Histological comparison of DBBM and platelet rich fibrin for guided bone regeneration in a rabbit model.

PURPOSE: To histologically evaluate the use of bovine derived deproteinized xenograft (DBBM), leukocyte and platelet rich fibrin (L-PRF) and the combination of both in Guided Bone Regeneration (GBR) performed in non-critical size defects in rabbit. METHODS: A prospective experimental study was performed. Four bone defects in the tibiae of 12 rabbits were made and each of them was filled with DBBM, L-PRF, a combination of DBBM + L-PRF or was left to heal as control site. All defects were covered with a collagen membrane. Rabbits were randomly distributed in three groups and euthanatized at 3, 6 or 9 weeks. Samples were obtained and histologically analyzed to determine vital bone, connective tissue and remaining graft particles percentage. Analysis of variance, Kruskal Wallis and non-paired t-test where used to evaluate the significance of the results. RESULTS: At 3 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p = 0,05) and DBBM + L-PRF showed significantly less connective tissue than control (p < 0,05). All other groups showed no statistical difference between them. At 6 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p < 0,05), DBBM + L-PRF (p < 0,05) and control (p < 0,05) and there wasn't any other significant difference regarding to connective tissue or remaining particle percentage between groups. At t 9 weeks healing period, there weren't any significant differences between groups. CONCLUSIONS: DBBM seems to enhance vital bone formation at early healing stages. The use of L-PRF alone or combined with DBBM, didn't show any histological improvement regarding to vital bone formation. The use of DBBM, alone or in conjunction with L-PRF showed a trend to reduce connective tissue percentage. The use of L-PRF combined with DBBM didn't affect the remaining particle percentage.

Preservación de alvéolos mediante fosfato tricálcico beta, con y sin membrana / Socket preservation using beta-tricalcium phosphate with or without membrane

El presente estudio evalúa los resultados de la utilización del fosfato tricálcico beta en la preservación de alvéolos postextracción al emplearlo solo o en conjunto con membranas no reabsorbibles. Se seleccionaron 18 dientes con indicación de extracción y con condiciones favorables para la preservación del alvéolo y posterior colocación de un implante oseointegrado. En 10 alvéolos se utilizó como relleno fosfato tricálcico beta en conjunto con membrana no reabsorbible, y 8 alvéolos fueron tratados solamente con fosfato tricálcico beta. Previo a la cirugía se evaluó el ancho y alto de cada alvéolo, mediante una tomografía computarizada de alta resolución, evaluación que fue repetida 6 meses después de realizada la intervención quirúrgica. Al momento de efectuar la técnica quirúrgica para la instalación de los implantes se tomaron muestras histológicas del sitio de colocación del implante para estudiar las características histológicas del sitio injertado después de 6 meses de realizada la cirugía de extracción dentaria y preservación de alvéolo. El uso de fosfato tricálcico beta, independiente o no del uso de membrana, mantuvo la altura del alvéolo transcurridos 6 meses desde su colocación, mientras que el ancho del alvéolo se mantuvo solo en el grupo sin membrana. Los resultados histológicos demostraron cantidades variables de regeneración ósea.

The present study evaluated the results of the post-extraction socket preservation technique using Beta-Tricalcium Phosphate with and without the use of a non-resorbable membrane. A total of 18 teeth with indication of extraction and socket preservation were selected, with 10 alveoli being treated with Beta-Tricalcium Phosphate combined with a non-resorbable membrane, and the other 8 with Beta-Tricalcium Phosphate only. The width and height of each socket was evaluated using computed tomography, prior to the extraction, and 6 months after the surgery. At the time of performing the surgical technique for installing the implants, histological specimens were taken from the implant site in order to study the graft site 6 months after the dental extraction surgery and alveoli preservation.The use of Beta-Tricalcium Phosphate, whether a membrane is used or not, maintained the alveolar height 6 months after the extraction, while the width of the alveolus only remained in the group without membrane. Histological results showed varying amounts of bone regeneration.

Parámetros mucogingivales y dentarios en estudiantes de odontología chilenos / Mucogingival and dental parameters in Chilean dental students

Fueron analizados los parámetros de proporción dentaria, posición del cénit gingival, posición y tamaño de las papilas interdentarias, biotipo gingival, cantidad de encía queratinizada y línea de la sonrisa en las 6 piezas anterosuperiores en 31 estudiantes de odontología chilenos. Se estableció un patrón de proporción dentaria similar al descrito previamente en la literatura. La posición de cénit presentó un patrón definido. El biotipo gingival fino fue el más frecuente. Los incisivos laterales presentaron la mayor cantidad de encía queratinizada, seguidos por los incisivos centrales y luego los caninos. La altura de la papila a nivel de los caninos fue mayor que en los incisivos centrales, mientras que los valores más bajos fueron encontrados a nivel de los incisivos laterales. Existió una predominancia de la línea de la sonrisa media.

Tooth proportion, gingival zenith position, position and size of the interdental papillae, gingival biotype, amount of keratinized gingiva and smile line position were evaluated in the 6 upper front teeth in 31 Chilean dental students. The tooth proportion pattern was similar to that described previously in the literature. The zenith position showed an established pattern. A thin gingival biotype was found more frequently. Lateral incisors showed the highest amount of keratinized tissue, followed by central incisors and then the canines. The height of the papillae at the canines was higher than central incisors, while the lowest values were found in the lateral incisors. There was a predominance of a medium smile line.