2nd IADR APR meeting
August 21, 2013
Title: Adopting Minimum Intervention Dentistry: the role of scientific evidence
Room: Crystal I
Prof. David Manton
Dr. Christina Sim (NDC)
Prof. SuchitPoolthong (Chulalongkorn University)
Prof. Baek-II Kim (Yonsei University)
Dr. CallumDurward (SEAL Project)
Abstract:Information about the benefits of minimum intervention dentistry has been increasingly disseminated. New materials, procedures and techniques have been introduced to encourage adoption of the philosophy. As with any new innovation, doubts regarding claims of advantages are justified and scientific evidence has played a role in getting adoption.
The MI Panel discussion will look at specific areas where scientific evidence is currently being explored that would translate into wider adoption of practice of the minimum intervention approach. Information may provoke thoughts and ideas into future research to encourage wider adoption.
Title: Micro-invasive approaches for caries treatment
Room: Crystal II
Speaker: PD Dr. Sebastian Paris Clinic for Conservative Dentistry and Periodontology, School of Dental Medicine, Christian-Albrechts-Universitätzu Kiel, Germany
Abstract:In the past years several micro-invasive approaches have been suggested for the treatment of caries lesions to postpone or even avoid the first restorative intervention, which often initiates a ‘death spiral of restorations’. Caries sealing for example, aims at arresting caries by covering the lesion with a resinous layer, thus protecting the enamel from cariogenic acids and cutting off nutrition supply for potentially entombed bacteria. In contrast to caries sealing, where the resin coat is applied on the lesion surface, caries infiltration aims to occlude the pores within the lesion body with low viscosity light curing resins. That way, diffusion pathways are blocked and lesion progression is slowed down or even arrested. The presentation will address the current scientific evidence on micro-invasive treatment approaches, show their clinical application and give a perspective on future developments.
Title: Cutting-edge applied materials and technology in Adhesive Dentistry
Room: London I
Speaker: Dr. Toru Nikaido
Cariology and Operative Dentistry, Department of Oral Health SciencesGraduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.
Abstract: Recent progress of adhesive material and technology has been remarkable. The concept of minimal cavity preparation has become widely accepted for the placement of direct composite restorations by using an adhesive system.Using various electron microscopy techniques, it has been demonstrated that resistance of enamel and dentin to acid attack could be increased in an acid-base resistant zone beneath the adhesive interface, following the application of acidic monomers incorporated into self-etching dental adhesives. It was proposed that the diffusion of the acidic monomers beyond the classic interface could result in formation of stable organic-inorganic complexes in ion-exchange interactions with the available hydroxyapatite, and that the structures should be termed “super tooth”, as it would in concept withstand major causes of destruction of the dental tissue. It was also reported that release of fluoride from the biomaterial could contribute to reinforcement of the tissue.
The success of the indirect metal-free restorations, such as indirect composite and ceramic inlay/onlay restorations, depends on good bonding between tooth structures and the restorative materials. Since the dentin bonding of the resin cement is still unreliable, the resin coating technique has been introduced into the indirect esthetic restorations, in which the exposed dentin surface is sealed by the adhesive material to protect dentin and pulp, and enhance dentin bonding durability. This technique can also be applied to natural tooth structures to create super tooth. Recent findings suggested that the all-in-one adhesive materials have the potential to cover exposed root dentin surfaces and prevent caries formation. Using the self-etching technology, formation of “super tooth” is a key strategy to improve the quality of life in the super age society.The recent findings on the ultra-morphological characteristics of super enamel and super dentin, and clinical applications of the advanced materials and technique are presented in this symposium.
Speaker: Dr. Takuichi Sato
Tohoku University Graduate School of Dentistry
Title:Molecular biological profiling of oral biofilm: Quantitative and qualitative analyses
Abstract: The profiling of oral biofilm microbiota (OM) has been traditionally performed by cultivation on agar media (e.g., Hashimoto et al 2011, Komori et al 2012, Takeuchi et al 2012), although this procedure is relatively time-consuming and labor-intensive. In addition, the existence of culture-difficult oral bacteria has been reported, and thus the entire composition of OM cannot be fully determined by only cultivation. In this study, quantitative and qualitative analyses (profiling) of OM by culture-independent methods in our laboratories were reviewed. i) Utilizing fluorescence reagents and a membrane filter (Bioplorer), rapid detection and quantification of bacteria of OM were found to be successfully performed (Sato et al 2012). ii) PCR-amplification and random cloning of 16S rRNA genes has been widely used. It is possible to detect specifically and quantify target bacteria in OM by the species-specific PCR including quantitative PCR (Abikoet al 2010). The sequence analysis of 16S rRNA genes is informative on the classification and identification of bacteria in general, and thus the method has been a promising approach to the entire understanding of OM (e.g., Ito et al 2012). Because of the PCR bias, DNA from only major components of OM is reportedly amplified by PCR (Kawamura et al 2012).iii) In addition to the various molecular biological methods mentioned above, metagenomic analysis, using the high-speed sequencer, is available on the analysis of OM (Kawamura et al 2012). Although the high-cost of the method remains to be conquered, the procedure is one of the most promising technologies. Based on the metagenomic analysis of OM using the next generation sequencer, it might be possible to diagnose and evaluate the significance of dental treatments in the future.
