Comparing the effects of whey extract and case in phosphopeptide-amorphous calcium phosphate [CPP-ACP] on enamel microhardness

Statement of the Problem: With the recent focus of researches on the development of non-invasive treatment modalities, the non-invasive treatment of early carious lesions by remineralization would bring a major advance in the clinical management of these dental defects. Casein phosphopeptide-amorphous calcium phosphate [CPP-ACP] is considered to be effective in tooth remineralization

Purpose: The aim of this in-vitro study was to compare the effects of whey and CPP-ACP in increasing the enamel microhardness

Materials and Method: Microhardness of 30 sound human permanent premolars was measured before and after 8-minute immersion of samples in Coca-Cola. The teeth were then randomly divided into 3 groups and were immersed in artificial saliva, whey, and tooth mousse for 10 minutes. The changes of microhardness within each group and among the groups were recorded and analyzed using paired t-test

Results: The microhardness increased in each group and between the groups; this increase was statistically significant [p= 0.009]

Conclusion: The effect of whey on increasing the enamel microhardness was more than that of tooth mousse

Cytotoxicity of silver nanoparticles on human gingival epithelial cells: an in vitro study

Objective: Nanosilver has numerous applications in medicine due to its potent antibacterial activity. However, data regarding the bio-safety of its effective concentrations is scarce. This study aims to assess the toxicity of silver nanoparticles on human gingival epithelial cells under in-vitro conditions

Methods: This in vitro study evaluated the toxic effects of filtered and unfiltered nanosilver solution on human gingival epithelial cells obtained from the Pasteur Institute of Iran using the methylthiazol tetrazolium bromide [MTT] assay [mitochondrial function]and membrane leakage of lactate dehydrogenase [LDH] at 24, 48 and 72h time points. The concentrations of silver nanoparticle solution used were 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20 and 50micro g/ml

Results: The MTT assay showed that nanosilver solution at high concentrations [20 and 50micro g/ml] significantly decreased the viability of cells at all time points. The lower non-fatal concentrations at 24 and 48h were capable of causing cell death or significantly inhibit cell growth at 72h. The LDH assay demonstrated that death of epithelial cells only occurs at high concentrations of nanosilver [20 and 50micro g] and no significant toxicity was seen at lower concentrations

Conclusion: Based on the results, silver nanoparticles have toxic effects on human gingival epithelial cells and this effect is time and dose-dependent

Comparison of oral and buccal midazolam for pediatric dental sedation: a randomized, cross-over, clinical trial for efficacy, acceptance and safety

Objective: Providing a safe and efficient dental treatment for a young patient is a challenge for the dentist and the child. The purpose of this study was to investigate the effectiveness, safety and acceptability of buccal midazolam in dental pediatric patients and to compare it with oral Midazolam

Methods: Eighteen uncooperative healthy children aged 2.5-6 years were randomized to each of buccal midazolam [0.3mg/kg] or oral midazolam [0.5mg/kg] at the first visit, the alternative has been used at the second visit in a cross-over manner. The study took place at pediatric dentistry clinic of Shahed University, Tehran, from November 2011 to June 2012. The patients' vital signs and behavioral scores were recorded. The patient, the operator and the observer were blinded to the applied medication. Post operatively, patients' and parents' satisfaction were assessed by Visual Analogue Score and a questionnaire respectively. The P-value was set at 0.05 for significance level

Findings: There were no significant differences in physiologic factors in the medication groups at time 0, 10, 20, 30 minutes and discharge. There was also no significant difference between the two groups in behavioral parameters. The majority of parents rated both sedative agents as "effective" or "very effective" and their children mostly were without anxiety or with minor anxiety

Conclusion: Buccal midazolam may be safely and efficiently used in sedation of pediatric dental patients

[Effect of various amounts of nanosilver incorporation on the mechanical properties of resin modified glass-ionomer cement]

Metallic nano-particles show exclusive biological, chemical and physical characteristic. The purpose of this research was to evaluate the effect of various amounts of nanosilver incorporation [0 [as control], 20, 40, 80, 120, 200 ppm] on the mechanical Properties [compressive and flexural strength] of resin modified Glass ionomer Cement. Based on ISO 4049 and ISO 9971 for polyalkenoid cements, 90 cases in each group were prepared for the flexural and compressive strength. Specimens in 6 groups with different amounts of nanosilver [20, 40, 80, 120 and 200 ppm] and control [Fuji II LC improved], stored in distilled water at 37[degree sign] C for 1 day and 30 days. Flexural strength, using a three-point bending method, Modulus of elasticity and the compressive strength were measured by universal testing machine [Zwick] with crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA and Tukey post HOC test. The flexural strength and modulus of various amounts of nanosilver incorporation of resin modified glass-ionomer cement were not significantly different [P>0.05]. The compressive strength of incorporating of 20 ppm compared with control [P=0.01], 40 ppm [P=0.02] and 80 ppm compared with control [P<0.001] were increased. The flexural strength and compressive strength of Fuji II LC, containing nanosilver particles were increased after 1 day and 1 month significantly [P<0.001]. Incorporation of 20 to 80 ppm nanosilver into Fuji II LC had increased mechanical properties compared to the original cement

histopathological comparison of pulpotomy with sodium hypochlorite and formocresol

