Cavity Preparation by Laser in Primary Teeth: Effect of 2 Levels of Energy Output on the Shear Bond Strength of Composite Restoration to Dentin

Introduction: One of the main applications of laser in dentistry is the removal of dental caries and preparation of restorative cavities. The morphology and wettability of laser prepared surfaces are different from that of those prepared with conventional method which may affect the quality of the adhesive potential of bonding agents in these surfaces. This study aimed to assess the shear bond strength of a total-etch and self-etch adhesive system to primary tooth dentin prepared by two different energy densities of Er:YAG laser in comparison with surfaces prepared by bur.Methods: A total of 60 human primary second molars extracted for orthodontic purposes were selected and randomly divided into 3 main groups of equal (n = 20). Group A: Preparation of dentin surface by bur; group B: Preparation of dentin surface by laser with 300 mJ energy level; group C: Preparation of dentin surface by laser with 400 mJ energy level. In each of the main groups, the teeth were randomly assigned to 2 subgroups. Composite resin material was bonded with the total-etch adhesive system in subgroups A1, B1, and C1 and with the self-etch adhesive system in subgroups A2, B2, and C2. The samples were thermo-cycled, and composite restorations shear bond strength was measured in MPa. Data were analyzed using two-way analysis of variance (ANOVA), and P values less than 0.05 were considered statistically significant.Results: The highest and the lowest shear bond strength values were observed in group A2 (Preparation by bur- Composite resin material bonded by Clearfil SE Bond) and group C2 (Preparation by laser with 400 mJ energy level - Composite resin material bonded by Clearfil SE Bond), respectively. The results showed no statistically significant differences between the study subgroups (P > 0.05).Conclusion: It is concluded that in terms of shear bond strength to dentin, Single Bond and Clearfil SE Bond adhesive agents adequately perform in primary tooth dentin prepared by Er: YAG laser with energy levels of 300 and 400 mJ and frequency of 10 Hz

Sealant Microleakage After Using Nano-Filled Bonding Agents on Saliva-Contaminated Enamel

Objective: The efficacy of correctly applied fissure sealants has been revealed in the prevention of caries. Saliva and moisture contamination of the etched enamel surface before sealant placement can decrease the bonding strength of the sealant to the enamel. The aim of this study was to test the new bonding agents containing nano-fillers in order to reduce the negative effect of saliva contamination on the sealant micro leakage.Materials and Methods: Seventy five sound human premolars were randomly assigned to five equal groups as follows: Group A: etching, sealant; Group B: etching, saliva contamination, sealant; Group C: etching, saliva contamination, Single bond, sealant; Group D: etching, saliva contamination, Adper Single bond 2, sealant; Group E: etching, saliva contamination, N Bond, sealant. The samples were thermo-cycled and immersed in basic fuchsine 0.5% by weight. Then, the teeth were sectioned bucco-lingually and parallel to the long axis into two segments. Finally, the length of dye penetration at the sealant-tooth interface was scored according to a four-point scale.Results: Micro-leakage was higher in group B compared to the other groups, while there were no differences among the evaluated dentin adhesives.Conclusion: The use of nano-filled bonding agents as an intermediate layer between the etched enamel and the sealant can reduce sealant micro-leakage after saliva contamination at the level of the uncontaminated enamel

Locating Mandibular Foramen in Children with Mandibular Retrognathism in Mixed Dentition

Background and aims. One of the most common reasons forthe inferior alveolar nerve block anesthesia failure is the variation in mandibular foramen location. The aim of this study was to assess the location of mandibular foramen in chil-dren with mandibular retrognathism in comparison to children with normal skeletal occlusion in the mixed dentition. Materials and methods. One hundred and twenty panoramic radiographs of patients in mixed dentition period, undergo-ing orthodontic treatment, were selected based on inclusion criteria, skeletal occlusion and stage of dental development. The radiographs were divided into two groups: I: 60 panoramic radiographs of patients with normal skeletal occlusion (15 in each of the Hellman dental age stages); II: 60 panoramic radiographs of patients with mandibular retrognathism (15 in each of the Hellman dental age stages). The radiographs were traced and the linear distance from the mandibular foramen to the borders of the mandibular ramus and its angular position were identified. The measurements were compared between the two groups and among the four dental age groups by t-test, ANOVA and post hoc tests. Results. No statistically significant differences werefound between the patients with normal skeletal occlusion and patients with mandibular retrognathism (P>0.05). Statistical tests showed significant differences in the vertical location of mandibu-lar foramen and gonial angle between the four dental age groups (P<0.05). Conclusion. Mandibular retrognathism does not have a significant impact on the location of the mandibular foramen in the mixed dentition period. The child’s dental age would be considered in the localization of the mandibular foramen

The effect of Filmed modeling on the anxious and cooperative behavior of 4-6 years old children during dental treatment: A randomized clinical trial study

Background: The aim of this study was to evaluate the effect of Filmed modeling in comparison with commonly used Tell-Show-Do technique (T.S.D) on the anxious and cooperative behavior of 4-6 years old children during dental practice. Materials and Methods: Forty six children aged 4-6 years were enrolled in this study and randomly allocated into two groups. Group I: At the first visit, the procedure of Tell-Show-Do, and at the second visit, the treatment procedures were performed by the dentist for the children. Group II: At the first visit, children watched a film consisting of the procedure of Tell-Show-Do performed on a child model. At the second visit, treatment procedures were performed. In both groups, during the treatment procedure, index of heart rate was measured and behaviors of children were recorded. The children′s anxious and cooperative behaviors on the recordings were quantified according to Venham and Frankl rating scales, respectively. The data were compared between two groups using T-test method. All statistical references were made at 0.05. Results: There were no statistically significant differences in heart rate measures, clinical anxiety and cooperative behavior scores of children between the two groups (P = 0.6). Conclusion: Filmed modeling can be an efficient alternative method to Tell-Show-Do technique in pre-appointment preparation of the 4-6 years old children during dental treatment