Speaker: Prof. Atsuo Amano
Osaka University Graduate School of Dentistry
Title:Molecular basis of periodontal destruction by Porphyromonasgingivalis
Abstract: Gingival epithelial cells function as an innate host defense system to prevent intrusion by periodontal bacteria. Nevertheless, Porphyromonasgingivalis, the most well-known periodontal pathogen, can enter gingival epithelial cells and pass through the epithelial barrier into deeper tissues.P. gingivalis fimbriae specifically interact with α5β1-integrin of epithelial cells. The bacterium is then subsequently captured by cellular pseudopodia, which enables invagination through the endosomal pathway. Following passage through the epithelial barrier, intracellular P. gingivalis impairs integrin-related signaling molecules, paxillin, and focal adhesion kinase, which disables cellular migration and proliferation. Thereafter some intracellular bacteriaaresorted to lytic compartments, including autolysosomes and late endosomes/lysosomes, while a considerable number of the remaining organisms are sorted to recycling endosomes, leading to bacterial exit from infected cells toneighboring cells, a mechanism of cell-to-cell spreading in periodontal tissue.
Most Gram-negative bacteria including P. gingivalisproduce outer membrane vesicles (MVs) which are natural vehicles, or bacterial “bombs,” for directed intercellular transport of bacterial virulence factors into host cells and tissues.P.gingivalis-MVs retain a full complementof outer membrane constituents including LPS, gingipains and fimbriae. Although P. gingivalis-MVsare suspected to invade various host cells, it is absolutely unknown how P. gingivalis-MVs invade the cells.We analyzed the invasion of host cells and cellular impairment by P. gingivalis-MVs.The remarkable strategies used by P. gingivalis to destruct periodontal tissues will be introduced.
Speaker: Dr. Takako Nakajima
Niigata University Medical and Dental Hospital
Title:Regulatory cell subsets in the pathogenesis of periodontitis
Abstract: It is well-recognized that periodontal disease results from the complex interaction between host’s defense mechanisms and periodontal pathogens. T cells play the central role in the control of the hosts’ immune system. T cells are classified into effector T cells and regulatory T cells based on the functional characteristics and a delicate balance between effector and regulatory subsets is required for immune homeostasis. Over the past twenty years, immunopathogenesis of periodontal disease was described mainly by Th1/Th2 theory. However, involvement of regulatory T-cell subset is increasingly acknowledged. This subset includes CD4+CD25+ regulatory T cells (Tregs) and natural killer T (NKT) cells. They are implicated self-tolerance and immune homeostasis.
We have shown that Tregs infiltrated into periodontitis tissues with increasing proportions of B cells relative to T cells. Expression of mRNA for TGF-1 and IL-10, which are known to be regulatory cytokines, were higher in periodontitis compared with gingivitis. T cell clones established from human periodontitis tissues expressed FOXP3 gene which is the lineage-specific transcription factor. We have also reported increased infiltration of NKT cells in periodontitis lesions. NKT cells recognize glycolipid antigens in a CD1d-restricted manner. Most of B cells in periodontitis lesion expressed CD1d. These findings from human in vivo data suggest that Tregs and NKT cells may play regulatory roles in B-cell-predominant periodontal diseases.
While, our in vitro and mouse experiment data indicated that the cells considered regulatory T cells do not necessarily suppressed immune responses against periodontal pathogens. Human CD4+CD25+FOXP3+ T cells accelerate other T cell proliferation and some of those cells could convert to Th17 phenotype by Porphyromonasgingivalis stimulation. NKT cell-deficient mice demonstrated severer alveolar bone resorption compare to wild type mice in oral infection mouse model with P. gingivalis.
Regulatory phenotype cells may function as regulatory cells or effector cells according to the circumstances.
