English

Abstract

Introduction Photodynamic antimicrobial chemotherapy studies regarding dental caries have been present more frequently in the literature. However, photodynamic antimicrobial chemotherapy depends on the adjustment of variables such as the type of light source and, photosensitisers target microorganism; this makes it difficult to draw meaningful comparisons. The purpose of this paper was to provide a critical review related to this coadjuvant approach in the prevention and treatment of dental caries. Materials and Methods A database search was made via Medline/PubMed (keywords: photodynamic therapy and dental caries) and 33 articles were found. Results Twelve articles were included after using the filter tool, being excluded reviews and manuscripts reporting works not related to the studied area. Conclusion The manuscripts showed that photodynamic therapy presents optimal results against dental caries, even though better understanding of photodynamic antimicrobial chemotherapy and its components are necessary before the clinical application of this alternative modality in the dental practice. Photodynamic antimicrobial chemotherapy for prevention and treatment of dental caries: a critical review MA Paschoal1, S Duarte2*, L Santos-Pinto1* Introduction The human oral cavity is heavily colonised by a complex, relatively specific and highly interrelated range of microorganisms (as many as 1000 different species have been detected) collectively known as normal oral microflora1. A peculiarity of this environment is that most of the bacteria found here are present in complex aggregates (known as biofilms)2. Microbial biofilms are composed of microorganisms adhered both to each other and to dental surfaces (or interfaces) and embedded in an extracellular polymeric matrix, which includes water and nutrient channels3. A change in a key environmental factor will trigger a shift in the balance of the resident microflora, which will promote the emergence of acidogenic/aciduric bacteria. The constant accumulation of these kind of bacteria change the equilibrium towards dental demineralisation (dental caries lesions)4. The constituents of diet present an important role in the development of dental caries. Sucrose is considered the most cariogenic dietary carbohydrate, because it is fermentable and serves as a substrate for the synthesis of extracellular polysaccharides (EPS) and intracellular polysaccharides in cariogenic dental plaque4. In addition, the presence of EPS (mainly insoluble glucan) promote bacterial adherence to the tooth surface and contribute to the structural integrity of dental biofilms. Yet, there is a clear evidence showing that sucrose exposure and insoluble EPS lead to a more cariogenic biofilm5. Dental caries is among the most significant human chronicle infectious diseases and results in the progressive dissolution of enamel. With the disease progression, it can lead the underlying dentine compromising the vitality of the element and its fixation in the maxillomandibular complex6. Prevention of dental caries can be achieved by controlling the accumulation of dental plaque by mechanical removal7. In cases of insufficient biofilm disorganisation, the association with antimicrobial chemical agents, such as chlorhexidine may help in the decreasing of pathogenic bacteria levels7. Unfortunately, this preventive approach does not reach the population as a whole, allowing dental cavity formation. Treatment of the carious lesion involves the removal of infected dentine with posterior restoration of the affected tooth with any of the variety of materials, for example mercury amalgam, resin composite and glass ionomer cements8. Due to emergence of antibiotic resistant strains, alteration in taste, burning sensation, increase of calculus formation and staining of the teeth and restorative materials stimulated a search for alternative treatments9. Recently, approaches that might offer the possibility of efficient intraoral bacterial count reduction with minimum damage to systemic health (preventive approach) and avoid secondary caries development reducing the chance of material substitution and pulp inflammation as well (curative approach) are necessary. For these circumstances, photodynamic antimicrobial chemotherapy (PACT) offers the possibility of a novel modality to reduce pathogenic bacteria, and consequently, prevent against (new) dental caries lesions10. * Corresponding authors Emails: marcobpaschoal@hotmail.com; lspinto@foar.unesp.br; sd84@nyu.edu 1 Department of Pediatric Dentistry, Araraquara School of Dentistry, Univ Estadual Paulista (UNESP), Araraquara, SP, Brazil 2 Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University (NYU), New York, NY, USA