Should deciduous teeth be preserved in adult patients? How about stem cells? Is it reasonable to preserve them?

Abstract When seeking orthodontic treatment, many adolescents and adult patients present with deciduous teeth. Naturally, deciduous teeth will inevitably undergo exfoliation at the expected time or at a later time. Apoptosis is the biological trigger of root resorption. In adult patients, deciduous teeth should not be preserved, as they promote: infraocclusion, traumatic occlusion, occlusal trauma, diastemata and size as well as morphology discrepancy malocclusion. Orthodontic movement speeds root resorption up, and so do restoring or recontouring deciduous teeth in order to establish esthetics and function. Deciduous teeth cells are dying as a result of apoptosis, and their regeneration potential, which allows them to act as stem cells, is limited. On the contrary, adult teeth cells have a greater proliferative potential. All kinds of stem cell therapies are laboratory investigative non authorized trials.

Resumo Muitos adolescentes e adultos, ao procurar pelo tratamento ortodôntico, apresentam dentes decíduos persistentes. Naturalmente, os dentes decíduos ou se esfoliam na época esperada ou mais tardiamente, de forma inevitável. A apoptose é o gatilho biológico da rizólise. Em adultos, os dentes decíduos não devem ser preservados, pois promovem: infraoclusão, oclusão traumática, trauma oclusal, além de diastemas e má oclusão por discrepância de tamanho e morfologia. O movimento ortodôntico acelera o processo de rizólise, assim como restaurar ou reanatomizar dentes decíduos para inseri-los em uma estética e função. As células dos dentes decíduos estão morrendo por apoptose e seu potencial regenerativo para atuarem como células-tronco tem limitações, ao contrário das células de dentes adultos, que têm maior potencial proliferativo. Todas as terapias com células-tronco ainda são laboratoriais e se enquadram como ensaios investigativos não autorizados.

Fracture strength of flared bovine roots restored with different intraradicular posts

OBJECTIVE: The aim of this study was to evaluate the fracture strength and failure mode of flared bovine roots restored with different intraradicular posts. MATERIAL AND METHODS: Fifty bovine incisors with similar dimensions were selected and their roots were flared until 1.0 mm of dentin wall remained. Next, the roots were allocated into five groups (n=10): GI- cast metal post-and-core; GII- fiber posts plus accessory fiber posts; GIII- direct anatomic post; GIV- indirect anatomic post and GV- control (specimens without intraradicular post). A polyether impression material was used to simulate the periodontal ligament. After periodontal ligament simulation, the specimens were subjected to a compressive load at a crosshead speed of 0.5 mm/min in a servo-hydraulic testing machine (MTS 810) applied at 135¨¬ to the long axis of the tooth until failure. The data (N) were subjected to ANOVA and Tukey's post-hoc test (¥á=0.05). RESULTS: GI and GIV presented higher fracture strength (p<0.05) than GII. GIII presented intermediate values without statistically significant differences (p>0.05) from GI, GII and GIV. Control specimens (GV) produced the lowest fracture strength mean values (p<0.05). Despite obtaining the highest mean value, GI presented 100 percent of unfavorable failures. GII presented 20 percent of unfavorable failures. GIII, GIV and GV presented only favorable failures. CONCLUSIONS: Although further in vitro and in vivo studies are necessary, the results of this study showed that the use of direct and indirect anatomic posts in flared roots could be an alternative to cast metal post-and-core.

Complete denture impression techniques: evidence-based or philosophical.

Code of practice is dangerous and ever-changing in today's world. Relating this to complete denture impression technique, we have been provided with a set of philosophies--"no pressure, minimal pressure, definite pressure and selective pressure". The objectives and principles of impression-making have been clearly defined. Do you think any philosophy can satisfy any operator to work on these principles and achieve these objectives? These philosophies take into consideration only the tissue part and not the complete basal seat, which comprises the periphery, the tissues and the bone structure. Under such circumstances, should we consider a code of practice dangerous or should we develop an evidence-based approach having a scientific background following certain principles, providing the flexibility to adapt to clinical procedures and to normal biological variations in patients rather than the rigidity imposed by strict laws?

Enamel matrix derivative in periodontal reconstructive surgery. A new approach in periodontal regeneration.

True periodontal regeneration is the goal of any periodontal regenerative techniques. Cementum formation is a key event in the development of root and supporting periodontium. Due to its distribution, acellular cementum is the type most affected by early to moderate periodontitis. Studies over the past twenty years demonstrated that, enamel matrix proteins from the root sheath are involved in the formation of acellular, during tooth development. Thus the adjunctive use of enamel matrix derivatives in conjunction with regenerative periodontal surgery could possibly lead to true periodontal regeneration. The purpose of this article is to review the use of enamel matrix derivative in true periodontal regeneration.

