Modelling the national economic burden of non-surgical periodontal management in specialist clinics in Malaysia using a markov model

BACKGROUND

Non-surgical periodontal treatment is the mainstay of periodontal treatment. In Malaysia, the prevalence of periodontal disease is substantial among adults with almost half of them having periodontitis. Therefore, we estimated the economic burden of non-surgical periodontal treatment in specialist clinics in Malaysia.

METHODS

Relevant data from multiple data sources which include national oral health and health surveys, national census, extensive systematic literature reviews, as well as discussion with experts, were used to estimate the economic burden of non-surgical periodontal management in specialist clinics in Malaysia in 2020. This estimation was done from the oral healthcare provider's perspective in both public and private sectors using an irreducible Markov model of 3-month cycle length over a time horizon of one year.

RESULTS

In 2020, the national economic burden of non-surgical periodontal treatment during the first year of periodontal management in specialist clinics in Malaysia was MYR 696 million (USD 166 million), ranging from MYR 471 million (USD 112 million) to MYR 922 million (USD 220 million). Of these, a total of MYR 485 million (USD 115 million) and MYR 211 million (USD 50 million) were the direct oral healthcare cost in public and private dental clinics, respectively.

CONCLUSION

The findings of this study demonstrated substantial economic burden of non-surgical periodontal management in specialist clinics in Malaysia. Being a life-long disease, these findings highlight the importance of enforcing primary and secondary preventive measures. On the strength and reliability of this economic evidence, this study provides vital information to inform policy- and decision-making regarding the future direction of managing periodontitis in Malaysia.

Utilizing decision tree machine model to map dental students' preferred learning styles with suitable instructional strategies

BACKGROUND

Growing demand for student-centered learning (SCL) has been observed in higher education settings including dentistry. However, application of SCL in dental education is limited. Hence, this study aimed to facilitate SCL application in dentistry utilising a decision tree machine learning (ML) technique to map dental students' preferred learning styles (LS) with suitable instructional strategies (IS) as a promising approach to develop an IS recommender tool for dental students.

METHODS

A total of 255 dental students in Universiti Malaya completed the modified Index of Learning Styles (m-ILS) questionnaire containing 44 items which classified them into their respective LS. The collected data, referred to as dataset, was used in a decision tree supervised learning to automate the mapping of students' learning styles with the most suitable IS. The accuracy of the ML-empowered IS recommender tool was then evaluated.

RESULTS

The application of a decision tree model in the automation process of the mapping between LS (input) and IS (target output) was able to instantly generate the list of suitable instructional strategies for each dental student. The IS recommender tool demonstrated perfect precision and recall for overall model accuracy, suggesting a good sensitivity and specificity in mapping LS with IS.

CONCLUSION

The decision tree ML empowered IS recommender tool was proven to be accurate at matching dental students' learning styles with the relevant instructional strategies. This tool provides a workable path to planning student-centered lessons or modules that potentially will enhance the learning experience of the students.

Evaluating the potential of matrix metalloproteinase as a diagnostic biomarker in rheumatoid arthritis and periodontitis: A systematic review and meta-analysis

BACKGROUND

Matrix metalloproteinases (MMPs) play a crucial role in the pathogenesis of several chronic diseases including rheumatoid arthritis (RA) and periodontitis (PD). RA patients with periodontitis (RA-PD) are associated with elevated inflammatory burden due to increased production of proinflammatory cytokines. Controlling upregulated MMPs activity in these patients may have potential therapeutic effects. Therefore, aim of this study is to address the focused question: "Do RA subjects with concurrent PD have different levels of MMPs in comparison to RA alone, PD alone and HC subjects?"

METHODS

The systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search from 4 electronic databases (EMBASE, Medline, Web of Science, and Cochrane library) and manual search was performed from inception to July 2023. Quality assessment of each article was done using Newcastle-Ottawa Scale. Meta-analyses derived results were summarized as standardized mean difference (SMD) with 95% confidence intervals.

