Do Dental X-Rays Induce Genotoxicity and Cytotoxicity in Oral Mucosa Cells? A Critical Review.

Dental X-rays are widely used in clinical practice, since the technique is an important approach for diagnosing diseases in dental and periodontal tissues. However, it is widely known that radiation is capable of causing damage to cellular systems, such as genotoxicity or cytotoxicity. Thus, the aim of this review was to present a critical analysis regarding the studies published on genotoxicity and cytotoxicity induced by dental X-rays in oral mucosa cells. Such studies have revealed that some oral cell types are more sensitive than others following exposure to dental X-rays. Certainly, this review will contribute to a better understanding of this matter as well as to highlighting perspectives for further studies. Ultimately, such data will promote better safety for both patients and dental professionals.

Genotoxicity Induced by Dental Materials: A Comprehensive Review.

Genotoxicity is the capacity of an agent to produce damage in the DNA molecule. Considering the strong evidence for a relationship between genetic damage and carcinogenesis, evaluation of genotoxicity induced by dental materials is necessary for elucidating the true health risks to patients and professionals. The purpose of this article was to provide a comprehensive review of genotoxicity induced by dental materials. All published data showed some evidence of genotoxicity, especially related to dental bleaching, restorative materials and endodontic compounds. Certainly, such information will be added to that already established for regulatory purposes as a safe way to promote oral healthcare and prevent oral carcinogenesis.

Effect of an alcoholic diet on dental caries and on Streptococcus of the mutans group. Study in rats.

The objective of this study was to evaluate the effects of an alcohol diet on Streptococcus of the mutans group and on dental caries in the oral cavity of rats. Forty animals were divided into 3 groups according to the following liquid diets: 20% ethanol solution (Alcohol Group, AG), 27% sucrose solution (Isocaloric Group, IG), and water (Control Group, CG). After 56 days, samples were collected and plated on Mitis Salivarius Bacitracin agar to assess the number of colony forming units (CFU/mL) of Streptococcus of the mutans group. The animals were sacrificed and the jaws were removed in order to assess the occurrence of dental caries on the smooth and occlusal surfaces using stereomicroscopy. The data were submitted to ANOVA and Tukey test. The average numbers of CFU/mL (10(3)) were: 8.17 (AG), 9.78 (IG), and 5.63 (CG). There was no significant difference among the groups for the occurrence of occlusal caries. Regarding smooth surface caries, in the upper jaw, the caries number in the IG (1.58) was similar to that in the AG (2.06) and in the CG (1.14), and the number of caries in the AG was higher than in the CG; in the lower jaw there was significant difference among the 3 groups: AG (1.14), IG (2.00) and CG (0.43). The diets with the alcohol and sucrose solutions presented a tendency of increasing the colonization by Streptococcus of the mutans group and of increasing the occurrence of smooth surface dental caries in rat molars when compared to the control diet.

Effect of an alcoholic diet on dental caries and on Streptococcus of the mutans group: study in rats

The objective of this study was to evaluate the effects of an alcohol diet on Streptococcus of the mutans group and on dental caries in the oral cavity of rats. Forty animals were divided into 3 groups according to the following liquid diets: 20 percent ethanol solution (Alcohol Group, AG), 27 percent sucrose solution (Isocaloric Group, IG), and water (Control Group, CG). After 56 days, samples were collected and plated on Mitis Salivarius Bacitracin agar to assess the number of colony forming units (CFU/mL) of Streptococcus of the mutans group. The animals were sacrificed and the jaws were removed in order to assess the occurrence of dental caries on the smooth and occlusal surfaces using stereomicroscopy. The data were submitted to ANOVA and Tukey test. The average numbers of CFU/mL (10³) were: 8.17 (AG), 9.78 (IG), and 5.63 (CG). There was no significant difference among the groups for the occurrence of occlusal caries. Regarding smooth surface caries, in the upper jaw, the caries number in the IG (1.58) was similar to that in the AG (2.06) and in the CG (1.14), and the number of caries in the AG was higher than in the CG; in the lower jaw there was significant difference among the 3 groups: AG (1.14), IG (2.00) and CG (0.43). The diets with the alcohol and sucrose solutions presented a tendency of increasing the colonization by Streptococcus of the mutans group and of increasing the occurrence of smooth surface dental caries in rat molars when compared to the control diet.

O presente estudo avaliou o efeito de uma dieta alcoólica sobre estreptococos do grupo mutans e sobre cárie dentária na cavidade bucal de ratos. Quarenta animais foram divididos em 3 grupos conforme a dieta líquida administrada: solução de etanol a 20 por cento (Grupo álcool, GA), solução de sacarose a 27 por cento (Grupo isocalórico, GI) e água (Grupo controle, GC). Após 56 dias, amostras bucais foram coletadas e semeadas em ágar Mitis Salivarius Bacitracina para contagem de unidades formadoras de colônias (UFC/mL) de estreptococos do grupo mutans. Os animais foram sacrificados, maxila e mandíbula foram removidas para analisar a ocorrência de cárie nas faces livres e oclusais usando lupa estereoscópica. Os dados foram submetidos à ANOVA e ao teste de Tukey. As médias dos números de UFC/mL (10³) foram: 8,17 (GA), 9,78 (GI), e 5,63 (GC). Não houve diferença significativa entre os grupos para a ocorrência de cárie oclusal. Em relação ao número de cáries em face livre, na maxila este número no GI (1,58) foi similar ao encontrado no GA (2,06) e no GC (1,14), e o número de cáries no GA foi maior do que no GC; na mandíbula houve diferença significante entre os três grupos: GA (1,14), GI (2,00) e GC (0,43). A dieta com soluções de álcool e sacarose apresentou tendência de aumento na colonização de estreptococos do grupo mutans e aumentou a incidência de lesões de cárie de faces livres nos molares de ratos quando comparada à dieta controle.

The role of metronidazole on the establishment and persistence of oral candidosis

The aim of this study was to study the effects of metronidazole on the establishment of oral candidosis and Candida albicans colonization in the oral cavity of rats. Forty-eight male rats, negative for yeasts in the oral cavity, were used in the study. The rats were inoculated with a suspension of Candida albicans and treated with metronidazole or plain water (control group). The rats of the candidosis experimental group were sacrificed 7, 15, or 30 days after inoculation and their tongues were analyzed by light microscopy. Colonization by Candida albicans was evaluated 1, 2, 5 and 7 days after inoculation and progressively at 15-day intervals, with a total of 18 collections. The results demonstrated the development of candidosis on the tongue dorsum was similar between the Control and Metronidazole groups for each sacrifice period. However, the colonization results showed that yeasts were recovered in the Metronidazole group in greater numbers than in the Control group after the 37th day of the experiment (6th collection). According this, the long term metronidazole therapy favored the colonization of C. albicans in the oral cavity of rats.