Regenerative endodontic procedures (REPs) aim at recreating dental pulp tissue using biomaterials such as hydrogels. Their bioactivity is mostly related to the nature of biomolecules or chemical compounds that compose the endodontic hydrogel. However, many other parameters, such as hydrogel concentration, bioactive molecules solubility, and apex size, were reported to influence the reciprocal host–biomaterial relationship and hydrogel behavior. The lack of knowledge regarding these various parameters, which should be considered, leads to the inability to predict the clinical outcome and suggests that the biological activity of endodontic hydrogel is impossible to anticipate and could hinder the bench-to-bedside transition. We describe, in this review, that most of these parameters could be identified, described, and studied. A second part of the review lists some challenges and perspectives, including development of future mathematical models that are able to explain, and eventually predict, the bioactivity of endodontic hydrogel used in a clinical setting.

The aim of the present survey is to investigate the use of antibiotics during periodontal therapy among French dentists with a focus on exploring potential differences between various groups of practitioners. A self-administered questionnaire was distributed to different groups of practitioners including members of (i) the French Society of Periodontology and Implantology; (ii) the College of University Teachers in Periodontology and, (iii) private practitioners participating in the French general dental practice-based research network. 272 questionnaires were included in the analysis. Prescription patterns were globally in line with the current recommendations. Systemic antibiotics are most frequently used as a first-line therapy in necrotizing periodontitis (92%) and aggressive periodontitis (53.3% to 66.1%). However, malpractice still exists, including in the management of periodontal abscesses. Antibiotics are prescribed (i) less frequently for periodontal abscesses and (ii) more frequently for generalized aggressive periodontitis by members of the periodontal society and University college (p < 0.05). Amoxicillin (59.9%) and the amoxicillin + metronidazole (59.6%) combination were the most frequently prescribed molecules. Providing a high number of periodontal treatments per week, being more recently graduated, having a post-graduate certificate in periodontology and holding or having held an academic position/hospital practice were all factors associated with a better knowledge of and/or more adequate antibiotic use.

The aim of our study was to explore the potential value of metallic (Ag, Cu, and Zn) salts, polymer/metallic nanoparticles, and chlorhexidine (CHX) for improving the antimicrobial activity of calcium hydroxide (CH) against E. faecalis and C. albicans, associated with persistent endodontic infections. A first screening was performed by determining minimum inhibitory/bactericidal concentrations (MIC/MBC). Antimicrobial activity of the CH paste mixed with metallic salts, chitosan or cyclodextrin polymer metallic nanoparticles was compared to the antimicrobial activity of CH paste alone and CH + CHX using a time-kill kinetics assay. The effect of the antimicrobials on the rheological and the key mechanical properties were also examined. Copper and zinc were discarded because of their MIC/MBC values and silver because of its kill time curve profile. Except for a slower setting time after 24 h and a higher weight loss after 1 week of incubation, the mechanical behavior of the CH paste was unaffected by the addition of CHX. Polymeric/metallic nanoparticles failed to potentiate the antimicrobial effect of CH. By contrast, CHX increased this effect and thus could help eradicate E. faecalis associated with persistent root canal infections without altering the desired key physical properties of the CH paste.

Regenerative endodontic procedures (REPs) aim at recreating dental pulp tissue using biomaterials such as hydrogels. Their bioactivity is mostly linked to the nature of biomolecules or chemical compounds that will compose the endodontic hydrogel. However, many other parameters, such as hydrogel concentration, type, bioactive molecules solubility, of apex size were reported to influence the hydrogel behavior, leading to the inability to predict the clinical outcome. This lack of knowledge and the various parameters that should be considered, suggest that biological activity of endodontic hydrogel is impossible to anticipate and could hinder the bench to bedside transition. We formulated in this article our opinion that most of these parameters could be identified, described, and studied. A second part of the document lists some challenges and perspectives, including development of future mathematical models able to explain and predict the bioactivity of these endodontic hydrogel in clinic.

Les lésions endo-parodontales (LEP) sont des situations cliniques complexes où coexistent, au niveau d'une même dent, une pathologie parodontale et une pathologie pulpaire. Leur traitement implique en général une approche combinée endodontique et parodontal et leur pronostic est souvent incertain. Les médications intracanalaires (MIC) à base d'hydroxyde de calcium (Ca[OH]2), pour compléter la désinfection canalaire, auraient un effet positif sur la cicatrisation parodontale dans les LEP mais les mécanismes qui expliquent cet effet sont encore mal compris.La première partie de cette étude expérimentale est consacrée à l'optimisation d'une MIC à base de Ca(OH)2 par addition de différents agents antimicrobiens (cuivre, zinc, argent et chlorhexidine [CHX]) et à la caractérisation détaillée des formulations obtenues. Parmi les molécules testés, seule la chlorhexidine (CHX) (0,5%, 1% et 2%) a significativement amélioré, in vitro, l'activité antimicrobienne de la pâte de Ca(OH)2 sur les microorganismes cibles, sans en altérer les propriétés mécaniques et physico chimiques.La deuxième partie du travail rapporte l'étude ex vivo du potentiel de diffusion de composés actifs contenus dans la MIC à travers la racine dentaire et l'étude in vitro de l'effet d'extraits de MIC sur la viabilité et la réponse de trois populations de cellules parodontales (fibroblastes du ligament alvéolo-dentaire, cémentoblastes et ostéoblastes). Une diffusion d'ions (Ca2+, OH-) et de CHX, plus importante via l'apex, a pu être mise en évidence, avec des profils de libération variables au cours du temps et selon la dose de CHX de départ. In vitro, les extraits de Ca(OH)2 dilués (avec ou sans CHX) semblent bien tolérées par les cellules parodontales et réduire la production de médiateurs inflammatoires sans effet significatif cependant sur le potentiel de minéralisation des cellules.