RESULTS

A total of 879 articles were extracted. Following screening and full text assessment, 9 studies were included. MMP-1, MMP-3, MMP-8, MMP-9, and MMP-13 were consistently elevated in RA-PD subjects. MMP-8 levels were found to be higher in RA-PD subjects compared with RA alone, PD alone, and HC in 3 studies reporting GCF levels (SMD = 1.2; Z = 2.07; P = .04) and 2 studies reporting serum levels (SMD = 0.87; Z = 4.53; P < .00001).

CONCLUSION

RA-PD group showed significantly higher MMP levels in their serum and GCF compared with HC, RA, and PD alone individuals. MMP-8 may serve as a reliable biomarker in the diagnosis and management of RA-PD subjects.

Is microbial adhesion affected by the build orientation of a 3-dimensionally printed denture base resin?

STATEMENT OF PROBLEM

How the build orientation of a 3-dimensionally (3D) printed denture affects microbial adhesion is unclear.

PURPOSE

The purpose of this in vitro study was to compare the adherence of Streptococcus spp. and Candida spp. on 3D-printed denture bases prepared at different build orientations with conventional heat-polymerized resin.

MATERIAL AND METHODS

Resin specimens (n=5) with standardized 28.3 mm² surface area were 3D printed at 0 and 60 degrees, and heat-polymerized (3DP-0, 3DP-60, and HP, respectively). The specimens were placed in a Nordini artificial mouth (NAM) model and exposed to 2 mL of clarified whole saliva to create a pellicle-coated substratum. Suspensions of Streptococcus mitis and Streptococcus sanguinis, Candida albicans and Candida glabrata, and a mixed species, each at 10⁸ cfu/mL were pumped separately into the model for 24 hours to promote microbial adhesion. The resin specimens were then removed, placed in fresh media, and sonicated to dislodge attached microbes. Each suspension (100 μL) was aliquoted and spread on agar plates for colony counting. The resin specimens were also examined under a scanning electron microscope. The interaction between types of specimen and groups of microbes was examined with 2-way ANOVA and then further analysis with Tukey honest significant test and Kruskal-Wallis post hoc tests (α=.05).

RESULTS

A significant interaction was observed between the 3DP-0, 3DP-60, and HP specimen types and the groups of microbes adhering to the corresponding denture resin specimens (P<.05). The difference was statistically significant among 3DP-0, 3DP-60, and HP specimens (P<.05). The adherence of candida was 3.98-times lower on the 3DP-0 than that of HP (P<.05). However, adherence of the mixed-species microbes and streptococci on the 3DP-60 were 1.75 times and 2-fold higher, respectively (P<.05). The scanning electron micrographs showed that 3DP-0 exhibited the lowest microbial adherence compared with HP and 3DP-60.

CONCLUSIONS

Adherence affinity of denture base resin is affected by the build orientation rather than by the group of different microbes. Three-dimensionally printed denture base resin fabricated at a 0-degree build orientation exhibited low affinity for microbial adhesion. Three-dimensionally printed dentures may reduce microbial adhesion when printed at a 0-degree build orientation.

Systemic Antibiotics as an Adjunct to Subgingival Debridement: A Network Meta-Analysis

This review aimed to evaluate the effectiveness of systemic antibiotics as adjunctive treatment to subgingival debridement in patients with periodontitis. Randomized controlled trials were included that assessed the effectiveness of systemic antibiotics in improving periodontal status, indicated by clinical attachment gain level, probable pocket depth reduction, and bleeding on probing reduction of patients with any form of periodontitis at any follow-up time. Network meta-analyses with a frequentist model using random effects was employed to synthesize the data. The relative effects were reported as mean difference with a 95% confidence interval. Subsequently, all treatments were ranked based on their P-scores. A total of 30 randomized controlled trials were included in this network meta-analyses. Minimally important clinical differences were observed following the adjunctive use of satranidazole, metronidazole, and clindamycin for clinical attachment gain level and probable pocket depth reduction. For bleeding on probing reduction, minimally important clinical differences were observed following the adjunctive use of metronidazole and a combination of amoxycillin and metronidazole. However, the network estimates were supported by evidence with certainty ranging from very low to high. Therefore, the findings of this network meta-analyses should be interpreted with caution. Moreover, the use of these antibiotics adjunct to subgingival debridement should be weighed against possible harm to avoid overuse and inappropriate use of these antibiotics in patients with periodontitis.

