IN-VITRO EFFECTS OF AN ACIDIC BY-PRODUCT FEED ON BOVINE TEETH

Objective-To evaluate in vitro erosive effects of sweet potato cannery waste (SPCW) on bovine incisor enamel. Sample Population-20 bovine ma ndibles. Procedure-Mandibles were collected and incisors were classifi ed into 3 categories: lacking observable wear, advanced normal wear, o r abnormal wear associated with feeding SPCW. Intact mandibles were ra diographed. Contralateral normal teeth from the same jaw were used to compare Ca2+ loss (etching) with SPCW, lactic acid (pH 3.2), or SPCW n eutralized with NaOH to pH 5.0 or 5.5. Scanning electron microscopy wa s performed to compare etched and unetched specimens. Two abnormally w orn teeth were evaluated histologically. Knoop hardness testing was co nducted on unexposed areas of surface enamel and enamel exposed to SPC W. Results-Radiography revealed large periapical abscesses in the mand ibles exposed to SPCW. Nearly identical amounts of Ca2+ were removed b y SPCW and lactic acid solution at the same pH. Scanning electron micr oscopy did not indicate consistent differences between etch patterns r esulting from exposure to SPCW or lactic acid. Mean rate of calcium re moval was 56% higher in deciduous than permanent teeth. Knoop hardness data suggested that softening occurred in enamel exposed to SPCW. Neu tralizing SPCW to pH 5.5 eliminated calcium removal. Histologic examin ation of sections indicated that SPCW degraded and removed some dentin matrix proteins. Conclusions- Exposure to SPCW results in enamel eros ion in vitro; low pH is the most likely cause of erosion. Neutralizing SPCW to pH 5.5 eliminated erosive effects. Clinical Relevance-Confirm ation of SPCW's erosive effects on enamel in vitro supported the field diagnosis.