IADR SEA Mini-Symposium
Room: VA drawing
Speaker: Dr. PasuthaThunyakitpisal
Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand, 2Department of Science, Rungsit University, Patumthani, Thailand
Title:Acemannan Induced Tooth Socket Healing: Clinical and Animal Studies
Abstract: Objective: To investigate effect of acemannan, a polysaccharide extracted from aloe vera gel, on bone formation in tooth socket healing models Method: In an animal study, lower right incisors of male Sprague-Dawley rats were pull out and an acemannan sponge was inserted into the socket. After 2 and 4 weeks, the lower jaws were dissected. Dual energy X-ray absorptiometry and histopathological examinations were used to evaluate bone formation. For clinical study, mandibular impacted teeth were extracted, and an acemannan sponge was placed in the socket. The periapical radiographs were taken immediately and 3 months after operation to evaluate bone formation. The data were collected and analyzed by SPSS program. Result:In vivo and clinical data revealed that acemannan-treated groups had significantly higher bone mineral density and faster bone healing compared with untreated controls. From histopathological results showed a massive ingrowth of bone trabeculae was detected in acemannan-treated groups. Conclusion: From our limit data, acemannan could function as a bioactive molecule stimulating bone formation.
Speaker: Dr. SitthichaiKoontongkaew
Faculty of Dentistry, Thammasat University, Pathum-Thani, Thailand
Title:ZingiberCassumunarAnd Its Potential Uses In Oral Health
Abstract: Medicinal herbs have been used for centuries to prevent and treatment different oral diseases. However, the major drawback of herbal therapies in oral diseases is the lack of scientific evidence supported to their use. ZingiberCassumunar(‘Phlai’ in Thai) has been used in Thai traditional medicine, especially in the treatment of inflammation. Objective: The objective of this study was to evaluate the ability and mechanism of action of ZingiberCassumunar with regard to the inhibition of MMPs, COX-2, PGE-2, MAPKs and iNOS expression in human gingival fibroblasts (HGFs), human dental pulp cells (HDPCs) and RAW264.7 macrophages treated with lipopolysaccharide (LPS) Methods: HGFs), HDPCs and RAW264.7 macrophages were treated with LPS in the presence or absence of the ethanol extract of ZingiberCassumunarand its constituents. The levels of expression of COX-1, COX-2, MMPs and MAPKs were determined in treated HGFs. In addition, PGE-2 and iNOS were measured in treated HDPCs and RAW264.7 macrophages, respectively. Results: ZingiberCassumunarextract could inhibit MAPKs activation, MMPs activities and COX-2 expression in HGFs treated with LPS. ZingiberCassumunar constituents including cis-3-(3′,4′-Dimethoxyphenyl)-4-[(E)-3"',4"'dimethoxystyryl]cyclohex-1-ene (compound B), cis-3-(2′,4′,5′-Trimethoxyphenyl)-4-[(E)-2"',4"',5"'trimethoxystyryl]cyclohex-1-ene (compound C) and (E)-1-(3′,4′-Dimethoxyphenyl)but-1,3-diene (DMPBD) could reduce the PGE-2 level and COX-2 expression in LPS-stimulated HDPCs. In contrast, cis-3-(3′,4′-Dimethoxyphenyl)-4-[(E)-2"',4"',5"'trimethoxystyryl]cyclohex-1-ene (compound C) reduced PGE-2 levels but had less effect on COX-2 in LPS-treated HDPCs. The ZingiberCassumunar extract and its constituents showed no significant change on COX-1 expression in HGFs and HDPCs treated with LPS. In addition, compound D could inhibitiNOS expression through the suppression of NF-κB in LPS-stimulated macrophages. Conclusion: Our results suggest that ZingiberCassumunar (Phlai) has anti-inflammatory potency. Therefore, this herb may be good alternatives to current treatments for oral diseases but it need more clinical studies.
Speaker: Dr. Lijian Jin
Faculty of Dentistry, University of Hong Kong, Hong Kong, Hong Kong
Title:Traditional Chinese Medicine for Periodontal Care–Rationale and Scientific Evidence
Abstract: Objective: Periodontal disease is one of the major global oral health burdens, and severe periodontitis remains the primary cause of tooth loss in adult population worldwide. Current scientific evidence shows that periodontal destruction largely results from pathogenic plaque biofilm-induced, uncontrolled immuno-inflammatory responses that are significantly influenced by genetic, epigenetic and environmental/acquired risk factors in susceptible individuals. Host modulatory therapy is therefore increasingly recognized as an important approach in effective management of periodontal disease. This presentation will highlight the current concepts of periodontal etiopathogenesis and elaborate the rationale of Traditional Chinese Medicine (TCM) as a potential adjunct to periodontal treatment. Recent relevant research findings are presented and discussed. Methods: The work to be presented is based upon the critical review of key scientific literature in periodontal etiopathogenesis, rationale of host modulatory therapy, and the related TCM studies for periodontal care. Results: TCM as the ‘medicine of balance’ has its great advantage in host modulation. It has been used as an adjunct for treating chronic inflammatory diseases like periodontal disease for many years. The recent in vitro and in vivo studies show that TCM may significantly modulate bacteria-induced host inflammatory response and contribute to controlling periodontal disease. Conclusion: Emerging evidence shows that TCM may be a potential host response modulator for adjunctive treatment of periodontal disease. Further basic, translational and clinical studies are highly warranted.