Antibodies against citrullinated proteins in relation to periodontitis with or without rheumatoid arthritis: a cross-sectional study

Background

Previous studies have reported conflicting findings between serum anti-citrullinated protein antibodies (ACPA) levels in rheumatoid arthritis (RA) participants with and without periodontitis (Pd). This study aimed to analyse possible correlations between serum ACPA levels and clinical parameters in Pd and RA participants.

Methods

Full mouth periodontal examination (probing pocket depth, clinical attachment levels, gingival bleeding index, visual plaque index) was conducted and serum samples obtained from 80 participants comprising RA, Pd, both RA and Pd (RAPd) and healthy individuals (HC). Erythrocyte sedimentation rates (ESR) and periodontal inflamed surface area (PISA) were obtained. Serum samples were analysed for ACPA quantification using enzyme-linked immunosorbent assay (ELISA).

Results

Median levels (IU/mL) of ACPA (interquartile range, IQR) in RAPd, RA, Pd and HC groups were 118.58(274.51), 102.02(252.89), 78.48(132.6) and 51.67(91.31) respectively. ACPA levels were significantly higher in RAPd and RA as compared to HC group (p < 0.05). However, ACPA levels of any of the groups were not correlated with any clinical periodontal and RA parameters within the respective groups.

Conclusions

At individual level, the amount of serum ACPA seem to have an increasing trend with the diseased condition in the order of RAPd > RA > Pd > HC. However, lack of any significant correlation between the serum ACPA levels with the clinical Pd and RA parameters warrants further studies to investigate the causal link between RA and Pd for such a trend. Further studies involving more inflammatory biomarkers might be useful to establish the causal link between Pd in the development and progression of RA or vice versa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01712-y.

Influence of scaler tip design on root surface roughness, tooth substance loss and patients' pain perception: an in vitro and a randomised clinical trial

Background

The influence of scaler tip design on root surface roughness, tooth substance loss and patients’ pain perception is investigated.

Methods

This article was divided into the following parts: Part 1 Surface roughness and substance loss: an in vitro study, which involves intact extracted teeth sectioned and treated using a piezoelectric ultrasonic device (PM200 EMS Piezon, Switzerland) with a conventional scaler tip (FS-407) and a Perio Slim (PS) scaler tip (Perio Slim DS-016A). All sectioned samples for tooth surface roughness (n = 20) and tooth substance loss (n = 46) analyses were measured and compared using a 3D surface texture analyser and scanning electron microscope (SEM) respectively, at baseline and following scaling. Part 2 Pain Perception: a clinical study, which was a split mouth study design including 30 participants with gingivitis and/or mild chronic periodontitis; treated with supra-gingival scaling from teeth #13 to #23. Subjects were randomised to group A or group B. Group A was treated first with PS scaler tips, whereas group B was treated first with conventional scaler tips. Pain perception was recorded using the visual analogue scale (VAS).

Results

In vitro study: both scaler tips caused significant reduction in root substance roughness after scaling (p < 0.05), but no significant difference between the two scaler tips (p > 0.05) was observed. The PS scaler tip caused statistically significantly less root substance loss (p < 0.05) when the initial thickness of the tooth was < 1000 µm. Clinical study: the participants reported significantly lesser pain score during scaling using the PS scaler tip (median: 3) than when using the conventional scaler tip (median: 5) (p < 0.05).

Conclusions

In the in vitro study, using a slim scaler tip design causes less tooth substance loss compared to a wider scaler tip design. In the clinical study, less pain was observed compared than a wide (conventional) scaler tip design.

