Risk aspects of dental restoratives: From amalgam to tooth-colored materials

Dental materials' choice of patients has considerably changed. Whereas cast gold and amalgam have been the predominant biomaterials for decades, today toothcolored materials like resin-based composites and ceramics are more and more successful. However, are we going to replace a good but biologically questionable material(amalgam) with an equal material(resin composite) being more esthetic but also biologically questionable? For amalgam, long-term clinical studies reported some significant hints that in single cases amalgam may be a health hazard for patients, finally Norway banned amalgam completely. The main advantage of a resin-based composite over amalgam is its tooth-like appearance and more or less absence of extensive preparation rules. For many years it was believed that resin-based composites may cause pulpal injury. However, pulpal injury associated with the use of resin-based composites is not correlated with their cytotoxic properties. Nevertheless, resin-based composites and other dental materials require rigorous safety evaluation and continuous monitoring to prevent adverse events similar like with amalgam. Because of nonbiocompatible pulp responses to resin-based composites and amalgam, they should not be placed in direct contact with the dental pulp. The less dentin remaining in the floor of preparations between resin-based composites or other dental materials is more likely to cause pulpitis. Percentage of patients and dental practitioners who display allergic reactions is between 0.7% and 2%. The release of cytotoxic monomers from resin-based materials is highest after polymerization and much lower after 1 wk. Substances released from resin-based composites have been shown to be toxic in cytotoxicity tests. Nevertheless, in vitro cytotoxicity assays have shown that amalgam has greater toxic effects than resin-based composites, sometime 100-700-fold higher. Altogether, the risk of side-effects is low, but not zero, especially for dental personnel.

Effects of low intensity laser irradiation phototherapy on dental pulp constructs

AIM: To investigate low intensity laser irradiation phototherapy(LILIP) on the proliferation, mineralization and degradation of dental pulp constructs.METHODS: Stem cells from human exfoliated deciduous teeth(SHED) were grown to confluence and seeded on collagen scaffolds to create dental pulp constructs. LILIP was delivered to the dental pulp constructs using an 830 nm GaA IAs laser at an output power of 20 m W. The LILIP energy density was 0.4, 0.8, 1.2, and 2.4 J/cm2. After 8 d, the cell proliferation and degradation within the dental pulp constructs were measured using histologic criteria. After 28 d, the effect of LILIP on SHED mineralization was assessed by von Kossa staining.RESULTS: SHED proliferation within the dental pulp constructs varied after exposure to the 0.4, 0.8, 1.2,and 2.4 J/cm2 LILIP energy densities(P < 0.05). The maximum proliferation of SHED in nutrient deficient media was 218% after exposure to a 1.2 J/cm2 LILIP energy density. SHED grown in nutrient deficient media after exposure to a 0.4, 0.8, and 1.2 J/cm2 LILIP energy density, proliferated by 167-218% compared to the untreated(non-LILIP) control group(P < 0.05).SHED exposed to a 0.4, 0.8, and 1.2 J/cm2 LILIP energy density, and grown in optimal nutritional conditions and proliferated by 147%-164% compared to the untreated(non-LILIP) control group(P < 0.05). The exposure of SHED to the highest LILIP energy density(2.4 J/cm2) caused a reduction of the cell proliferation of up to 73% of the untreated(non-LILIP) control(P < 0.05). The amount of mineral produced by SHED increased over time up to 28 d(P < 0.05). The 0.8 and 1.2J/cm2 LILIP energy densities were the most effective at stimulating the increased the mineralization of the SHED from 150%-700% compared to untreated(nonLILIP) control over 28 d(P < 0.05). The degradation of dental pulp constructs was affected by LILIP(P <0.05). The dental pulp constructs grown in optimal nutritional conditions exposed to a 0.8 J/cm2 or 1.2 J/cm2 LILIP energy density had 13% to 16% more degradation than the untreated(non-LILIP) control groups(P < 0.05). The other LILIP energy densities caused a 1%degradation of dental pulp constructs in optimal nutritional conditions(P > 0.05).CONCLUSION: LILIP can enhance or reduce SHED proliferation, degradation and mineralization within dental pulp constructs. LILIP could promote the healing and regeneration of dental tissues.

Minireview of the clinical efficacy of platelet-rich plasma, platelet-rich fibrin and blood-clot revascularization for the regeneration of immature permanent teeth

The aim of this mini-review was to investigate and compare the clinical efficacy of platelet-rich plasma(PRP) and platelet-rich fibrin(PRF), vs blood clot revascularization(BCR) for the regeneration of immature permanent teeth. The clinical efficacy of PRP, PRF, and BCR to regenerate 90 immature permanent teeth after one year, were compared for their ability to accomplish apical closure, a periapical lesion healing response, root lengthening, and dentinal wall thickening. The 90 cases were published in three different articles. The mean success rate for apical closure after one year was: PRP(89.2%) PRF(80%), and BCR(75.6%). The mean success rate for root lengthening after one year was: BCR(88.9%), PRP(68.2%), and PRF(65%). The periapical lesion healing response was 100% for BCR and 100% for PRP. Dentinal wall thickening was 100% for BCR, and 100% for PRP. All the PRP, PRF, and BCR treatments appeared to be effective. The published clinical results for PRP, PRF, and BCR indicate that these treatments are effective for the regeneration of immature permanent teeth.

What is the purpose of launching the World Journal of Stomatology?

Congratulations to the publisher,members of the editorial board of the journal,all the authors and readers for launching the World Journal of Stomatology(WJS)as a new member of the World series journal family!Significant scientific advances and important breakthroughs need to be published to impact dental care and reach an audience of researchers and clinicians who can create more effective dental treatments for their patients.There is a need to share scientific information,methodologies,therapies,and hypotheses related to stomatology,through an open-access format,to reach the widest possible audience.The WJS was created to fulfill the role of disseminating the most significant,innovative and transformational cutting edge research in dentistry.The WJS is a peer-reviewed open-access periodical centered in stomatology,with a multidisciplinary coverage that will publish high-impact articles in all areas of the dental clinical specialties,applied science,epidemiology,trauma and dental care,dental materials,oral biology and microbiology.The WJS is not scared of controversy or challenges to existing doctrine,since they are supported by high-quality science or unequivocal clinical outcomes.The WJS will avoid publishing confirmatory and low-impact articles.The WJS will only publish articles directly relevant to stomatology and dentistry because this is what our readers expect.If you need to share any exciting dental research discoveries and reach the widest possible audience,you will find in the WJS the most helpful resource to publish your papers!