Formocresol is widely used in primary teeth pulpotomies; however it is known to have several side effects. The purpose of this study was to assess pulpal changes of primary teeth pulps after pulpotomy with sodium hypochlorite and formocresol. In this randomized clinical trial, 22 teeth were selected. These teeth were randomly divided into 2 groups [formocresol; n=11 and sodium hypochlorite n=11]. Two months post-operatively teeth were extracted and pulpal responses were evaluated by recording the degree of inflammation and extent of pulpal involvement. Dentinal bridge formation was also evaluated. Finally the data was analyzed with McNemartest. The formocresol group demonstrated mild inflammation in 4 cases whereas sodium hypochlorite had mild inflammation in six cases. Severe inflammation was only found in 1 case in the sodium hypochlorite group, but it was present in 4 cases in the formocresol group. In sodium hypochlorite group there were no cases of necrosis, and dentinal bridge was found in 3 cases, unlike, the formocresol group which had necrosis but no dentinal bridge formation. Based on the results of this study sodium hypochlorite may be a suitable solution for conducting pulpotomy in primary teeth

[ effect of various amounts of nanohydroxyapatite on the mechanical properties and remineralization of a fissure sealant]

The main reason for failure in application of fissure sealant is its loss of bond to tooth and development of secondary decays. Nanoparticles of hydroxyapatite have convenient biologic properties and we can try to benefit from these characteristics by adding them to repair materials. The present study was performed with the aim to assess the effect of addition of various amount nanoparticles of hydroxyapatite on mechanical properties such as microshear bond strength and physical properties like curing depth and degree of conversion as well as evaluation of teeth enamel remineralization. In the present laboratory experimental study different weight percentages comprising 0% [control], 1%, 3%, 5%, 10% and 15% of nanoparticles of hydroxyapatite with 50 nm dimensions were separately added to fissure sealant. Then degree of conversion test by Fourier Transform Infrared Spectroscopy [FTIR] and curing depth according to ISO 4049 standard were performed on prepared samples. For the microshearbond strength test 35 premolar teeth without caries were used. The substance properties measurement device [Zwick] was used to do the test. Remineralization of permanent teeth enamel was assessed by Scanning Electron Microscopy [SEM]. Raw data obtained were statistically analyzed by normal distribution test [Kolmogorov-Smirnov], one way ANOVA and Tukey Post Hoc. Results showed that microshear bond strength and degree of conversion had no significant difference in various concentrations of fissure sealant containing hydroxyapatite nanoparticles [P>0/05]. Between microshear bond strength and degree of conversion means of 3M commercial fissure sealant and usual fissure sealant there was no significant difference [P>0/05]. Curing depth in concentrations of 10% [P=0] and 15% [P=0] statistically significantly decreased compared to previous groups [P<0/05]. Curing depth of 3M commercial fissure sealant group was lower compared to conventional fissure sealant group [P=0] and the difference was statistically significant [P<0/05]. A remineralized region on the surface between the fissure sealant and tooth enamel was observed by SEM. This region was more remarkable in higher concentrations. Fissure sealant containing hydroxyapatite nanoparticles with effect on remineralization on the surface of tooth enamel can lead to reduction of micro-leakages and prevention of development of secondary caries while mechanical properties do not decline

Clinical and radiographic success of pulpotomy with MTA in primary molars: 30 months follow up

Pulpotomy of carious primary teeth with an exposed pulp is a common treatment option. Pulpotomy has been conducted with various medicaments over the years. The aim of this study was to evaluate clinical and radiographic success of primary vital pulpotomy with ProRoot and Root MTA. In this randomized clinical trial, children aged between 3-7 years who met the inclusion criteria were enrolled. A total of 70 teeth were deemed suitable under the inclusion criteria and teeth were randomly divided into the 2 groups; ProRoot and Root MTA. Pulpotomy was performed and immediately followed by coronal amalgam restoration. The clinical and radiographic follow ups were conducted 6, 12, 18, 30 months post-operatively. The data were analyzed using Exact Fisher test. At the final follow up, 28 teeth in ProRoot MTA and 26 teeth in Root MTA were evaluated. In the Root MTA group, 1 tooth had exfoliated and one had an abscess and furcal radiolucency radiographically. In ProRoot MTA group, external resorption was observed in 1 tooth. Statistical analysis did not show significant difference in success rate between 2 groups after 30 months. The success rates of Root and ProRoot MTA are similar, indicating that pulpotomy can be carried out successfully in both primary molars