Effects of Amoxicillin on the Structure and Mineralization of Dental Enamel and Dentin in Wistar Rats

Abstract

Objectives: The development of teeth is affected by genetic and environmental factors. Amoxicillin is a widely prescribed semi-synthetic antibiotic. Its most frequent side effects are gastrointestinal disorders and hypersensitivity reactions. The purpose of this study was to determine the effect produced by amoxicillin administration on dental enamel and dentin in Wistar rats.

Materials and methods: Twelve pregnant adult Wistar rats were equally divided into four different groups. Negative controls were prescribed with a saline solution. Positive controls were prescribed with tetracycline (130 mg/kg). The other two groups were treated with amoxicillin doses of 50 and 100 mg/kg (every 8 hours), respectively. The treatments were daily administered by oral gavage from the 13th gestation day to the end of gestation. After birth, the offspring also received the same treatment as their mothers from day one to day twelve. After 24 hours, the newborns were sacrificed, the jaws were dissected, and the first molar teeth were collected. The samples were fixed in 10% formaldehyde solution and were histomorphologically and histopathologically observed to determine enamel and dentin abnormalities.

Results: The mean ameloblastic layer thickness, enamel thickness, odontoblastic layer thickness, and dentin thickness were significantly different in the tetracycline group and the amoxicillin 50 and 100 mg/kg groups compared to the control group. Also, dentin hypomineralization and vacuolization of the odontoblastic layer were observed in the tetracycline- and amoxicillin-treated groups.

Conclusion: This study showed that amoxicillin interferes with amelogenesis and dentinogenesis and reduces enamel and dentin thickness.

Keywords: Amoxicillin; Dental Enamel; Dentin; Hypomineralization; Wistar Rats.

Fig. 1:

(a) Frontal photomicrography of a tooth from the negative control group; AL=Ameloblastic Layer, E=Enamel, D=Dentin, P=Predentin, OL=Odontoblastic Layer, DP=Dental Pulp; hematoxylin and eosin (H&E) staining; ×200 magnification. (b) Frontal photomicrography of a tooth from the tetracycline group; AL=Ameloblastic Layer, E=Enamel, D=Dentin, P=Predentin, OL=Odontoblastic Layer, DP=Dental Pulp; H&E staining; ×200 magnification. (c) Frontal photomicrography of a tooth from the amoxicillin 50 mg/kg group; AL=Ameloblastic Layer, E=Enamel, D=Dentin, P=Predentin, OL=Odontoblastic Layer, DP=Dental Pulp, *Hypomineralization; H&E staining; ×200 magnification. Disorder (the presence of several vacuoles) is clearly evident, especially in the odontoblastic layer. (d) Frontal photomicrography of a tooth from the amoxicillin 100 mg/kg group; AL=Ameloblastic Layer, E=Enamel, D=Dentin, P=Predentin, OL=Odontoblastic Layer, DP=Dental Pulp, *Hypomineralization; H&E staining; ×200 magnification. Disorder (the presence of several vacuoles) is clearly evident, especially in the odontoblastic layer

Fig. 2:

The error bar of mean and standard errors of (A) ameloblastic layer thickness, (B) enamel thickness, (C) odontoblastic layer thickness, and (D) dentin thickness in the rat neonates. Negative control group (control), positive control group (Tetracycline group, Tetra), amoxicillin 50 mg/kg group (Amoxi50), and amoxicillin 100 mg/kg group (Amoxi100). * P<0.05, ** P<0.01, and *** P<0.001 compared to the control group. All data are presented as Mean±Standard Error (SE).