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Effect of exposure to the carcinogen 50 ppm 4-nitroquinoline 1-oxide on alveolar bone loss
Marcelo Ekman Ribas1, Tobias Rauber Spuldaro1, Harry Juan Rivera Oballe2
1Department of Periodontology, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Background:
The objective of this study was to analyze the effect of exposure to the carcinogen 4-nitroquinoline 1-oxide (4NQO), with or without experimental periodontitis (EP), on alveolar bone loss (ABL) in rats.
Materials And Methods:
Male Wistar rats (n = 84) were divided into Group 1: no EP and no exposure to 4NQO; Group 2: exposure to 4NQO (50 ppm) only; Group 3: EP only; and Group 4: after 20 weeks of exposure to 4NQO (50 ppm), EP was induced by placing a silk ligature on the upper right maxillary second molar for 15 days. Macroscopic analysis of the tongue and morphometric analysis of ABL were performed. Kruskal-Wallis and Mann-Whitney U tests were used, and a significance level of P < 0.05 was adopted.
Results:
All animals exposed to 4NQO presented macroscopic lesions on the tongue. When considering the side with EP, no statistically significant difference was demonstrated between Groups 3 (median: 0.76; intervals interquartile [IQ]: 0.42-0.45) and 4 (median: 0.78; IQ: 0.70-0.80). In the side without EP, Group 4 (median: 0.51 mm; IQ: 0.45-0.70) presented significantly higher ABL compared to Group 1 (median: 0.41 mm; IQ: 0.38-0.43). Group 3 (median: 0.44; IQ: 0.41-0.47) showed no significant difference when compared to Groups 1 (median: 0.41; IQ: 0.38-0.43) and 2 (median: 0.46; IQ: 0.41-0.54).
Conclusions:
It was concluded that higher ABL occurred in the presence of a carcinogen. However, the combination of both 4NQO and EP did not promote higher ABL.