Clinical Efficacy of Single Application Local Drug Delivery and Adjunctive Agents in Nonsurgical Periodontal Therapy: A Systematic Review and Network Meta-Analysis

This review aimed to rank the clinical efficacy of commercially available single-application local drug delivery and adjunctive agents (LDAs) compared with subgingival mechanical debridement (SMD) in nonsurgical periodontal therapy (NSPT). Randomized controlled clinical trials that compared LDAs against SMD alone or with placebo in adults (aged at least 18 years) diagnosed with periodontitis with a minimum of 6 months follow-up were included. A frequentist approach to random-effects network meta-analysis was implemented. The efficacies of the LDAs measured by probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain were reported as mean difference (MD) with 95% confidence intervals (CIs). The treatments were ranked according to their P-score. Four network meta-analyses suggested that sulfonic/sulfuric acid gel (PPD MD −1.13 mm, 95% CI −1.74 to −0.53, P-score 0.91; CAL MD −1.09 mm, 95% CI −1.58 to −0.61, P-score 0.95) and doxycycline hyclate gel (PPD MD −0.90 mm, 95% CI −1.50 to −0.30, P-score 0.93; CAL MD −0.84 mm, 95% CI −1.40 to −0.28, P-score 0.92) were the most effective in reducing PPD and gaining CAL in split-mouth and parallel studies, respectively (moderate certainty of evidence). LDAs have differing efficacies, but they present with possible clinical significance over SMD alone in NSPT.

Impact of non-surgical periodontal therapy on serum Resistin and periodontal pathogen in periodontitis patients with obesity

BACKGROUND

Non-surgical periodontal therapy (NSPT) known as gold standard treatment in managing periodontitis. The aim of this study was to investigate the response of NSPT in periodontitis subjects who were obese. Clinical parameters of periodontitis, changes in serum resistin and periodontal pathogens in subgingival plaque were compared before and after NSPT in periodontitis subjects who were obese and with normal weight.

METHODS

A total of 48 periodontitis subjects (obese, n = 18; normal weight, n = 30) were recruited (hereafter will be referred as participants) to participate into a prospective, before and after clinical trial. Obesity status is defined by body mass index (BMI) criteria (obese: ≥30 kg/ m²; normal weight < 25 kg/m²). Visible Plaque Index (VPI), Gingival Bleeding Index (GBI), Probing Pocket Depth (PPD) and Clinical Attachment Loss (CAL) were recorded; and serum and plaque were collected at baseline and following 12 weeks post-NSPT. Serum resistin level was analyzed using enzyme-linked immune-sorbant assay (ELISA), while detection of periodontal pathogens in dental plaque were carried out using real time PCR (qPCR).

RESULTS

Following NSPT, means VPI and GBI showed significant improvement between obese and normal weight groups (p <  0.05), but no difference in means PPD and CAL was observed between groups. Obesity remained as a predictor for VPI and GBI after adjusting for smoking habit. No significant difference was observed in serum resistin level and mean counts for P. gingivalis, T. forsythia, and P. intermedia between obese and normal weight groups following NSPT.

CONCLUSIONS

Regardless of obesity status, NSPT has a significant impact on VPI and GBI in periodontitis subjects. However, the impact of NSPT towards serum resistin and periodontal pathogens was non-significant in those with periodontitis.

TRIAL REGISTRATION

This study followed the Consolidation Standards of Reporting Trials Statement and retrospectively registered on 26/11/2015 at clinicaltrials.gov (No. NCT02618486).

Commercial Local Pharmacotherapeutics and Adjunctive Agents for Nonsurgical Treatment of Periodontitis: A Contemporary Review of Clinical Efficacies and Challenges

Periodontal infections tend to be site-specific, mostly confined to the periodontal pocket. With the surge of antibiotic-resistant bacteria, the trend is shifting towards other therapeutic modalities, especially locally delivered approaches that include other pharmacotherapeutic drugs and medical devices. This narrative review aimed to provide insights into the clinical efficacy of local drug delivery and adjunctive agents used in nonsurgical management of periodontitis. Electronic (PubMed/MEDLINE, CENTRAL, and EMBASE) and bibliographic searches of past systematic reviews were carried out to identify previous publications on the topic. Only relevant literature and randomized controlled trials published in English were selected. In addition, a literature review was developed based on the selected articles. Experimental drugs or agents were excluded. This review highlights the clinically proven and commercially available therapeutic agents related to the management of periodontal disease with comparisons of their clinical efficacies and challenges. A vast array of commercial local pharmacotherapeutic agents had been clinically tested, but the methodologies and clinical results varied within and between each agent used, causing difficulty in drawing conclusions and providing support to the superiority of one agent over another. Considering the benefit-cost ratio with the modest clinical results, the long-term usefulness of these agents remains debatable.

