Immunohistochemical analysis of human homologue of drosophila patched (PTCH) in dental follicles of impacted third molars / Análisis imunohistoquímico del homólogo humano del gen parcheado de drosofila (PTCH) en folículos dentales de terceros molares retenidos

This study investigated the immunodetection of PTCH in epithelial components of dental follicles associated with impacted third molars without radiographic signs of pathosis. One hundred and five specimens of dental follicles associated with impacted third molars with incomplete rhizogenesis (between Nolla's stage 6 and 9) were surgically removed from 56 patients. Epithelial cell proliferation was determined by using immunohistochemical labeling. Statistical analysis was performed using Fisher exact test and a level of significance of 5 percent. Of the 105 dental follicles collected, 3 were PTCH-positive. The specimens with squamous metaplasia and epithelial hyperplasia had higher rates of positivity for PTCH, as well as those with active remnants of odontogenic epithelium. This study suggests that the odontogenic cells of the dental follicle might be proliferating during the rhizogenesis, while the squamous metaplasia and hyperplasia of the epithelial lining and proliferative odontogenic epithelial rests show the differentiation potential of dental follicles.

Se investigó la inmunodetección de PTCH en los componentes epiteliales de los folículos dentales asociados a terceros molares retenidos sin signos radiográficos y morfológicos de patología. Fueron quirúrgicamente extraídos de 56 pacientes 105 muestras de folículos dentales asociadas a terceros molares retenidos con rizogénesis incompleta (entre el estadio de Nolla 6 y 9). La proliferación de células epiteliales se deteminó mediante inmunohistoquímica. El análisis estadístico se realizó mediante la prueba exacta de Fisher. De los 105 folículos dentales recogidos, 3 fueron PTCH-positivos. Las muestras con metaplasia escamosa e hiperplasia epitelial tuvieron mayores tasas de positividad para PTCH, así como aquellos con los restos de proliferación del epitélio odontogénico. En conclusión, este estudio sugiere que las células odontogénicas del folículo dental podrían estar proliferando durante la rizogénesis, mientras que la metaplasia escamosa e hiperplasia del epitelio y de restos epiteliales odontogénicos en proliferación muestran el potencial de diferenciación de los folículos dentales.

Immunohistochemical Analysis of Proliferating Cell Nuclear Antigen (PCNA) in Dental Follicles of Impacted Third Molars / Análisis Imunohistoquímico de Antígeno de Proliferación Celular Nuclear (PCNA) en Folículos Dentales de los Terceros Molares Retenidos

This study investigated the immunodetection of PCNA in epithelial components of dental follicles associated with impacted third molars without radiographical and morphological signs of pathosis. A total of 105 specimens of dental follicles associated with impacted third molars with incomplete rhizogenesis (between Nolla's stage 6 and 9) were surgically removed from 56 patients. Epithelial cell proliferating was determined by using immunohistochemical labeling. Statistical analysis was performed using the Fisher exact test. Of the 105 dental follicles collected, 6 were PCNA-positive ( 6 percent). The specimens with squamous metaplasia and epithelial hyperplasia had higher rates of positivity for PCNA, as well as those with proliferative remnants of odontogenic epithelium. In conclusion, this study shows that dental follicles at this stage of development have low proliferative potential, but suggests that squamous metaplasia, hyperplasia of the epithelial lining and presence of proliferative odontogenic epithelial rests in the connective tissue may be early signs of developing lesions of odontogenic origin.

Se investigó la inmunodetección de PCNA en los componentes epiteliales de los folículos dentales asociados a terceros molares retenidos sin signos radiográficos y morfológicos de la patología. Fueron extraídos quirúrgicamente, de 56 pacientes, 105 muestras de folículos dentales asociados a terceros molares retenidos con rizogénesis incompleta (entre los estadíos de Nolla 6 y 9) La proliferación de células epiteliales se deteminó mediante inmunohistoquímica. El análisis estadístico se realizó mediante la prueba exacta de Fisher. De los 105 folículos dentales recogidos, 6 fueron PCNA-positivos ( 6 por ciento). Las muestras con metaplasia escamosa e hiperplasia epitelial tuvieron mayores tasas de positividad para PCNA, así como aquellos con restos de proliferación del epitelio odontogénico. En conclusión, este estudio mostró que los folículos dentales en esta etapa del desarrollo tienen un potencial proliferativo bajo, pero sugiere que la metaplasia escamosa, la hiperplasia del epitelio y la presencia de restos epiteliales odontogénicos, en proliferación en el tejido conectivo, pueden ser signos tempranos de lesiones en el desarrollo de origen odontogénico.

Hipersensibilidade Dentinária / Dentin Hypersensitivity

A hipersensibilidade dentinária é definida como uma resposta dolorosa curta e aguda, a diferentes estímuos que normalmente não causariam dor em um dente sadio. Possuietiologia multifatorial, porém, se instala principalmente quando a dentina localizada na região cervical do dente fica exposta ao meio bucal. Atualmente, para o tratamento da hipersensibilidade dentinária, são utilizadas substancias que promovem a oclusão dos canalículos dentinários expostos ou que atuam diretamente nas terminações nervosas intrapulpares evitando a despolarização da membrana axonial. Desta forma, o presente trabalho tem por objetivo revisar a literatura sobre o tema com enfoque clínico voltado para a tomada de decisão terapêutica.

The dentin hypersensitivity is defined as a brief and acute pain response to different stimuli that normally would not cause pain in a sound tooth. It has a multifactorial etiology; however, it specially occurs when the dentin at the cervical region of the tooth is exposed to the oral environment. Currently, many substances are being used to promote occlusion of the exposed dentinal canaliculi or that act directly on the intra pulpar nerve endings avoiding depolarization of the membrane axonial. Thus, this study aims to review the literature on the subject and foccus toward clinical decision-making.