Marginal integrity of aesthetic restorations following intracoronal bleaching with sweet potato extract as an additive: An SEM study

Is Cention-N comparable to other direct dental restorative materials? A systematic review with network meta-analysis of in vitro studies

OBJECTIVES

To compare the performance of Cention-N® with direct restorative materials used at the daily practice (e.g., resin-based composites/RBC, glass ionomer cements/GIC, bioactive resins, silver amalgam) via a systematic review study.

METHODS

The review followed the PRISMA-NMA recommendations, and the protocol of the review was published at osf.io/ybde8. The search was conducted in PubMed/MEDLINE, Scopus, Web of Science, Embase, Lilacs, and SciELO databases, as well as in the grey literature (Open Grey, Proquest, and Periódicos CAPES). Studies with an in vitro experimental design evaluating the characteristics and properties of Cention-N in comparison to other restorative materials were included. The risk of bias of included studies was assessed using the RoBDEMAT tool, and meta-analyses were conducted using Review Manager 5.4 and MetaInsight V3 tools.

RESULTS

A total of 85 studies were included in the review, from which 79 were meta-analyzed. Several characteristics of direct restorative materials were analyzed, including physical (color change, degree of conversion, hardness, microleakage, polymerization rate, roughness, water solubility, water sorption), mechanical (bond strength to dentin, compressive strength, diametral tensile strength, flexural modulus, flexural strength, load-to-fracture, wear), and biological (alkalinizing effect, antibacterial activity, calcium and fluoride release) properties.

SIGNIFICANCE

Cention-N presented similar physico-mechanical properties compared to RBCs, but a stronger behavior than GICs. Despite the Alkasite nature of Cention-N, GICs may still demonstrate the greatest fluoride releasing ability from all direct restorative materials. This review confirmed the adequate behavior of Cention-N when compared to several other more traditionally used materials, confirming its applicability for the permanent restoration of decayed or fractured teeth.

A review on natural teeth whitening

BACKGROUND

Discoloration of teeth occurs for various reasons. Common ingredients like substances from tea and coffee, as well as antibiotics like tetracycline, or food dyes, can percolate into the teeth, and, as such, these stains may persist in the porous structure of the enamel. Smoking is also contributory to dental discoloration, with toxins of tobacco smoke accumulating in a similar way. With aging, teeth tend to be discolored with accumulation of various stains in addition to the enamel gradually eroding to expose the yellow dentin.

HIGHLIGHT

This review focused on the effect of several natural ingredients with teeth-whitening properties and their daily clinical application. Metabolic dental bleaching mechanisms, as well as tooth discoloration and decay, were also reviewed. The current scientific literature (mostly from 2000 to 2020) was consolidated from manuscripts retrieved from Scopus, PubMed, ResearchGate, and Google Scholar.

CONCLUSION

Natural teeth whitening effectively lightens the natural color of teeth without eroding dental surfaces. On the other hand, commercially available whiteners containing hydrogen peroxide and carbamide peroxide, in high concentrations, can lead to deproteinization and demineralization of teeth through oxidation processes. If used extensively, these compounds may cause a number of adverse effects. Alternative natural teeth-whiteners include ingredients like lemons, strawberries, oranges, papaya, and other fruits. Such natural ingredients offer a milder and safer way of whitening teeth than whiteners containing hydrogen peroxide or carbamide peroxide.

Use of antioxidants to restore bond strength after tooth bleaching with peroxides

This review compiles the literature on the antioxidants used after tooth bleaching with either low or high-concentrated carbamide and hydrogen peroxide to recover the bond strength. Antioxidants used in bleached teeth are mainly natural and non-enzymatic, except for catalase. Commonly, antioxidants are applied to remove any reactive oxygen species (ROS) residues left from bleaching gels, which adversely affect adhesive procedures, such as restorations or orthodontic brackets bonding. Even though sodium ascorbate, the most thoroughly investigated antioxidant, showed the most efficient bond strength recovery at 10% concentration, its performance depends on the type of solution and the application time. Natural extracts, such as proanthocyanidins and green tea, showed satisfactory results in the reversal of bond strength at 5% and 10% concentrations, respectively. Sodium ascorbyl phosphate, α-tocopherol, and catalase exhibited promising results, but further research is required. The adhesive system type plays an important role in the outcome of enamel bond strength after the antioxidant application. The postponement of either restorations or orthodontic brackets cementation following bleaching procedures seems to be efficiently replaced by antioxidant application prior to bonding procedures. However, the efficacy of using an antioxidant to recover bond strength depends on its type and application time.