Impact of Severe Chronic Periodontitis on Oral Health-related Quality of Life

PURPOSE

To assess the impact of extent and severity of chronic periodontitis (CP) on oral health-related quality of life (OHRQoL).

MATERIALS AND METHODS

A cross-sectional comparative study was performed on subjects from multiple dental centres in Malaysia using a questionnaire covering sociodemographics, OHRQoL using the Malaysian Oral Health Impact Profile questionnaire, OHIP-14(M) and self-reported symptoms. Participants with severe CP were age-and gender-matched with periodontally healthy/mild periodontitis (HMP) participants based on inclusion and exclusion criteria. Full mouth periodontal examination was performed on participants. Outcome measures were OHIP-14(M) prevalence of impact and severity of impact scores.

RESULTS

One hundred and thirty (130) participants comprising 65 severe CP and 65 HMP participants were included in the study. Prevalence of impact on OHRQoL was significantly higher in the severe CP than HMP group, with an odds ratio of 3. Mean OHIP-14(M) score was significantly higher in the severe CP (18.26 ± 10.22) compared to HMP (11.28± 8.09) group. The dimensions of psychological discomfort and functional limitation, and factors such as 'discomfort due to food stuck' and 'felt shy' were impacted more in severe CP compared to HMP group (p < 0.05). When compared with the HMP group, generalised severe CP participants showed higher prevalence of impact on OHRQoL [OR=5] (p < 0.05) compared to localised severe CP [OR=2] (p = 0.05). Participants who had experienced self-reported symptoms had statistically significant impacts on OHRQoL.

CONCLUSIONS

Severe CP had a greater impact on OHRQoL compared to HMP. Impacts were mainly for functional limitation and psychological discomfort dimensions. When considering extent of disease, the impact on OHRQoL was mostly in generalised severe CP subgroup.

Dental students' perceptions on the contribution and impact role of a clinical teacher

OBJECTIVES

This study was conducted in University of Malaya to evaluate student perceptions on the contribution and role of an effective clinical teacher based on the cognitive apprenticeship model in clinical practice.

METHODS

Self-administered questionnaires were distributed to 233 undergraduate dental students involved with clinical teaching. This modified and validated questionnaire focusing on students' learning environment was used in order to gain relevant information related to dental clinical teaching. Six domains with different criteria applicable to clinical teaching in dentistry were selected consisting of modelling (four criteria), coaching (four criteria), scaffolding (four criteria), articulation (four criteria), reflection (two criteria) and general learning environment (six criteria). Data analyses were performed using IBM SPSS Statistics 20.

RESULTS

Majority of the students expressed positive perceptions on their clinical learning experience towards the clinical teachers in the Faculty of Dentistry, University of Malaya, in all criteria of the domains. Few negative feedbacks concerning the general learning environment were reported.

CONCLUSION

Further improvement in the delivery of clinical teaching preferably by using wide variety of teaching-learning activities can be taken into account through students' feedback on their learning experience.

Impact of non-surgical periodontal therapy on OHRQoL in an obese population, a randomised control trial

Background

Oral Health Related Quality of Life (OHRQoL) is an important measure of disease and intervention outcomes. Chronic periodontitis (CP) is an inflammatory condition that is associated with obesity and adversely affects OHRQoL. Obese patients with CP incur a double burden of disease. In this article we aimed to explore the effect of Non-Surgical Periodontal Therapy (NSPT) on OHRQoL among obese participants with chronic periodontitis.

Materials and Methods

This was a randomised control clinical trial at the Faculty of Dentistry, University of Malaya. A total of 66 obese patients with chronic periodontitis were randomly allocated into the treatment group (n=33) who received NSPT, while the control group (n=33) received no treatment. Four participants (2 from each group) were non-contactable 12 weeks post intervention. Therefore, their data were removed from the final analysis. The protocol involved questionnaires (characteristics and OHRQoL (Oral Health Impact Profile-14; OHIP-14)) and a clinical examination.

