Is a calcium hydroxide liner necessary in the treatment of deep caries lesions? A systematic review and meta-analysis.

The aim of this systematic review and meta-analysis was to evaluate whether the use of calcium hydroxide (CH) liner improves the clinical success in the treatment of deep caries lesions of primary and permanent teeth. The review was reported in accordance with the PRISMA Statement. Only studies that evaluated deep carious lesions treated with and without a CH liner were included. The required outcomes had to be obtained by clinical, radiographic or laboratory evaluations. Statistical analyses were performed with the RevMan 5.2 program (The Cochrane Collaboration, Copenhagen, Denmark) for randomized clinical trials with at least 12 months of follow-up, using fixed-effect models at a significance level of P < 0.05. The literature search was performed in eight databases: PubMed (MEDLINE), Lilacs, IBECS, BBO, Web of Science, Scopus, SciELO and The Cochrane Library. A total of 17 studies were included (15 in primary teeth, two in permanent teeth). The overall risk difference for CH versus adhesive system in primary teeth was 0.06 [95% CI -0.01 to 0.13], and the overall risk difference for CH versus GIC was 0.10 [95% CI -0.01 to 0.22], with no significant differences between materials. CH liner did not influence the clinical success of treatment for deep caries lesions of primary or permanent teeth. Although the present analysis demonstrated that use of CH liner in deep caries lesions was unnecessary, the evidence was of moderate to very low quality; thus, further well-designed, randomized and controlled clinical trials are necessary to provide stronger recommendations.

Efficacy of antimicrobial agents incorporated in orthodontic bonding systems: a systematic review and meta-analysis.

AIMS: The purpose of this study was to evaluate the efficacy of orthodontic bonding systems containing different antimicrobial agents, as well as the influence of antimicrobial agent incorporation in the bonding properties of these materials. METHODS: Eight databases were searched: PubMed (Medline), Web of Science, Scopus, Lilacs, Ibecs, BBO, Scielo and Google Scholar. Any study that evaluated antimicrobial activity in experimental or commercial orthodontic bonding systems was included. DATA EXTRACTION: Data were tabulated independently and in duplicated by two authors on pre-designed data collection form. DATA SYNTHESIS: The global analysis was carried out using a random-effects model, and pooled-effect estimates were obtained by comparing the standardised mean difference of each antimicrobial orthodontic adhesive with the respective control group. A p-value < .05 was considered as statistically significant. RESULTS: Thirty-two studies were included in the qualitative analysis; of these, 22 studies were included in the meta-analysis. Antimicrobial agents such as silver nanoparticles, benzalkonium chloride, chlorhexidine, triclosan, cetylpyridinium chloride, Galla chinensis extract, acid ursolic, dimethylaminododecyl methacrylate, dimethylaminohexadecyl methacrylate, 2-methacryloyloxyethyl phosphorylcholine, 1,3,5-triacryloylhexahydro-1,3,5-triazine, zinc oxide and titanium oxide have been incorporated into orthodontic bonding systems. The antimicrobial agent incorporation in orthodontic bonding systems showed higher antimicrobial activity than the control group in agar diffusion (overall standardised mean difference: 3.71; 95% CI 2.98 to 4.43) and optical density tests (0.41; 95% CI -0.05 to 0.86) (p < .05). However, for biofilm, the materials did not present antimicrobial activity (6.78; 95% CI 4.78 to 8.77). Regarding bond strength, the global analysis showed antimicrobial orthodontic bonding systems were statistically similar to the control. CONCLUSIONS: Although there is evidence of antibacterial activity from in vitro studies, clinical and long-term studies are still necessary to confirm the effectiveness of antibacterial orthodontic bonding systems in preventing caries disease.

Disclosing the physiology of pulp tissue for vital pulp therapy.

The discovery that dentine is a reservoir of bioactive molecules that can be recruited on demand has attracted efforts to develop new protocols and materials for vital pulp therapy (VPT). The noncollagenous proteins (NCPs) present in the dentine extracellular matrix (ECM) include growth factors (TGF-ß1, BMP-7, FGF-2, IGF-1 and IGF-2, NGF and GDNF), extracellular matrix molecules (DSP, DPP, BSP, DMP-1 and DSPP) and both anti-inflammatory and pro-inflammatory chemokines and cytokines (TNF-α, IL-1, IL-6 and IL-10). Molecules such as DSP and DPP are mainly expressed by odontoblasts, and they are cleaved products from dentine sialophosphoprotein (DSPP). Some molecules, such as TGF-ß1, specifically interact with decorin/biglycan in dentine. Although TGF-ß1 increases the expression and secretion of NGF in human pulp cells, NGF induces mineralization and increases the expression of DSPP and DMP-1. Furthermore, GDNF may act as a cell survival factor and mitogen during tooth injury and repair. Pulp capping materials, such as MTA and calcium hydroxide, can solubilize bioactive dentine molecules (TGF-ß1, NGF and GDNF) that stimulate tertiary dentinogenesis. The binding of these signalling molecules leads to activation of several signalling transduction pathways involved in dentinogenesis, odontoblast differentiation and inflammatory responses, such as the p38 MAPK, NF-kß and Wnt/ß-catenin signalling pathways. Understanding the cascade of cellular and molecular events underlying the repair and regeneration processes provides a reasonable new approach to VPT through a targeted interaction between tooth tissue and bioactive molecules.