Melbourne Dental School - Research Publications

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    Bonding Failures of Lingual Orthodontic Brackets: A Retrospective Study Comparing Lingual Brackets with KommonBase Extensions, to Customized Lingual Brackets
    Tepedino, M ; Mossaz, C ; Fillion, D ; Cattaneo, PM ; Cornelis, MA (MDPI, 2022-05-01)
    The aim of the present study was to evaluate in a clinical setting the bracket survival of lingual brackets bonded with the KommonBase system, and to compare it to the survival of a customized lingual bracket system. Two convenience samples of 13 consecutive patients treated with lingual fixed appliances with KommonBase extensions (Group 1) and 14 consecutive patients treated with customized Incognito™ lingual fixed appliances were retrospectively enrolled (Group 2). First time debondings were recorded from the files. Data were submitted to statistical analysis and a Log-rank test was used to compare the Kaplan–Meier survival curves between the two groups. Statistical significance was set as p < 0.05. Lingual brackets bonded with the KommonBase system showed a failure rate of 8%, while Incognito brackets showed a failure rate of 7.1%. The Log-rank test comparing the Kaplan–Meier survival curves revealed no statistically significant difference between the two groups (p = 0.343). Most debondings occurred during the first 6 months. Upper incisors and canines were less prone to debond than premolars and molars. In conclusion, no difference in bracket survival was observed between the KommonBase system and a customized lingual appliance.
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    Clinician preferences for orthodontic bracket bonding materials: a quantitative analysis
    Chee, S ; Mangum, J ; Teeramongkolgul, T ; Tan, S ; Schneider, P (Walter de Gruyter GmbH, 2022-06-01)
    Abstract Background and objectives: Many orthodontic bracket-bonding materials are available for clinical use. The current study aimed to assess the preferences and factors contributing to the clinical choice of bracket bonding material. Methods: Eight bracket bonding materials were trialled by 15 participants. The handling properties and overall ease of use of each material were scored by the participants on a Visual Analogue Scale (VAS). The participants also responded to a questionnaire regarding the use and perceptions of resin-modified glass ionomer cements (RMGICs) for bracket bonding. A quantitative analysis was conducted on the responses to the questionnaire. Results:Of all materials trialled, there was a consistent preference for the handling of resin composite (RC) materials. Fuji II LC was the highest rated RMGIC material and was considered similar to RC materials for ease of handling. Conclusions:Fuji® II LC may be a suitable alternative to RC materials for orthodontic bracket bonding. Further research is required to assess and produce bonding materials possessing anti-cariogenic properties along with comparable handling properties to bracket bonding materials that are currently preferred.
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    The Biomechanical Profile of an Osseo-Integrated Rectangular Block Implant: A Pilot In Vivo Strain Analysis
    Gazelakis, E ; Judge, RB ; Palamara, JEA ; Nazir, M (MDPI, 2022-09-01)
    Aim: To load-test the osseo-integrated rectangular block implant (RBI), measure the generated cortical peri-implant strains, and relate these findings to known human physiological parameters. Materials and methods: Two RBIs were placed into the posterior mandibular saddle in a mature greyhound dog and allowed to osseo-integrate. The half mandible (implants in situ) was mounted in a servohydraulic system. Four triple-stacked rosette gauges were placed cortically (mesial, distal, buccal, and lingual). A modified ISO-14801 protocol was used (1000 N, 300, 2 Hz, 1 h) and the generated principal strains (ep, eq) and their angular orientations (F), were calculated. Results: (1) Bucco-lingual "horizontal" dimension: dominant "horizontal" compressive stresses were on the lingual aspect and "horizontal" tensile stresses on the buccal aspect. The buccal cortex was elastically tensile-stretched, while the lingual cortex was elastically compressed. (2) Bucco-lingual "vertical" dimension: dominant vertical torsional stresses were oriented buccally and apically, with an overall buccally inclined torsional effect. This was also evidenced on the lingual aspect, where there remained high torsional rotation elements (high F and e2). (3) Mesio-distal "horizontal" dimension: dominant torsional stresses oriented as a distal-lingual "counter-clockwise" rotation. Conclusions: The applied off-axial loads generated a heterogeneous pattern of bucco-lingual and mesio-distal cortical strains, both vertically and horizontally. The short dimensioned osseo-integrated RBI design appeared to biomechanically withstand the applied loads and to maintain the strains generated to levels that were within physiological limits. More studies and statistical analyses are needed to confirm these findings.