Results

The OHIP prevalence of impact (PI), overall mean OHIP severity score (SS) and mean OHIP Extent of Impact (EI) at baseline and at the 12-week follow up were almost similar between the two groups and statistically not significant at (p=0.618), (p=0.573), and (p=0.915), respectively. However, in a within-group comparison, OHIP PI, OHIP SS, and OHIP EI showed a significant improvement for both treatment and control groups and the p values were ((0.002), (0.008) for PI), ((0.006) and (0.004) for SS) and ((0.006) and (0.002) for EI) in-treatment and control groups, respectively.

Conclusion

NSPT did not significantly affect the OHRQoL among those obese with CP. Regardless, NSPT, functional limitation and psychological discomfort domains had significantly improved.

Trial registration

(NCT02508415). Retrospectively registered on 2^nd of April 2015.

Electronic supplementary material

The online version of this article (10.1186/s12955-017-0793-7) contains supplementary material, which is available to authorized users.

Resistin as potential biomarker for chronic periodontitis: A systematic review and meta-analysis

OBJECTIVES

To determine the serum and gingival crevicular fluid (GCF) levels of resistin between individuals with chronic periodontitis (CP) and those without CP, and to evaluate the role of resistin in CP.

MATERIALS AND METHODS

The addressed focused question was "Is there a difference in the resistin levels between individuals with CP and those without CP?" four electronic databases: Medline, PubMed (National Institutes of Health, Bethesda), EMBASE, and Science direct databases from 1977 up to March 2016 for appropriate articles addressing the focused question. EMBASE and Medline were accessed using OVID interface which facilitated simultaneous search of text words, MeSH or Emtree. Unpublished studies (gray literature) were identified by searching the Open-GRAY database and references of the included studies (cross referencing) were performed to obtain new studies. In-vitro studies, animal studies, studies that reported levels of other cytokines but not resistin, letters to the editor and review papers were excluded.

RESULTS

Ten studies were included. Nine studies compared resistin levels between CP and periodontally healthy (H) individuals and reported higher mean serum and GCF levels of resistin in CP patients than the H controls. Two studies showed comparable resistin levels from GCF and serum between diabetes mellitus with CP (DMCP) and CP groups. Three studies included obese subjects and showed comparable serum and GCF resistin levels between obese subjects with CP (OBCP) and CP subjects.

CONCLUSIONS

CP patients were presented with elevated levels of GCF or serum resistin as compared with H individuals. Resistin modulates inflammation in chronic periodontal disease and may be used as surrogate measure to identify subjects at risk for periodontitis. Resistin levels in patients with CP and systemic inflammatory disorders such as diabetes, obesity, or rheumatoid arthritis was not significantly higher than the levels in patients with only CP.

Prevalence of chronic periodontitis in an obese population: a preliminary study

Background

Chronic periodontitis (CP) is a global public health issue. Studies have suggested CP could be linked to obesity due to their similar pathophysiological pathway. The aim of this study is to determine the prevalence of CP and to assess the predictors for CP among the obese Malaysian population.

Methods

This is a cross-sectional study on obese participants. Obesity is defined as an individual who has Body Mass Index (BMI) ≥27.5 kg/m². A convenience sampling method was used. A total of 165 paricipants were recruited. This study involved answering questionnaires, obtaining biometric and clinical measurements of Visible plaque index (VPI), Gingival bleeding index (GBI), Probing pocket depth (PPD) and Clinical attachment loss (CAL). Data analysis was carried out using SPSS statistical software (SPSS Inc., version 20, US).

Results

A total of 165 participants; 67 (40.6 %) males and 98 (59.4 %) females participated in the study. Mean age of the participants was 43.9 (±8.9). The prevalence of CP among the obese population was found to be 73.9 %. Out of this, 43 and 55 % were categorised as moderate and severe CP respectively. Around 64 % of participants had sites with CAL ≥4 mm and participants with sites with PPD ≥4 mm were reported to be 25 %. Around 83 % of the participants had sites with GBI ≥30 and 92 % of participants had sites with VPI ≥20 %. GBI and VPI were found to have significantly higher odds for CP.

Conclusion

Prevalence of CP was high among obese Malaysians. GBI and VPI were potential predictors for CP in this obese population.

