 mpy, respectively in combination with SS wires; the differences in this regard were not statistically significant (p>0.05). Micrographs showed high corrosion in ORJ brackets followed by Shinye brackets. EDX showed that the combination of ORJ bracket with SS wire had the highest iron (Fe) content and the highest CR. SS brackets manufactured by Shinye and ORJ companies in combination with SS wires showed higher CR in acidic artificial saliva compared to other bracket/wire combinations.

Evidence shows that the powder/liquid mixing ratio recommended by the manufacturers is often not respected when mixing the glass ionomer (GI) powder and liquid, yielding a GI cement with disproportionate powder/liquid ratio. Considering the confirmed effect of powder/liquid ratio on the GI properties, and more importantly, its fluoride release potential, this study aimed to assess the effect of powder/liquid ratio on fluoride release of GI cements. Fuji II, Fuji II LC Improved and Fuji IX GI cements were used in this experimental study. Of each material, three groups with powder 20% less than recommended, the exact recommended ratio and powder 20% more than recommended, were prepared. To assess the fluoride release potential, 45 disc-shaped specimens measuring 2×4mm were prepared (5 per each group). After fabrication, the specimens were immersed in 5 mL of distilled water. The amount of fluoride released into distilled water was measured at days 1 to 7, and also at 13, 14, 15, 28, 29, 30, 58, 59, 60, 88, 89, and 90 days, using Ion Selective Electrode (ISE). After each time of measurement, distilled water was replaced. Data were analyzed using repeated measures ANOVA. Tukey’s post hoc test was used for pairwise comparison of groups and powder/liquid mixing ratio. For pairwise comparison of time points, the Bonferroni adjustment was applied (p<0.05). Based on the results, although the amount of fluoride released from Fuji IX was higher than Fuji II, this difference was not statistically significant (p=0.589). The lowest fluoride release was seen in Fuji II LC and this difference was statistically significant (p<0.05). Change by 20% in the powder/liquid mixing ratio in the three GI cements had no significant effect on fluoride release (p=0.650, p=0.103, p=0.082). Fluoride release from GI was time-dependent and the amount of released fluoride decreased over time. Fuji II LC resin-modified GI (RMGI) released less fluoride than Fuji II and Fuji IX. Also, 20% change in powder/liquid mixing ratio had no significant effect on fluoride release in different groups.

One complication of fixed orthodontic treatment in patients with poor oral hygiene is development of demineralized enamel lesions compromising esthetics. This study aimed to review preventive measures and treatment of white spot lesions (WSLs) in patients with fixed orthodontic appliances. Review of Literature: In this review study, PubMed and Google Scholar databases were searched for articles published during 1964-2013 using the keywords “white spot lesions”, “demineralization”, “mastic gum”, “casein phosphopeptide amorphous calcium phosphate or CPP-ACP”, “chitosan” and “orthodontics”; 96 articles were evaluated. White spot lesions can be prevented by conventional plaque control and adjunct measures such as the use of fluoride-containing compounds, chlorhexidine (CHX), xylitol gums, chitosan compounds and laser. Low-concentration fluoride, CPP-ACP compounds and laser help remineralize these lesions. If not treated, bleaching, microabrasion and tooth restoration are the final solutions.

Congenital fusion of jaws is a rare disorder which is observed in infants and cab ne syndromic and non-syndromic. Limited mouth opening in patients can affect the child growth and cause difficulties in feeding, swallowing and breathing. Case: A In this study, a female infant from Afghanistan, settled in Qom referred to AlZahra maternity with upper and lower fusion jaws is reported. According to clinical and laboratory examinations, infant had no other disorders except the above said disease, and her jaw fusion was non-syndromic. Treatment of this disease in early stages not only is easier, but also can be effective in terms of child’s growth and feeding; because in most cases TMJ ankylosis occurs due to the lack of mobility and loss of function which leads to difficulties in oral operations.