Speaker: Dr. Malanie S. Djamil
Department of Biochemistry – Oral Biology, Trisakti University, Jakarta Barat, Indonesia
Title:The Effect of Indonesia Natural Materials for Dentistry Fileds
Abstract: Objective:About 300 years ago, the Indonesia ancestors have been using drugs from natural ingredients that sources from environment of the surrounding forest. Indonesia is one of the countries around the Southeast Asia region that have similar climate and natural resources with other countries in the same region. Natural materials, especially plants, have long been used in the health sector for the purposes of preventive, curative, and rehabilitative. However, medication or treatment option must be scientifically proven, both in terms of the benefits and safety (WHO, 2000). All of it is set in Article 47 of the Law of the Republic of Indonesia Number 23 of 1992 on Health. Method: In dentistry fields the majority more than 90% are an action, and natural materials can be use as one of the choices in dental treatments. As natural materials, have many advantages compare to the disadvantages as long as the role of SEES can be obtained. Result: Ranges of more than 50 studies in natural materials done by Trisakti and many natural materials research in the field of dentistry in Indonesia. As an examples of Anacardiumoccidentale as a fissure sealant, Achatinafulica’s, Aloe vera and Clitoria ternate for wound healing, Salvadorepersica, honey, propolis, Piper betle L., inhibit the growth of S. mutans, Strawberry, Saccharumspontaneum L., for a teeth whitening of external discoloration materials. While there are many more materials that have not been studied in research such as Cinnamomumverum for antibacterial, Virgin coconut oil to cure the gingivitis and many others natural materials. Conclusion: More countries in Southeast Asia need to intensified joint research and collaborations in the many fields of natural material research with the goal to produce a ready-made medicine in dentistry to be worldwide community utilization.
August 22, 2013
ARCPOH, University of Adelaide, Australia
Title: Methods in Population Oral Health Research
Room: London I
Time: 16.00 – 18.00
Organizer: Gloria Mejia (University of Adelaide, Australia),
Title: Sampling strategies in population oral health research – the ARCPOH experience
Presenter: Sergio Chrisopoulos, ARCPOH, University of Adelaide, Australia
Summary: Sampling plays a vital role in population research. Each sampling unit must be representative of the entire population in order for the results to be truly generalisable. The aims here are to present sampling issues that one encounters when conducting population based research by embedding them in the context of research conducted at ARCPOH.
Time: 30 minutes (includes Q&A)
Title: Cohort Studies or Life course oral epidemiology?
Presenter: Marco Peres, ARCPOH, University of Adelaide, Australia.
Summary: Life course epidemiology is the study of the effect of early life harmful and beneficial exposures on diseases and disorders later on. The aims are to present the application of early life theories on oral health outcomes using examples from three population-based birth cohort studies.
Time: 30 minutes (includes Q&A)
Title: Application of generic health state measures to oral health studies.
Presenter: David Brennan, ARCPOH, University of Adelaide, Australia.
Summary: Oral specific measures are typically used to assess outcomes of oral disorders. However, generic measures can add additional information including health utility. The aims are to assess the use of generic health state measures in oral health studies and analyse the responsiveness of a generic measure (EQ-5D) and compare this with an oral health measure (OHIP-14).
Time: 30 minutes (includes Q&A)
Title: Quantitative bias analysis in oral health research.
Presenter: Gloria Mejia, ARCPOH, University of Adelaide, Australia
Summary:Current epidemiologic thinking encourages the application of quantitative bias analysis to evaluate the influence of systematic error on study results. Although qualitative assessments of study limitations are quite frequent in oral health research, the quantification of bias is seldom presented in published studies. The aims are to present an overview and examples of methods used for simple quantitative bias analyses in oral health epidemiology.
Time: 30 minutes (includes Q&A)
Title: New Calcium and Fluoride-based Remineralisation Technologies: Clinical Application and Methodologies for Measuring Remineralisation.
Room: Crystal I
Time: 16:00 – 17:00
Speaker: E. C. Reynolds and N. J. Cochrane
Melbourne Dental School, Oral Health CRC, The University of Melbourne
Abstract: New calcium and fluoride-based remineralisation technologies have been developed and various methodologies have been used to assess their remineralisation potential using different in vitro, in situ or in vivo models. The methodologies for measuring remineralisation have included surface microhardness, quantitative light-induced fluorescence (QFL), electron probe microanalysis (EMPA) and transverse microradiography (TMR). The validity of the different models and remineralisation assessment methodologies will be discussed as will the results achieved with these new remineralisation technologies. Based on this review recommendations for clinical application will also be discussed.