Whole Tooth Regeneration: Can Animal Studies be Translated into Clinical Application?

Tooth loss leads to several oral problems and although a large number of treatments have been proposed to rehabilitate partially or totally edentulous patients, none of them is based on replacement of a missing tooth by a new natural whole tooth. In the field of tissue engineering, some animal models have been developed to regenerate a natural tooth in the oral cavity. This review shows the state of the art in whole tooth regeneration based on data from in vivo studies. A systematic scoping review was conducted to evaluate studies that described whole-tooth regeneration and eruption in the oral cavity. The data demonstrated that over 100 animals were used in experimental studies and all of them received implants of tooth germs constructed by bioengineering processes. Mini pigs and pigs were used in four studies followed by mice (n = 1) and dog (n = 1). Over 58 (44%) animals showed whole tooth eruption around 3.5 months after tooth germ implantation (1 to 13.5 months). Most of specimens revealed the presence of odontoblasts, dentin, dentinal tubules, dental pulp, root analogue, cementum, blood vessels, and alveolar bone. It could be concluded that in vivo whole tooth regeneration was proved to be possible, but the challenge to overcome translational barriers and test these approaches in humans still remains. Impact Statement Advances in tissue engineering have led to the development of new methods to regenerate and replace tissues and organs, including teeth. Tooth regeneration is the main goal for the replacement of tooth loss and therefore current evidence showed that tissue engineering might provide this treatment in future.

Does enamel matrix derivative application provide additional clinical benefits in the treatment of maxillary Miller class I and II gingival recession? A systematic review and meta-analysis.

OBJECTIVE: This review aimed to evaluate the effects of enamel matrix derivative (EMD) in association with coronally advanced flap (CAF) or CAF + connective tissue graft (CTG) when compared with CAF alone or CAF + CTG for the treatment of gingival recessions (GR) in maxillary teeth. METHODS: Five databases and gray literature were searched up to April 2020, to find randomized clinical trials comparing the clinical effects of CAF + EMD versus CAF alone (first group) or CAF + CTG + EMD versus CAF + CTG (second group) in the treatment of Miller class I and II or Cairo type I gingival recessions (GR). Random effects model of mean differences was used to determine the GR reduction, gain in keratinized tissue width (KTW), and gain in clinical attachment level (CAL). The trial sequential analysis (TSA) was implemented to determine the optimal information size (OIS) and imprecision using the GRADE approach. Bayes factors were calculated as complementary statistical evidence of p value. RESULTS: From 1349 titles identified, 9 trials representing 336 GR were included. The meta-analysis showed a statistically significant difference for GR reduction and CAL gain in favor CAF + EMD (p ≤ 0.05). The additional effect of EMD showed a statistically significant difference in GR reduction in favor CAF + CTG + EMD (p ≤ 0.05). The differences in KTW gain proved to be not statistically significant in both comparison groups. The OIS were not met among meta-analyses. Evidence certainty according the GRADE approach proved to be moderate for GR reduction and gain in CAL, but very low for gain in KTW. CONCLUSION: The adjunctive application of EMD in the treatment of GR in maxillary teeth either with CAF or CTG provided moderate certainty evidence in favor of their use for reduction in GR and gain in CAL at 6 and 12 months. However, their effect on the increase in keratinized tissue band height showed very low evidence certainty for its use. CLINICAL RELEVANCE: To know if EMD could improve the results for root coverage.

Inhibición de Streptococcus mutans aislado de cavidad oral de niños sin caries mediante sustancia antagónica producida por Lactobacillus spp / Inibição do Streptococcus mutans isolado da cavidade oral de crianças sem cárie por substância antagônica produzida por Lactobacillus spp / Streptococcus mutans inhibition by antagonistic substance produced by Lactobacillus spp isolated from oral cavity in children without caries

La caries es considerada todavía una de las enfermedades más prevalentes del mundo. Por este motivo, diversas estrategias de prevención se han desarrollado en los últimos años con el propósito de controlar esta enfermedad. Diferentes especies bacterianas de la microbiota normal de la cavidad oral producen sustancias antagónicas antibacterianas. Objetivo: El objetivo de este trabajo fue identificar alguna especie del género Lactobacillus productor de sustancias antagónicas contra Streptococcus mutans a partir de saliva de niños con y sin caries. Materiales y métodos: Se aislaron desde saliva de 60 niños con caries, sin caries activa (rehabilitados) y libres de caries, diferentes cepas de Lactobacillus a las cuales se les estudió su capacidad antagónica contra cepas de Streptococcus mutans , mediante ensayos en doble capa, test del pocillo y sobre crecimiento bacteriano. Resultados: Las cepas que elaboran sustancias con mayor capacidad antagónica fueron identificadas como Lactobacillus fermentum mediante Api test 50 CH. Conclusión: Se demostró que Lactobacillus fermentum está presente en mayor porcentaje en el grupo de niños sin caries, lo cual podría sugerir un efecto natural de control biológico en la cavidad oral de este grupo de niños.

A cárie dentária ainda é considerada uma das doenças mais prevalentes no mundo. Por esta razão, várias estratégias de prevenção foram desenvolvidas nos últimos anos com o objetivo de controlar esta doença. Diferentes espécies bacterianas da microbiota normal da cavidade oral produzem substâncias antagonistas antibacterianas. Objetivo:O objetivo deste estudo foi identificar algumas espécies do gênero Lactobacillus produtoras de substâncias antagonistas contra Streptococcus mutans da saliva de crianças com e sem cárie. Materiais e Métodos: Foram isolados a partir da saliva de 60 crianças com cavidades, sem cavidades ativas (restaurada) e livre de lesões de cárie, diferentes tipos de Lactobacillus que foram estudados pela sua capacidade antagonista contra Streptococcus mutans, por testes camada dupla e bem sobre o crescimento bacteriano. Resultados: As cepas que elaboraram substâncias com maior capacidade antagônica foram identificadas como Lactobacillus fermentum pelo teste Api 50 CH. Conclusões: Foi demonstrado que o Lactobacillus fermentum está presente em maior porcentagem no grupo de crianças sem cárie, o que poderia sugerir um efeito natural do controle biológico na cavidade bucal desse grupo de crianças

Caries is still considered one of the most prevalent diseases worldwide. For this reason, in recent years various prevention strategies have been developed with the purpose of managing this disease. Different oral cavity bacterial species part of the normal microbiota produce antibacterial antagonistic substances. Objective: The objective of this study was to identify some species of Lactobacillus genus that produce antagonistic substances against Streptococcus mutans from saliva of children with and without caries. Materials and methods: Different Lactobacillus strains were isolated from saliva of 60 children with caries, without active decay (rehabilitated) and free of caries. The antagonistic capacity against strains of Streptococcus mutans was studied, by means of tests in double layer, test of the well and about bacterial growth Results: Lactobacillus strains that produced substances with greater antagonistic capacity were identified as Lactobacillus fermentum by Api test 50 CH. Conclusions: It was found that Lactobacillus fermentum is present in a larger percentage among children without caries which could suggest a natural biological control effect by this bacterial strain.