Role of antimicrobial photodynamic therapy in the treatment of aggressive periodontitis: A systematic review

BACKGROUND

The aim was to assess the efficacy of antimicrobial photodynamic therapy (aPDT) in the treatment of aggressive periodontitis (AgP).

METHODS

The addressed focused question was "Is aPDT effective in the treatment of AgP?" MEDLINE/PubMed, EMBASE, Scopus, ISI Web of knowledge and Google-Scholar databases were searched from 1977 till May 2015 using combinations of the following keywords: antimicrobial; photochemotherapy; photodynamic therapy; photosensitizing agents; AgP; scaling and root-planing (SRP). Reviews, case reports, commentaries, and articles published in languages other than English were excluded.

RESULTS

Seven studies were included. In 5 studies, aPDT was performed as an adjunct to SRP. Laserwavelengths and duration of irradiation ranged between 660-690 nm and 60-120 s, respectively. Laser power output as reported in 2 studies was 75 mW. One study showed significant improvement in periodontal parameters for subjects receiving aPDT as an adjunct to SRP as compared to treatment with SRP alone at follow up. However, comparable periodontal parameters were reported when aPDT as an adjunct to SRP was compared to SRP alone in the treatment of AgP in one study. One study showed comparable outcomes when aPDT was compared to SRP in the treatment of AgP. In two studies, adjunctive antibiotic administration to SRP showed significantly better outcomes when compared to application of adjunctive use of aPDT to SRP.

CONCLUSION

aPDT is effective as an adjunct to SRP for the management of AgP, however, further randomized clinical trials with well defined control groups are needed in this regard.

Establishing and managing a periodontal biobank for research: the sharing of experience

Periodontal bio-repositories, which allow banking of clinically validated human data and biological samples, provide an opportunity to derive biomarkers for periodontal diagnosis, prognosis and therapeutic activities which are expected to improve patient management. This article presents the establishing of the Malaysian Periodontal Database and Biobank System (MPDBS) which was initiated in 2011 with the aim to facilitate periodontal research. Partnerships were established with collaborating centres. Policies on specimen access, authorship and acknowledgement policies were agreed upon by all participating centres before the initiation of the periodontal biobank. Ethical approval for the collection of samples and data were obtained from institutional ethics review boards. A broad-based approach for informed consent was used, which covered areas related to quality of life impacts, genetics and molecular aspects of periodontal disease. Sample collection and processing was performed using a standardized protocol. Biobanking resources such as equipment and freezers were shared with the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). In the development of the MPDBS, challenges that were previously faced by the MOCDTBS were considered. Future challenges in terms of ethical and legal issues will be faced when international collaborations necessitate the transportation of specimens across borders.

Moving into a new era of periodontal genetic studies: relevance of large case-control samples using severe phenotypes for genome-wide association studies

Studies to elucidate the role of genetics as a risk factor for periodontal disease have gone through various phases. In the majority of cases, the initial 'hypothesis-dependent' candidate-gene polymorphism studies did not report valid genetic risk loci. Following a large-scale replication study, these initially positive results are believed to be caused by type 1 errors. However, susceptibility genes, such as CDKN2BAS (Cyclin Dependend KiNase 2B AntiSense RNA; alias ANRIL [ANtisense Rna In the Ink locus]), glycosyltransferase 6 domain containing 1 (GLT6D1) and cyclooxygenase 2 (COX2), have been reported as conclusive risk loci of periodontitis. The search for genetic risk factors accelerated with the advent of 'hypothesis-free' genome-wide association studies (GWAS). However, despite many different GWAS being performed for almost all human diseases, only three GWAS on periodontitis have been published - one reported genome-wide association of GLT6D1 with aggressive periodontitis (a severe phenotype of periodontitis), whereas the remaining two, which were performed on patients with chronic periodontitis, were not able to find significant associations. This review discusses the problems faced and the lessons learned from the search for genetic risk variants of periodontitis. Current and future strategies for identifying genetic variance in periodontitis, and the importance of planning a well-designed genetic study with large and sufficiently powered case-control samples of severe phenotypes, are also discussed.