Periodontal self‐care: evidence‐based support

The focus of this review on periodontal self‐care will be based primarily on the results of systematic reviews and meta‐analyses. Based on the evidence gleaned from systematic reviews, it is notable that most authors of these reviews commented on the relatively small number of trials that could pass the quality‐assessment inclusion in the systematic review. Interproximal devices, namely interproximal brushes, are more effective for reducing interproximal plaque and gingivitis than are flossing or brushing alone. Some added benefit may be attributed to the use of rotational oscillation powered toothbrushes over manual toothbrushes. Recommendations by the dentist and dental hygienist to add one or more chemotherapeutic agents to the typical oral hygiene regimen has been shown, in systematic reviews and meta‐analyses, to reduce the level of plaque and gingival inflammation in patients. Oral irrigation does not seem to reduce visible plaque but does tend to reduce inflammation, determined by the presence of bleeding on probing, the gingival index score and probing depth measurements. To date, high‐quality evidence is either lacking or weak in some areas regarding the efficacy of self‐care and periodontal disease. Low educational attainment, smoking and socio‐economic status are related to adverse periodontal health outcomes. Variation in self‐esteem, self‐confidence and perfectionism are associated with oral health status and oral health behaviors. Better understanding of the psychological factors associated with oral hygiene would be of benefit in further developing strategies to help patients improve their oral hygiene in addition to helping professionals design better programs on prevention and education.     

Stem cell‐based tooth and periodontal regeneration

Currently regeneration of tooth and periodontal damage still remains great challenge. Stem cell‐based tissue engineering raised novel therapeutic strategies for tooth and periodontal repair. Stem cells for tooth and periodontal regeneration include dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), stem cells from the dental apical papilla (SCAPs), and stem cells from human exfoliated deciduous teeth (SHEDs), dental follicle stem cells (DFSCs), dental epithelial stem cells (DESCs), bone marrow mesenchymal stem cells (BMMSCs), adipose‐derived stem cells (ADSCs), embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). To date, substantial advances have been made in stem cell‐based tooth and periodontal regeneration, including dentin–pulp, whole tooth, bioroot and periodontal regeneration. Translational investigations have been performed such as dental stem cell banking and clinical trials. In this review, we present strategies for stem cell‐based tissue engineering for tooth and periodontal repair, and the translational studies.     

The anti‐caries efficacy of calcium carbonate‐based fluoride toothpastes

Aim : To summarise clinical support for the anti‐caries efficacy of fluoride toothpastes containing sodium monofluorophosphate (SMFP) and to discuss the possible means by which the abrasive particles in calcium carbonate‐based SMFP toothpastes might complement and/or enhance fluoride efficacy. Background : The anti‐caries efficacy of fluoride has been proven beyond any reasonable doubt, and the efficacy of SMFP, when incorporated into a variety of compatible toothpaste formulations, has been established in numerous clinical trials. Calcium carbonate‐based toothpastes may also influence caries by effecting an increase in plaque calcium levels; an inverse relationship between plaque calcium and caries is well‐established. It has also been reported that plaque fluoride levels are dependent on plaque calcium levels. Hence elevated plaque calcium resulting from the use of calcium carbonate‐based toothpastes has the potential to elevate plaque fluoride, itself linked to reduced caries experience. It has been shown that calcium carbonate particles are retained by plaque and this may also influence caries by neutralising harmful plaque acids and concurrently liberating calcium. Conclusion : Fluoride delivered from calcium carbonate‐based SMFP toothpastes is an effective means of reducing caries. Further, calcium carbonate may confer additional benefits through elevation of oral calcium levels and neutralisation of plaque‐acids.     

Fracture resistance of computer‐aided design/computer‐aided manufacturing‐generated composite resin‐based molar crowns

The aim of this study was to investigate whether different fabrication processes, such as the computer‐aided design/computer‐aided manufacturing (CAD/CAM) system or the manual build‐up technique, affect the fracture resistance of composite resin‐based crowns. Lava Ultimate (LU), Estenia C&B (EC&B), and lithium disilicate glass‐ceramic IPS e.max press (EMP) were used. Four types of molar crowns were fabricated: CAD/CAM‐generated composite resin‐based crowns (LU crowns); manually built‐up monolayer composite resin‐based crowns (EC&B‐monolayer crowns); manually built‐up layered composite resin‐based crowns (EC&B‐layered crowns); and EMP crowns. Each type of crown was cemented to dies and the fracture resistance was tested. EC&B‐layered crowns showed significantly lower fracture resistance compared with LU and EMP crowns, although there was no significant difference in flexural strength or fracture toughness between LU and EC&B materials. Micro‐computed tomography and fractographic analysis showed that decreased strength probably resulted from internal voids in the EC&B‐layered crowns introduced by the layering process. There was no significant difference in fracture resistance among LU, EC&B‐monolayer, and EMP crowns. Both types of composite resin‐based crowns showed fracture loads of >2000 N, which is higher than the molar bite force. Therefore, CAD/CAM‐generated crowns, without internal defects, may be applied to molar regions with sufficient fracture resistance.     

The clinical success of tooth‐ and implant‐supported zirconia‐based fixed dental prostheses. A systematic review

The aim was to make an inventory of the current literature on the clinical performance of tooth‐ or implant‐supported zirconia‐based FDPs and analyse and discuss any complications. Electronic databases, PubMed.gov, Cochrane Library and Science Direct, were searched for original studies reporting on the clinical performance of tooth‐ or implant‐supported zirconia‐based FDPs. The electronic search was complemented by manual searches of the bibliographies of all retrieved full‐text articles and reviews, as well as a hand search of the following journals: International Journal of Prosthodontics, Journal of Oral Rehabilitation, International Journal of Oral & Maxillofacial Implants and Clinical Oral Implants Research. The search yielded 4253 titles. Sixty‐eight potentially relevant full‐text articles were retrieved. After applying pre‐established criteria, 27 studies were included. Twenty‐three studies reported on tooth‐supported and 4 on implant‐supported FDPs. Five of the studies were randomised, comparing Y‐TZP‐based restorations with metal–ceramic or other all‐ceramic restorations. Most tooth‐supported FDPs were FDPs of 3–5 units, whereas most implant‐supported FDPs were full arch. The majority of the studies reported on 3‐ to 5‐year follow‐up. Life table analysis revealed cumulative 5‐year survival rates of 93·5% for tooth‐supported and 100% for implant‐supported FDPs. For tooth‐supported FDPs, the most common reasons for failure were veneering material fractures, framework fractures and caries. Cumulative 5‐year complication rates were 27·6% and 30·5% for tooth‐ and implant‐supported FDPs, respectively. The most common complications were veneering material fractures for tooth‐ as well as implant‐supported FDPs. Loss of retention occurred more frequently in FDPs luted with zinc phosphate or glass–ionomer cement compared to those luted with resin cements. The results suggest that the 5‐year survival rate is excellent for implant‐supported zirconia‐based FDPs, despite the incidence of complications, and acceptable for tooth‐supported zirconia‐based FDPs. These results are, however, based on a relatively small number of studies, especially for the implant‐supported FDPs. The vast majority of the studies are not controlled clinical trials and have limited follow‐up. Thus, interpretation of the results should be made with caution. Well‐designed studies with large patient groups and long follow‐up times are needed before general recommendations for the use of zirconia‐based restorations can be provided.