Journal of Dental Medicine

Statement of Problem: Microleakage presents the major cause for restorations failure in the oral cavity resulting in postoperative sensitivity, pulp irritation and secondary caries formation.

Aim: The aim of this study was to compare two dentinal adhesive systems of fifth generation and copalite varnish in reducing microleakage of amalgam restorations in primary teeth.
Materials and Methods: In this in-vitro study, 100 class V amalgam restorations were prepared on the buccal or lingual surfaces of primary molar and canine teeth. Samples were randomly divided into four groups (25 samples each). No liner was used for the first group and the second group restorations were lined with copalite varnish. Two dentin adhesives, called Syntac C and Single Bond, were used for the third and fourth groups, respectively. At the next stage, the samples were immersed in 5% fuschin solution for 24 hours, then sectioned buccolingually, and examined under a stereomicroscope for microleakage evaluation.
Results: There was a significant difference between four groups statistically (PO.000I), Comparing four groups, the first and fourth ones, demonstrated the most and the least microleakage, respectively.

Conclusion: The present study showed that new dentinal adhesive systems caused microleakage reduction in amalgam restorations of primary teeth.

Background and Aim: Pulpotomy is one of the routine methods for pulp therapy of primary teeth. At present it is a fact that ideal agent for this has not been discovered. The aim of this study was to compare the clinical and radiographic success rates of electrosurgical pulpotomy versus formocresol pulpotomy in human primary molar teeth.

Materials and Methods: In this clinical trial study, pulpotomy was performed on 68 primary molars in children aged from 5 to 10 years. The teeth were treated using either a conventional formocresol (35 teeth), or electrosurgical technique (33 teeth). Following the pulpotomy procedure, the teeth were evaluated regarding clinical and radiographic success for 3, 6 and 9 months periods. The teeth were evaluated clinically and radiographically for the presence of pain, abscess, fistula, mobility, internal and external resorption and radiolucency. Finally clinical and radiographic data were collected and analyzed with Fisher exact test using P<0.05 as the limit of significance.

Results: After 9 months follow up, the clinical and radiographic success rates for the electrosurgery group were 96% and 84% respectively and for formocresol group, 100% and 96.8% respectively. There were no statistically significant differences between the success rates for the two groups (P>0/05).

Conclusion: Although electrosurgical pulpotomy is a nonpharmacological and easy to use technique, further investigations with longer evaluation periods are suggested.

Background and Aim: One of the unique properties of MTA is its setting ability in presence of moisture. The sealing ability of MTA used as a root-end filling was shown to be unaffected by the presence of blood, in vitro. It has been recommended that, because of MTA ability to set in the presence of blood, there is no need to dry the perforation site before MTA placement. On the other hand, based on an in vitro study, it is recommended that hemorrhage be controlled at the perforation site and blood be removed from the perforation walls before placement of tooth-colored MTA. Blood contamination may also affect the crystalline structure of MTA. The microhardness of a material is influenced substantially by some fundamental properties of the material such as crystal structure stability. Thus, it can be used as an indicator of the setting process. It can also indicate the effect of various setting conditions on the overall strength of a material. The aim of this study was to evaluate the effect of blood contamination on microhardness of white and gray MTA as an indicator of their setting process.

Materials and Methods: In groups 1 and 2 each material has been mixed with distilled water according to manufacturer^,s instruction (No contamination groups). In groups 3 and 4 samples were prepared like groups 1 and 2 but the surface of material placed in contact with blood (Surface blood contamination groups). Samples of groups 5 and 6 were mixed with blood instead of distilled water and also the surfaces of the materials were placed in contact with blood (Mixed with blood groups). All samples were stored in 37⁰C and 100% humidity for 96 hours. The microhardness of the samples was measured with Vickers test.

Results: White MTA samples which have not contaminated with blood had the highest microharness (59.9±11.4 N/mm²) while gray MTA mixed with blood had the lowest hardness (18.45±7.8 N/mm²). One-way ANOVA test showed that contamination with blood significantly reduces the microhardness of both white and gray MTA (p<0.001). The difference between white MTA and gray MTA was significant in groups of no contamination (p<0.001), surface blood contamination (p=0.043), and mixed with blood (p<0.001) according to T-Test analysis. In all of them white MTA had higher hardness than gray MTA.

Conclusion: According to results of our study we recommend that hemorrhage should be controlled and any blood contamination should be removed before placement of both white and gray MTA.

Background and Aims: Dentin contamination with different materials used in pediatrics is effective on the bond strength of adhesives to primary teeth. Therefore, the purpose of this in vitro study was to evaluate the effect of zinc oxide-eugenol and formocresol on the shear bond strength (SBS) of resin composite to the dentin in primary teeth.

Materials and Methods: A total of 72 extracted second morals were selected and mounted in acrylic resin. Buccal and lingual dentin surface were prepared and randomly allocated into 4 groups of 18 specimens each. Groups were subjected to different treatments as follows: group A, the surfaces were received no pretreatment and served as control group B, the surfaces were covered with a paste of ZOE (Zoliran) group C, the surfaces were covered with a paste of ZOE (Kemdent) group D, specimens were placed on gauze soaked in formocresol. The specimens were covered with tinfoil and stored in distilled water at 37oC for 7 days. The temporary restorations were removed after one week. The dentin surfaces were treated with single bond adhesive resin 3M (ESPE/USA) according to manufacturer’s instructions and light cured for 20 seconds. Composite P60 columns (4 mm internal diameter and 3 mm height) were applied on the prepared surfaces and light cured for 40 seconds. Shear bond testing were carried out after 24 hours with a cross head speed of 0.5 mm/min. Statistical analysis was conducted using one- way ANOVA and Tukey Post-hoc test.

Results: The mean shear bond strengths were 17.52±3 MPa for group A, 15.41±3.3 MPa for group B, 15.63±3.2 MPa for group C, and 18.57±3.8 MPa for group D. There was no significant difference between the shear bond strength of group A compared with those of groups B, C, and D (P>0.05).

Conclusion: The bond strength of composite to dentin in primary teeth was not influenced by the zinc-oxide eugenol (Zoliran & Kemdent) or formocreosol.

Background and Aims: Use of glass ionomer cements in pediatric dentistry is increasing and limited information exists with regard to the effect of salivary contamination on the shear bond strength of glass-ionomer to dentin in primary teeth. The aim of this study was to evaluate the effect of salivary contamination on the shear bond strength of two types of glass ionomer cements to dentin in primary teeth.
Materials and Methods: A total of 36 human extracted primary molars were used in this study. The specimens were divided into two groups for each material and then further subdivided into three groups: group 1: uncontaminated, group 2: contaminated with saliva, group 3: contaminated, washed and air dried. The specimens in groups I, II, III were bonded to glass-ionomer and in groups IV, V, VI to resin modified glass-ionomer. Shear bond strength was measured using an Instron machine at 1 mm/min cross head speed. Data were analyzed with ANOVA and Tukey test.
Results: There were significant differences in the mean shear bond strength among groups IV, V (P=0.05). There were no significant difference among groups I & II (P=0.16), I & III (P= 0.93) and IV & VI (P=0.98).
Conclusion: Results showed that salivary contamination can decrease the mean shear bond strength of light- cured glass-ionomer to dentin in primary teeth.