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    Bacteroides fragilis outer membrane vesicles preferentially activate innate immune receptors compared to their parent bacteria
    Gilmore, WJJ ; Johnston, ELL ; Bitto, NJJ ; Zavan, L ; O'Brien-Simpson, N ; Hill, AFF ; Kaparakis-Liaskos, M (FRONTIERS MEDIA SA, 2022-09-20)
    The release of bacterial membrane vesicles (BMVs) has become recognized as a key mechanism used by both pathogenic and commensal bacteria to activate innate immune responses in the host and mediate immunity. Outer membrane vesicles (OMVs) produced by Gram-negative bacteria can harbor various immunogenic cargo that includes proteins, nucleic acids and peptidoglycan, and the composition of OMVs strongly influences their ability to activate host innate immune receptors. Although various Gram-negative pathogens can produce OMVs that are enriched in immunogenic cargo compared to their parent bacteria, the ability of OMVs produced by commensal organisms to be enriched with immunostimulatory contents is only recently becoming known. In this study, we investigated the cargo associated with OMVs produced by the intestinal commensal Bacteroides fragilis and determined their ability to activate host innate immune receptors. Analysis of B. fragilis OMVs revealed that they packaged various biological cargo including proteins, DNA, RNA, lipopolysaccharides (LPS) and peptidoglycan, and that this cargo could be enriched in OMVs compared to their parent bacteria. We visualized the entry of B. fragilis OMVs into intestinal epithelial cells, in addition to the ability of B. fragilis OMVs to transport bacterial RNA and peptidoglycan cargo into Caco-2 epithelial cells. Using HEK-Blue reporter cell lines, we identified that B. fragilis OMVs could activate host Toll-like receptors (TLR)-2, TLR4, TLR7 and nucleotide-binding oligomerization domain-containing protein 1 (NOD1), whereas B. fragilis bacteria could only induce the activation of TLR2. Overall, our data demonstrates that B. fragilis OMVs activate a broader range of host innate immune receptors compared to their parent bacteria due to their enrichment of biological cargo and their ability to transport this cargo directly into host epithelial cells. These findings indicate that the secretion of OMVs by B. fragilis may facilitate immune crosstalk with host epithelial cells at the gastrointestinal surface and suggests that OMVs produced by commensal bacteria may preferentially activate host innate immune receptors at the mucosal gastrointestinal tract.
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    A retrospective study of drugs associated with xerostomia from the Australian Database of Adverse Event Notifications.
    Choo, PJ ; Taing, M-W ; Teoh, L (Oxford University Press (OUP), 2022-09-01)
    OBJECTIVES: Xerostomia is a subjective sensation of dry mouth associated with many medications and increases the risk of tooth decay and other oral complications. The aim of this study was to identify unreported medications associated with dry mouth from the Australian Database of Adverse Event Notifications (ADAEN) from the Therapeutic Goods Administration (TGA) in Australia. METHODS: This was a descriptive retrospective study. A request was made to the TGA to provide all reports associated with dry mouth. De-identified reports were provided from the commencement of the database in 1971 until June 2020. Drugs were divided into established drugs that are associated with xerostomia in the primary literature and secondary drugs not reported in the primary literature. KEY FINDINGS: There were 1927 individual case reports for dry mouth associated with medications. Of these, there were 1379 reports of established (primary) drugs and 1481 reports of secondary drugs associated with xerostomia. Dry mouth was found to be associated with many medication classes; analgesics, cardiovascular and gastrointestinal drugs had the greatest number of secondary drugs reported. CONCLUSIONS: A comprehensive list of suspected medications associated with xerostomia has been established. This adds to the growing catalogue of medications associated with dry mouth, where several medications have not previously been identified in the primary literature.
