REMINERALIZING EFFECT OF TRICALCIUM PHOSPHATE ON CARIES-LIKE LESION IN ENAMEL OF PRIMARY TEETH (IN VITRO STUDY)

INTRODUCTION Non-invasive management using remineralizing agents is the modern therapeutic approach of non-cavitated lesions (1). The study aimed to evaluate the remineralizing effect of tricalcium phosphate (TCP), silver diamine fluoride (SDF) and sodium fluoride (NaF) varnishes in carious enamel lesions in primary teeth. The null hypothesis was that there would be no significant difference in the mineral content and topographic structure of artificial initial carious primary enamel lesions between the three varnishes. METHODOLOGY Forty-eight primary teeth with standardized windows (4x4 mm.) were immersed in a demineralizing solution for 4 days to initiate caries like lesions on their enamel surface. They were washed with deionized water and kept in artificial saliva. They were divided randomly into four groups of 12 teeth each and were treated according to manufacturer’s instructions with the following varnishes: group I: ClinproTM White varnish (TCP), group II: e-SDF (SDF), group III: Profluorid varnish (NaF) and group IV: no treatment. The varnishes were removed using a cotton swab saturated with acetone. Teeth were washed and stored in artificial saliva for 24 h. They were subjected to pH cycles over a period of ten days. Teeth were immersed daily in demineralizing solution for 6 h. Then, they were immersed in remineralizing solution for 18 h. They were washed thoroughly with deionized water and prepared for assessment. Teeth were evaluated quantitatively using energy dispersive X-ray spectrometer (EDX) and qualitatively using scanning electron microscope (SEM). RESULTS AND DISCUSSION The quantitative analysis (EDX) of the Ca, P level , and Ca/p ratio of this study revealed that after remineralization, the group I showed the highest mean percent change of Ca level (8.56 ± 8.64) then group II (16.09 ±13.41), group III(-16.49 ± 15.91) and group IV (23.38 ± 15.39) with statistically significant difference between the study groups (P<0.0001). The highest mean percent change of P level was significantly highest in group I (7.67 ± 6.50) followed by group III (-12.93 ± 17.77), group IV (-13.03 ± 19.21) and group II (-14.85 ±15.61) with a statistically significant difference between them (P<0.0001). The mean percent change of Ca/p ratio of group I and II is significantly higher than group IV with no significant difference with group III, Table (1). SEM confirmed EDX results. Scanning electron microscopic examination of tricalcium phosphate varnish showing uniform re-establishment of surface integrity of enamel. A decrease in the porosities and surface irregularities was an important feature in this group. Table (1): Comparison of Ca, P content and Ca/p ratio between the study groups