Evaluation of dentin features in teeth after caries removal by three techniques (chemomechanical, mechanical with a smart bur, and air-abrasion): an in vitro study.

Background: Different methods for removing dental carious lesions exist, including conventional rotary caries removal and new advanced technology like polymer-based burs, chemomechanical agents, air abrasion, and laser. Objectives: This study shows the differences in features of dentin (smear layer, patency of dentinal tubules, surface irregularities, intertubular micro porosities, and exposed dentinal tubules) among different types of caries removal techniques. Materials and Methods: An in vitro study was done on 60 primary molars with occlusal class I active caries. Teeth were divided into three groups according to a method of caries removal (G1: chemomechanical, G2: mechanical with a smart bur, and G3: air-abrasion). After complete caries excavation, the teeth were examined under a scanning electronic microscope (SEM) with the power of magnification 4,000x and 8,000x to show the morphological dentinal features with SEM microphotographs. Data obtained was analyzed using the SPSS program where Fisher exact, Kruskal-Wallis and multiple Wilcoxon sum rank tests were used. The level of significance is when the p-value is less than 0.05. Results: Generally, SEM showed the highest ratio of score 1 of smear layer presence, surface irregularities, and microporosity in all groups in both magnifications. The patency of tubules showed the highest ratio of score 1 in G1, scores 2 in both G2 and G3 in magnification 4,000x, while 8,000x there was the highest ratio of its score 1 in G1 and G2 while the G3 has score 2 as the highest score. The exposed dentinal tubules showed the highest ratio in G1 in score 3, in G2 in score 2, and in G3 in score 1 in magnification 4,000x, while 8,000x there was the highest ratio of its score 2 in both G1 and G3 while the G3 has highest score 1. The study with magnification 4,000x showed a significant difference (S) among three groups in exposed dentinal tubules with a p-value (0.012), and there was S between chemomechanical and smart, chemomechanical and air-abrasions groups with a p-value (0.041, 0.001 subsequentially). Other dentin features showed non-significant differences (NS) among or between groups in both magnifications (4,000x, 8,000x). Conclusions: All groups were effective in removing caries and can successfully treat young, scared or stressed patients. All methods of caries removal produce clinically parametric changes in the residual dentin.

Comparison of Some Salivary Characteristics in Iraqi Children with Early Childhood Caries (ECC) and Children without Early Childhood Caries.

BACKGROUND: Early Childhood Caries (ECC) is a unique form of caries that develops in temporary dentition. It has a multifactorial infectious disease. Saliva is one of the most important factors, which has an important protective effect against tooth decay when its multiple characteristics and functions are normal. The study aimed to compare some salivary characteristics in children with ECC and children without ECC. MATERIALS AND METHODS: Case-control, cross-sectional observational study. The 77 pre-schoolers aged 37 to 72 months (12 with ECC, 26 with ECC-S, and 39 without ECC) examined and we collected the stimulated saliva. The pH microelectrode was used to determine pH and buffer capacity; a formula that involves volume, collection time, and specific saliva weight was used to test the salivary flow rate. The potentiometric and phosphate methods were used to determine fluoride through spectrophotometric, colorimetric absorption techniques. RESULTS: The results got to show that there are no statistically significant differences in pH, buffer capacity, salivary flow rate, and levels of fluoride and phosphate, in children with ECC, ECC-S, and without ECC. The risk factors, such as mother's education, bottle use, brushing frequency, and previous dental care of the child are more important at the time of developing ECC than some salivary variables. CONCLUSION: The risk factors, such as mother's education, bottle use, brushing frequency, and previous dental care of the child are more important at the time of developing ECC than some salivary variables such as pH, buffer capacity, salivary flow rate, and levels of fluoride and phosphate.