Oral health and school performance in elementary students: A cross-sectional study in a group of Iranian students, Tehran, Iran

BACKGROUND AND AIM: Dental health plays a key role in the overall health status and quality of life in children. Consequences of dental diseases in children may result in impairments of daily life activities. The aim of this study was to assess the relationships between dental health and educational performances in elementary students. METHODS: A total of 300 elementary students from the second to fifth grades in ninth district of Tehran, Iran, were included in this study according to inclusion criteria. Questionnaire gathering information about the students’ demographic background, medical and dental histories was sent to their parents. The students’ academic performances were assessed based on the school absence in relation to dental problems, their school grades and doing homework. Oral health status was assessed based on the World Health Organization (WHO) standards using caries and oral hygiene indices. Data were analyzed by the Pearson’s correlation and linear regression analysis. All statistical levels were made at 0.05 for the Pearson’s correlation and 0.1 for linear regression analysis. RESULTS: School test grades and school absences due to dental problems were statistically associated with oral hygiene index (OHI) of the students (P = 0.010 and P = 0.040, respectively). The indices of dental caries in primary or permanent teeth were not significantly associated with school performances (P ≥ 0.140). The analysis revealed that the factors i.e., housing status and living with the parents are statistically associated with the oral health indices (P = 0.050 and P =0.080; respectively) and on the other hand with school performances (P = 0.020 and P = 0.010; respectively). CONCLUSION: Children with poorer oral health status were more likely to perform poorly in school. Socio-economic status of the students affects negatively both school performances and oral health care. Also, oral health status and dental problems may cause deterioration in educational conditions. KEYWORDS: Students, Oral Health, Dental Caries, School, Performanc

Fracture Strength of Severely Damaged Primary Anterior Teeth after Restoration with Composite Resin and Resin-Modified Glass Ionomer Cement

Background and Aim: Restoration of primary anterior teeth with severe caries extending to the gingival margin is challenging for many clinicians especially in uncooperative children. Resin modified glass ionomer cements (RMGICs) can be suitable for use in such cases since they require fewer application steps than composite resins. This study aimed to assess the fracture strength of severely damaged primary anterior teeth after their coronal build-up using RMGIC and composite resin. Materials and Methods: This in vitro, experimental study was conducted on 40 primary teeth that met our inclusion criteria. After decoronization, they were cleaned and root canals were filled. In the coronal cavity, one layer of base was applied and an undercut was created in the canal wall above the base. The teeth were divided into two groups of 20 for coronal restoration. In group 1, etching, bonding, intracanal post fabrication and restoration with composite resin were carried out. In group 2, conditioning, intracanal post fabrication and restoration with Fuji II LC RMGIC were performed. After thermal cycles, fracture strength of teeth was measured and compared in the two groups using t-test. Results: Fracture strength of teeth was not significantly different between two groups restored with composite resin (5.03±2.30 MPa) and RMGIC (5.67±2.38 MPa) (P>0.05) Conclusion: In the post and crown build up of severely damaged primary anterior teeth with severe caries extending to the gingival margin, Fuji II LC RMGIC can be used as an alternative to composite resin especially in uncooperative children or treatment under general anesthesia

The Effect of Parental Presence on the 5 year-Old Children's Anxiety and Cooperative Behavior in the First and Second Dental Visit

Objective: One of the most significant problems in pediatric dentistry is behavioral resistance of preschool children in the first visit. There is a debate on parental presence in operation room. The purpose of this study was to evaluate the Iranian 5-year-old children's behavior including anxiety and cooperation relative to parental presence in the first and second dental appointments. Methods: The study was conducted on sixty seven 5-year-old children selected according to inclusion criteria and randomly divided into two subgroups. Children in group I were visited in parent's presence and in group II in parent's absence. Before the child's first dental visit, parents were interviewed. Forty eight of the children receiving the initial examination were recalled for a second visit. The children's responses during the Holst procedure of the first visit and restorative second visit were assessed using a combination of two measures including heart rate and clinical behavior. The dentist-patient interactions were regulated by standardized scripts and recorded on videotape. Then, the behavior of the child on the recording during each visit was quantified by two pediatric dentists independently according to Venham 6-point rating scale and Frankle 4-point rating scale. Findings: There were no significant differences between the heart rate measures of children in group I and II in the first and second visit (0.67, 0.8 respectively). There were also no significant differences between the clinical anxiety scores of children in the two groups in the first and second visit (0.98, 0.42 respectively). Moreover, there were no significant differences between the clinical cooperation scores of children in group I and group II in the first and second visit (0.88, 0.40 respectively), neither were there any significant differences between response measures of each child between two visits (P>0.05). In addition, there were no significant differences related to sex, parental education and dental experiences (P>0.05). Conclusion: Parental presence or absence doesn't affect an Iranian 5-year-old child's anxiety on the first and second dental visit, as well as an Iranian 5-year-old child's cooperation on the first and second dental visit