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    Stability, survival, and patient satisfaction with CAD/CAM versus conventional multistranded fixed retainers in orthodontic patients: a 6-month follow-up of a two-centre randomized controlled clinical trial
    Gera, A ; Pullisaar, H ; Cattaneo, PM ; Gera, S ; Vandevska-Radunovic, V ; Cornelis, MA (OXFORD UNIV PRESS, 2022-08-14)
    OBJECTIVES: The primary aim of this two-arm parallel two-centre randomized controlled trial was to compare computer-aided design and computer-aided manufacturing (CAD/CAM) versus conventional multistranded fixed retainers (FRs) in terms of stability over 6 months. Secondary outcomes were failure rates and patient satisfaction. METHODS: Patients were randomized to CAD/CAM or conventional FRs in both arches, in 1:1 ratio and blocks of four. Allocation concealment was secured by using sequentially numbered envelopes. Patients were blinded. Retainers were bonded at the end of orthodontic treatment (T0), and patients were recalled after 1 (T1), 3 (T3), and 6 (T6) months. First-time retainer failures were recorded and digital impressions were taken. Arch widths and lengths, as well as Little's Irregularity Index (LII), were measured. Additionally, patients answered satisfaction questionnaires. Linear mixed models were applied for measurements and patient satisfaction. Survival analyses were estimated with Kaplan-Meier curves, along with Cox-regression modelling. RESULTS: One hundred and eighty-one patients were randomized (98 in Centre 1, and 83 in Centre 2): Ninety in the CAD/CAM group and 91 in the conventional group. Three subjects dropped out at baseline, as they did not attend any of the follow-up appointments.168 patients attended the T6 visit. There were no significant differences in arch dimensions between T0 and T6, whilst the LII was different only in the CAD/CAM group (mean difference: 0.2 mm; 95% confidence interval: 0.1 to 0.4; P < 0.001). Within 6 months, 39 upper retainers (19 out of 88 CAD/CAM and 20 out of 90 conventional retainers) and 52 lower retainers failed (26 out of 88 CAD/CAM and 26 out of 90 conventional retainers), with no significant difference between the survival of both types of retainers (hazard ratios conventional to CAD/CAM: upper arch: 0.99 [P =0.99], lower arch: 0.93 [P = 0.80]). There were no significant changes in patient satisfaction between the groups. No harms were observed. CONCLUSIONS: There were no clinically significant differences in LII, arch widths and lengths between CAD/CAM and conventional retainers after 6 months. There was no difference in failures and in patient satisfaction between both types of FRs. REGISTRATION: ClinicalTrials.gov NCT04389879.
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    Cultural Competence in the nursing, dentistry, and medicine professional curricula: a qualitative review.
    Klenner, M ; Mariño, R ; Pineda, P ; Espinoza, G ; Zaror, C (Springer Science and Business Media LLC, 2022-09-20)
    BACKGROUND: Cultural competence development in the formative process of healthcare professionals is crucial for the provision of culturally appropriate health care. This educational issue is highly relevant in the growing multicultural composition of southern Chile. The objective of this study was to examine how the healthcare professions curricula at the Universidad de La Frontera, in La Araucanía Region, prepares future professionals to respond to patients' cultural needs. METHOD: A sequential transformative mixed methods design composed of two phases was carried out. Phase 1 reviewed all printed material and documentation to explore content that developed cross-cultural skills and competencies in the curricula. In Phase 2 semi-structured interviews were conducted with academics with responsibilities for the development of the curriculum in each career, to detect how academics envisage the incorporation of cultural competence in the curricula. RESULTS: Regarding curricular contents, findings indicated that the healthcare professions curricula at The Universidad de La Frontera have similar approaches to the inclusion of CCT in subjects' syllabuses, with inclusion of the different CCT, particularly in the Dental and Medical curricula. However, this coverage showed significant variations in the undergraduate healthcare curricula. The analysis revealed that themes around the Ethics and human values for professional practice; the Psychosocial and cultural determinants of health; the Relationship health-family-community, and to a lesser extent, the Clinician-patient relationship were well covered in the courses. On the other hand, Inequalities in health was the theme with the least contact time in all three courses. Academics called for a better organisation of the inclusion of CCT in the curricula. They also highlighted the challenges of maintaining the dominant paradigm underlying healthcare models, practices, and orientations within the academic staff and health discipline. CONCLUSION: Curricula contents findings indicate that the healthcare professions curricula at Universidad de La Frontera have similar approaches to the inclusion of CCT in subjects' syllabuses. However, its depth of coverage allows for improvements. The systematization of CCT and teaching-learning methodologies in healthcare professions curricula is necessary to develop formative processes that allow future professionals to be aware of and respectful with patients' cultural characteristics and needs.
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    Economic Evaluations of Preventive Interventions for Dental Caries and Periodontitis: A Systematic Review
    Tan, MN ; Tonmukayakul, U ; Le, LK-D ; Calache, H ; Mihalopoulos, C (SPRINGER INT PUBL AG, 2022-09-12)
    OBJECTIVES: To critically examine the methods used for full economic evaluations of preventive interventions for dental caries and periodontitis. METHODS: Published literature post-2000 was searched to April 2021. Based on a developed intervention classification framework for dental caries and periodontitis, only universal, selective or indicated interventions were included in this review. The Drummond 10-point checklist was used for quality appraisal. RESULTS: Of 3,007 unique records screened for relevance, 73 studies were reviewed. Most model-based studies (61/73) used cost-effectiveness analysis (49%) or cost-benefit analysis (28%). Trial-based studies (16/73) commonly used cost-effectiveness analysis (59%). Four studies used both economic evaluation methods. