Evaluation of Sealant Penetration in Relation to Fissure Morphology, Enamel Surface Preparation Protocol and Sealing Material.

PURPOSE: The objective was to assess the effect of fissure depth and enamel surface preparation protocols on penetration of resin-based, giomer and glass-ionomer fissure sealants. MATERIALS AND METHODS: Ninety extracted third molars were assigned into three groups according to the material used. All three groups were subsequently divided depending on tooth preparation: no pretreatment or surface preparation with 10% polyacrylic acid, 37% phosphoric acid, or self-etching adhesive. In addition, Er,Cr:YSGG laser or air abrasion were employed in all subgroups. The penetration was evaluated using scanning electron microscopy. RESULTS: The groups that were pretreated with an appropriate acid resulted in superior penetration of glass-ionomer and resin-based sealants when compared with other surface preparation protocols (p < 0.05). The exception was teeth treated with both air abrasion and acid etching. Both preparation protocol and fissure depth significantly affected the sealant penetration (p < 0.05), but fissure depth had a greater impact on fissure penetration than did enamel surface pretreatment. CONCLUSION: All investigated materials exhibit similar properties regarding sealant penetration. Penetration of a fissure sealant is significantly influenced by the fissure depth. In regard to enamel surface preparation protocol, a pretreatment with phosphoric acid in resin-based and polyacrylic acid in glass-ionomers appears to be essential in obtaining the adequate penetration of a sealing material.

Surface characterization of the raw and cooked bovine cortical metatarsal bone.

PURPOSE: The purpose of this study was to quantify the elastic properties and evaluate microscopical features of raw and boiled metatarsal bovine bone. METHODS: The elastic modulus, hardness and microscopic surface of raw and cooked bovine metatarsal bone have been investigated using nanoindentation, SEM/EDX and Panasis microscope. RESULTS: Regarding raw bovine bone, the average elastic modulus was 30.515 ± 6,769 GPa, while the average hardness was 0.5683 ± 0.211 GPa. When it comes to boiled bone corresponding values were 22.298 ± 7.0303 GPa and 0.408 ± 0.199 GPa, respectively. The values for investigated parameters were significantly higher (p < 0.05) in raw bone specimens. Elastic modulus significantly correlated with hardness (p < 0.05). EDX analysis revealed significant decrease in wt% of oxygen in boiled samples (p < 0.05) No significant differences could be observed in SEM images particularly when analysing in smaller magnifications. Using higher magnification, additional branching of the existing voids as well as discrete reorganization and smoother edges of nutrient canals could be observed. The surface of boiled specimens was without the presence of crusts and layering, and no microscopical evidence of structural damage could be observed. CONCLUSIONS: This study provides detailed analysis of hardness, elastic modulus of raw and cooked bovine bone and their relation and changes during exposure to temperature. These results of elastic moduli and hardness could be comparable to similar studies of bovine and human bone tissue, but the careful analysis of experimental design, type of the bone as well as limitations of the employed techniques must be carried out before interpolation of the results to other theoretical, clinical, biomaterial and archeological studies.

Unmet oral health needs among persons with intellectual disability.

The aim of this study was to examine the factors affecting oral health status among intellectually disabled individuals in Serbia. The sample population was categorized according to age, sex, living arrangements, general health and the level of intellectual disability (ID). The diagnosis of dental caries was performed using the DMFT/dmft criteria. The oral hygiene and gingival health were assessed with the plaque index (Silness&Löe) and gingival index (Löe&Silness), respectively. Descriptive analysis, step-wise and logistic regression were performed to analyze related influential factors for caries presence, number of extracted teeth, teeth restored, the oral hygiene level and the extent of gingival inflammation. Odds ratios for caries were significantly higher among adult persons with ID, in persons with co-occurring developmental disorders (DDS) and increased with the level of ID. Group with DDS was associated with a 1.6 times greater odds of untreated decay, while the institutionalization was associated with 2.4 times greater odds of untreated decay. Institutionalization and co-occurring disabilities have been found to be significantly associated with a higher probability of developing gingivitis. Targeting oral health services to individuals with ID are encouraged and may help to reduce overall negative effect on oral and general health associated with delayed treatments, chronic dental pain, emergency dental care, tooth loss and advanced periodontal disease.

