Review of nanomaterials in dentistry: interactions with the oral microenvironment, clinical applications, hazards, and benefits.

Interest in the use of engineered nanomaterials (ENMs) as either nanomedicines or dental materials/devices in clinical dentistry is growing. This review aims to detail the ultrafine structure, chemical composition, and reactivity of dental tissues in the context of interactions with ENMs, including the saliva, pellicle layer, and oral biofilm; then describes the applications of ENMs in dentistry in context with beneficial clinical outcomes versus potential risks. The flow rate and quality of saliva are likely to influence the behavior of ENMs in the oral cavity, but how the protein corona formed on the ENMs will alter bioavailability, or interact with the structure and proteins of the pellicle layer, as well as microbes in the biofilm, remains unclear. The tooth enamel is a dense crystalline structure that is likely to act as a barrier to ENM penetration, but underlying dentinal tubules are not. Consequently, ENMs may be used to strengthen dentine or regenerate pulp tissue. ENMs have dental applications as antibacterials for infection control, as nanofillers to improve the mechanical and bioactive properties of restoration materials, and as novel coatings on dental implants. Dentifrices and some related personal care products are already available for oral health applications. Overall, the clinical benefits generally outweigh the hazards of using ENMs in the oral cavity, and the latter should not prevent the responsible innovation of nanotechnology in dentistry. However, the clinical safety regulations for dental materials have not been specifically updated for ENMs, and some guidance on occupational health for practitioners is also needed. Knowledge gaps for future research include the formation of protein corona in the oral cavity, ENM diffusion through clinically relevant biofilms, and mechanistic investigations on how ENMs strengthen the tooth structure

Nanocharacterization in Dentistry

About 80% of US adults have some form of dental disease. There are a variety of new dental products available, ranging from implants to oral hygiene products that rely on nanoscale properties. Here, the application of AFM (Atomic Force Microscopy) and optical interferometry to a range of dentistry issues, including characterization of dental enamel, oral bacteria, biofilms and the role of surface proteins in biochemical and nanomechanical properties of bacterial adhesins, is reviewed. We also include studies of new products blocking dentine tubules to alleviate hypersensitivity; antimicrobial effects of mouthwash and characterizing nanoparticle coated dental implants. An outlook on future “nanodentistry” developments such as saliva exosomes based diagnostics, designing biocompatible, antimicrobial dental implants and personalized dental healthcare is presented

Early colonization of dental implants by putative periodontal pathogens in partially edentulous patients

There is limited scientific information available on the early colonization of the peri-implant pockets in partially edentulous individuals. Knowledge about this process is one step in better understanding the etiology and pathogenesis of peri-implantitis. In this study, the early colonization of the peri-implant pockets by putative periodontal pathogens was studied in 20 partially edentulous individuals using anaerobic culture techniques. At baseline, the presence and levels of putative periodontal pathogens in the microflora of periodontal pockets and saliva were established. Immediately after loading of the titanium implants and after 6 and 12 months the presence and levels of selected putative periodontal pathogens were determined in periodontal and peri-implant pockets. A second aim was to detect bacterial contamination of the implant site and the inside of the implant. At baseline, the most frequently isolated species from the periodontal pockets were Fusobacterium nucleatum, Prevotella intermedia and Peptostreptococcus micros. Bacteroides forsythus, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were isolated from 9, 2 and 3 patients respectively. Six months after placing of the bridges, the majority of the implant sites had detectable levels of most periodontal bacterial species with the exception of A. actinomycetemcomitans which could not be isolated from any of the peri-implant samples during the experimental period, although 2 patients had this organism at baseline. In 2 patients with detectable subgingival P. gingivalis at baseline this species was found after 12 months in the peri-implant sites. One of these patients lost 2 implants which was associated with a high proportion of P. gingivalis in the peri-implant pockets. A second patient developed 2 fistulas around 2 implants at 8 months and this event was also associated with the presence of P. gingivalis. It is concluded that proper periodontal infection control before instalment of dental implants in partially edentulous patients may prevent early bacterial complications

Immediate implant placement and provisionalisation in the aesthetic zone

The aim of this retrospective study was to assess the outcome of immediate single-tooth implant placement and provisionalisation in the aesthetic zone regarding hard and soft peri-implant tissue parameters and patient-related outcome measures in a private practice. All consecutively treated patients with single-tooth immediate implant placement and provisionalisation between the period 1 January 2006 and 1 April 2013 in a referral practice in Amsterdam, the Netherlands, were included in the study. Fifty-one patients of a total of 64 could be examined at follow-up (Tfollow-up). Radiographs were present from implant placement (T-placement), after definitive crown placement (T-definitive), and new radiographs were taken at the follow-up appointment (Tfollow-up). Next to this, soft tissue parameters, patients' satisfaction and professionals' aesthetic scores were measured at Tfollow-up. Implant survival was 969% after a mean follow-up period of 4 years following implant placement. At definitive crown placement, mean marginal bone-level loss was 025 mm (SD 019). Mean marginal bone-level loss following definitive crown placement was 006 mm (SD 010) (T-definitive to Tfollow-up) after a mean follow-up period of 4 years. Plaque index, bleeding index and gingival index scores were low. Patients' satisfaction was rated very high: 90 (SD 07). Professionals aesthetic score was 1649 (SD 186). From this study can be concluded that immediate placement of implants followed by immediate provisionalisation resulted in a high survival rate, minimum peri-implant bone loss, very good aesthetics and satisfied patients after a mean follow-up period of 4 years