Influence of Dental Pulp Harvesting Method on the Viability and Differentiation Capacity of Adult Dental Pulp-Derived Mesenchymal Stem Cells.

OBJECTIVE: To compare two pulp harvesting methods for stem cell expansion, namely, conservative pulpotomy and pulpectomy from exodontia. METHOD: Ten freshly extracted sound third molars from five patients were selected. Five were used in the control group, where pulp harvesting was performed by exodontia and the remaining teeth were used in the test group, where the pulp was harvested by conservative pulpotomy (preserving the tooth). This was a split-mouth design study, where a third molar from one side was randomly allocated into the test group and the contralateral tooth in the control group. After pulp harvesting, the following evaluations were performed: cell morphology, sterility test, immunophenotyping, differentiation assays, first pass live cell counts, time to cryopreservation, and total number of expanded cells at the end of the fourth pass. RESULTS: Regarding morphology, the cells from both groups presented a fibroblastic phenotype. All samples were sterile. Immunophenotyping demonstrated a positive expression for CD105, CD90, and CD73 and negative expression for CD45 in both groups. Differentiation assays were positive for osteogenic and chondrogenic differentiation in both groups. Regarding live cell counts in the first passage, the control group had 95.8% live cells in the total count and the test group 91.2% (p < 0.05). The time required for cryopreservation was equivalent in both groups 51.6 days and 52.6 days, respectively (p > 0.05). The total number of cells at the end of the fourth passage was 5,286,782 and 5,736,862, respectively (p > 0.05). CONCLUSION: These results suggest that adult stem cell harvesting from conservative pulpotomy is as effective as the traditional exodontia-based method.

Implantes transalveolares imediatos / Transaveolar immediat implants

Os implantes dentários imediatos são, por definição, aqueles instalados no mesmo ato cirúrgico de exodontias dos elementos dentários a serem substituídos pela implantação. Como vantagens desse tipo de técnica, podemos citar: altas taxas de sucesso (aproximadamente 95% dos casos), proporciona a redução de etapas cirúrgicas, com possibilidades reabilitadoras mais rápidas - notadamente em áreas de grande relevância estética - além de, com um sítio dentário ainda residente, -alvéolo dentário com a morfologia muito próxima da original - permitir reestruturar características teciduais muito próximas das presentes quando na dentição natural. Por outro lado, outros fatores sugerem uma análise inicial bem criteriosa, podendo, por vezes, limitar ou mesmo contra-indicar a aplicação da técnica de implantação imediata : a qualidade e quantidade óssea da região a ser implantada, a qual incidirá diretamente sobre a presença ou ausência de estabilidade primária do implante, a necessidade de cirurgia periodontal prévia, ou mesmo a morfologia residual do alvéolo dentário, que, dependendo do formato da raiz (raízes com lacerações, alvéolos com septos, entre outros)limitará o posicionamento adequado do implante

The immediate implants are, as definition, those that are positioned in the course of surgical extraction of the tooth to be replaced. The advantages of this technique are: high success rates of implantation procedures (approximately 95% of the cases), ashortening of treatment time (without a second surgical procedure), besides, the preservation of the extraction socket walls (required for implant installation) permitting maintaining tecidual aspects to a morphology pretty close to the original form. However, there are another factors that suggest a criterious initial analysis that can determine the indication or the contraindication of the technique: the bone quality and quantity (direct factors of influence in the primary stability), the necessity of a previous periodontal approach, or even the extraction socket morphology, which root anatomy can limit a ideal positioning of the implant