Influence of pastes containing casein phosphopeptide-amorphous calcium phosphate on surface of demineralized enamel.

PURPOSE: The purpose of the study was to evaluate the surface characteristics of demineralized enamel after treatment with pastes containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) or casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP) and to compare their efficacy with that of 0.05% NaF. METHODS: Following formation of the artificial carious lesion, enamel slabs were divided into 4 groups (CPP-ACP, CPP-ACFP, 0.05% NaF and control) and submitted to a chemical caries model. Remineralization potential was examined using scanning electron microscope, energy-dispersive spectroscopy (EDS) and microhardness test. Scanning electron microphotographs were analyzed for area, minimal, maximal and mean diameter, perimeter, roundness and number of enamel defects and percentage of tooth surface affected by defects. RESULTS: Treatment with 0.05% NaF partly reduced the appearance of enamel defects when compared with irregular demineralized enamel. Treatment with CPP-ACP or CPP-ACFP resulted in occlusion of defects which produced more flattened enamel surface. Image analysis revealed reduction of the dimensions of the defects in the 3 experimental groups. Treatment with CPP-ACFP decreased the number of enamel defects when compared with demineralized enamel. The EDS analysis did not show differences in Ca/O, P/O and Ca/P ratios between the groups (P>0.05). Microhardness test revealed significant effects of CPP-ACP and CPP-ACFP (P<0.05). CONCLUSIONS: Pastes containing CPP-ACP or CPP-ACFP showed potential to remineralize enamel surface lesions.

Fluoride content and recharge ability of five glassionomer dental materials.

BACKGROUND: The relationship between fluoride content and fluoride release for glass-ionomer cements is not well understood. The aim of this laboratory study was: to determine the fluoride concentrations at the surfaces of glass-ionomer materials with respect to different storage media and different pH environments; to examine the recharge ability of the materials after NaF immersion; and to assess the morphological changes at the material surfaces using scanning electron microscope and energy dispersive spectroscopic techniques (SEM/EDS). METHODS: Five glass-ionomer materials, Fuji Triage (FT), Fuji II LC (FII), Fuji VIII (FVIII), Fuji IX GP (FIX), and Ketac N100 (KN), were analyzed in this study. Resin-based fluoride releasing material Helioseal F (HSF) was used as a comparison material. The sample consisted of 120 cured cement disks (n = 20 disks of each tested material, 10 x 1.5 mm). Five disks of each material were stored in 4 different storage media (I- saline, II- acidic solution ph = 2.5, III- acid solution ph = 5.5, IV- NaF solution (c = 500/106). After 7 days, two disks of each material were transferred from media I, II and III to the NaF solution for 3 min. EDS analysis was conducted in 3 randomly selected spots of each experimental disk. SEM was used to determine morphological characteristics of the material surface. Differences between the experimental groups have been analyzed using Student's t-test with the level of significance set at p < 0.001. RESULTS: FT showed the highest fluoride content at the surface of the material. The lowest amounts of fluoride ions were detected at the surfaces of the FT disks stored at low pH environments, and this difference was statistically significant (p < 0.001). Glass-ionomers showed significantly higher fluoride concentrations when compared to the HSF (p < 0.001). After immersion in the NaF solution, fluoride concentrations at the surfaces of the disks increased when compared with previous storage media (FT>FVIII>KN>FII>FIX). SEM analysis of the surface morphology revealed numerous voids, cracks and microporosities in all experimental groups, except for KN and HSF. More homogenous material structure with more discrete cracks was observed in samples stored at neutral pH environment, compared to disks stored in acidic solutions. CONCLUSION: The tested materials could be considered as promising dental materials with potential prophylactic characteristics due to their relatively high fluoride content, but also the ability to extensively reabsorb fluoride ions, especially in acidic environments.