The Effect of Restoration Polymerization and Residual Dentine Thickness on Thermal Changes of Pulp Chamber of Immature Permanent Teeth

ABSTRACT Objective: To evaluate the pulpal temperature changes due to the polymerisation of resin and glass ionomer-based materials in dentine thicknesses in immature permanent teeth with open apices. Material and Methods: Forty extracted sound human third molar teeth with open apices were included. The width of the cavities prepared on the occlusal surface was 4×5 mm. The depth was 2 mm in the resin groups. 4 mm in the groups in which glass ionomer liner was applied before composite restoration. The coronal parts of the samples were then placed on an acrylic plate with three gaps for feeding-extraction needles and the thermocouple. The temperature changes were recorded. The data was analyzed by SPSS. Statistical significance was accepted as p<0.05. Results: The temperature increase in the group of 1 mm remaining dentin thickness revealed higher results than the values detected from the 2 mm group (1.01 °C) (p=0.00). The mean values (1.49 °C, 1mm) of temperature changes in only glass ionomer applied group were lower than the avarage values (2.210°C, 1mm) determined in the polymerization process of resin composites with light-emitting diode devices. Conclusion: In a remaining dentin thickness of 1 mm in teeth with open apices, using a glass ionomer liner might be a useful effort for protecting the pulp from the heat generated by polymerisation devices.

Investigation of SOSTDC1 gene in non-syndromic patients with supernumerary teeth

BACKGROUND: The etiology of supernumerary teeth is still unclear however heredity is believed to be a major factor and this idea was supported by several case reports. Recently, a relationship between supernumerary tooth formation and deficiency of Uterine Sensitization Associated Gene-1 (Usag-1), a rat gene that is expressed in sensitized endometrium, was reported in mice. The human homolog gene for Usag-1, Sclerostin Domain Containing 1 (SOS-TDC1), shows 85% identity with mouse Usag-1. The present study aimed to investigate SOSTDC1 coding regions in non-syndromic patients with one or more supernumerary teeth. MATERIAL AND METHODS: Twenty-five non-syndromic patients (21 male and 4 female) aged 5-15 years, with one or more supernumerary teeth were included in the study. Saliva samples were collected from patients and DNA samples were isolated and analyzed using PCR. RESULTS: Eight phenotypes of supernumerary tooth formation were observed in the study. From the DNA analysis, 2 novel and 3 previously identified sequence alterations were identified however, in investigating the Usag-1 homolog SOSTDC1 gene, the present study could not find any phenotype-genotype relationship. CONCLUSIONS: There are many SOSTDC1 homolog genes in the human genome and future studies should investigate these candidate genes. Also studies in larger case groups including family members may reveal the hereditary pattern

Micro-computed tomographic analysis of progression of artificial enamel lesions in primary and permanent teeth after resin infiltration.

We investigated inhibition of lesion progression in artificial enamel lesions. Lesions were created on primary and permanent anterior teeth (n = 10 each) and were divided randomly into two groups with two windows: Group 1 (window A: resin infiltration; window B: negative control) and Group 2 (window A: resin infiltration + fluoride varnish; window B: fluoride varnish). After pH cycling, micro-computed tomography was used to analyze progression of lesion depth and changes in mineral density. Resin infiltration and resin infiltration + fluoride varnish significantly inhibited progression of lesion depth in primary teeth (P < 0.05). Inhibition of lesion depth progression in permanent teeth was significantly greater after treatment with resin infiltration + fluoride varnish than in the negative control (P < 0.05). Change in mineral density was smaller in the resin infiltration and resin infiltration + fluoride varnish groups; however, the difference was not significant for either group (P > 0.05). Resin infiltration is a promising method of inhibiting progression of caries lesions.

Clinical evaluation of desensitizing treatment for incisor teeth affected by molar-incisor hypomineralization.

BACKGROUND: Sensitivity complaints are commonly observed in teeth affected by MIH (molar incisor hypomineralization). AIM: This study aimed to evaluate the hypersensitivity observed in MIH-affected teeth and the effect of desensitizing agents applied with and without ozone to incisors affected by MIH. STUDY DESIGN: The first part of the study included 120 teeth from 42 patients with MIH. These 42 patients included 33 children with 92 incisor teeth with a Vas score of > or = 30, and these 92 incisors were included in the second part of the study. The patients included in the second part were divided into three main groups and six subgroups. The main groups included the following: fluoride, CPP-ACP and CPP-ACP with fluoride. Each main group was divided into two subgroups: one with ozone use and one without ozone use. RESULTS: Girls exhibited significantly more sensitivity compared with boys (p < 0.05). There were significant decreases in hypersensitivity compared to baseline in all of the groups (p < 0.05). There were no differences among the groups at the end of the study (p > 0.05). CONCLUSION: The results of this study revealed that gender is an important factor in the sensitivity of teeth with MLH. Desensitizing agents effectively reduced the hypersensitivity of teeth with MIH. CPP-ACP paste was found to be more effective, and ozone therapy prolonged the effect of CPP-ACP paste.

Prevalence of oral abnormalities in a Turkish newborn population.

OBJECTIVE: There are a few studies that describe the oral findings in newborn children in various populations but none conducted for a Turkish population. Hence, this study determined the prevalence of intraoral findings in a group of newborns and examined the correlation among these findings with the mother's systemic and gestational medical complications, cigarette consumption during pregnancy and consanguinity between the parents. METHODS: 2,021 full-term, newborn children were examined. Oral cysts, ankyloglossia, attached upper midline frenum and other medical diagnoses at birth were investigated. Medical information for each child and parent was recorded via standard questionnaire. Obtained data was analysed using the Pearson Chi-Square test (P≤0.05). RESULTS: The most common findings were of oral inclusion cysts situated palatally. CONCLUSIONS: There was a statistically significant relationship between the presence of oral inclusion cysts with the congenital diabetes and also insulin treatment and cigarette consumption during pregnancy. Moreover, a significant relationship was found between the presence of oral inclusion cysts and gestational diabetes and with the presence of consanguinity between the parents (P=0.004).

Adhesion to primary and permanent dentin and a simple model approach.

OBJECTIVES: First to compare different dentin bonding agents' shear bond strength to primary and permanent dentin. Secondly to compare the fracture failure modes and making an attempt to develop a statistical model that could be helpful in predicting them. METHODS: Extracted human primary and permanent molars were used as substrates (dentin). The shear bond strength of composite to substrate was measured and fracture surfaces were evaluated visually and with stereomicroscope. Using the data obtained, a statistical model was built in order to predict the failure modes. RESULTS: Higher bond strength values were obtained for permanent dentin. Total-etch adhesives displayed higher shear bond strength values than the self-etch adhesive. Adhesive failures were more frequently seen in primary dentin. Self-etch adhesive system displayed more adhesive failures. Prepared model confirmed the negative relationship between shear bond strength and the probability of observing adhesive failure. CONCLUSIONS: There should be an application protocol for the usage of dentin bonding agents in primary dentin. Further development of statistical and fuzzy models for failure modes can be supportive alternatives for microscopic evaluations and also be helpful in understanding and eliminating the factors which are responsible for the formation of adhesive failures and for achieving clinically more successful adhesive restorations.