Etiología de las enfermedades periimplantarias / Etiology or periimplant diseases

Se han reconocido factores etiológicos y asépticos. Se ha establecido similitud entre la etiología y avance de la patología periodontal y periimplantar. Existe similitud entre la microflora asociada de los implantes defectuosos y los organismos asociados a enfermedad periodontal. Deben lograrse niveles de salud periodontal y asegurarse el control de placa por parte del paciente antes de colocar implantes dentales. Es evidente que los problemas infecciosos o protéticos deben ser reconocidos tempranamente, para permitir la intervención antes que se pierda una parte sustancial de hueso de soporte. Son claras las desventajas que ocasiona la ausencia del ligamento periodontal. Una reabsorción ósea periimplantar de aproximadamente 1,5mm. luego del priemer año, es esperada y considerada normal

Movilidad dentaria: su importancia clínica / Tooth mobility: its clinical relevance

Las estructuras de soporte del diente responden mediante diversos mecanismos adaptativos a la fuerza que recibe el diente. Así, ante una fueza axial unidireccional, el dinte cambia de posición y los tejidos vuelven luego a la normalidad, ante una fuerza de vaivén los cambios dar n como resultado final un aumento del ancho del ligamento periodontal y un aumento de la movilidad progresiva ("adaptación"). Cuando la acción de las fuerzas se combina con la enfermedad periodontal inflamatoria activa, puede ocurrir que si queda poco tejido de inserción el ligamento periodontal no pueda adaptarse a las fuerzas oclusales y aparecer entonces una movilidad progresiva que puede determinar la pérdida del diente

Consideraciones periodontales en el diseño de prótesis parciales removibles. Parte 1 / Periodontal considerations in the design of removable partial dentures. Part 1

Se presenta una revisión de la literatura referente a la prótesis parcial removible sobre los tejidos periodontales y las consideraciones en el diseño de cad uno de los elementos constituyentes. Se concluye que el control de la placa y los programas de mantenimiento son los factores fundamentales para la conservación de los tejidos remanentes, objetivo principal de toda restauración protésica; en tal sentido, también es importante considerar el control de la cobertura del tejido periodontal por alguna parte de la P.P.R. y la fuerza oculsal transmitida a las estructuras de soporte

Movilidad dentaria: su importancia clínica / Tooth mobility: its clinical relevance

Las estructuras de soporte del diente responden mediante diversos mecanismos adaptativos a la fuerza que recibe el diente. Así, ante una fuerza axial unidireccional, el diente cambia de posición y los tejidos vuelven luego a la normalidad; ante una fuerza de vaivén, los cambios darán como resultado final un aumento del ancho del ligamento periodontal y un aumento de la movilidad no progresiva ("adaptación"). Cuando la acción de las fuerzas se combina con la enfermedad periodontal inflamatoria activa, puede ocurrir que si queda poco tejido de inserción, el ligamento periodontal no pueda adaptarse a las fuerzas oclusales y aparecer entonces una movilidad progresiva que puede determinar la pérdida del diente

Processo de reparo em dentes com rizogênese incompleta após traumatismo e/ou tratamento endodôntico: artigo de revisäo / Process of repairing in incompletely developed teeth after traumatic injury and endodontic therapy: article review

Diferentes formas de complementaçäo apical têm sido observadas em dentes com história de traumatismo e/ou tratamento endodôntico. Os mecanismos envolvidos no processo de reparo obedecem fatores determinantes, destacando-se a importância da preservaçäo das estruturas periapicais, do remanescente pulpar, da ausência de infecçäo e da terapia endodôntica aplicada

La periodoncia, la ortodoncia y su relación recíproca en tratamiento de pacientes adultos / Periodontics, orthodontics and their reciprocal relationship in the treatment of adult patients

La enfermedad dental puede dividirse dentro de dos categorías: caries dental y enfermedad periodontal. Ambas enfermedades deberán ser tratadas antes de iniciar un tratamiento ortodóntico. El tratamiento de la caries es regularmente hecho dentro de la rutina dental, al contrario de la enfermedad periodontal que no es diagnosticada ni tratada en sus inicios tempranos. En este artículo se propone discutir o mencionar algunas formas de la enfermedad periodontal y la existencia de ésta así como su tratamiento y su influencia sobre el tratamiento ortodóntico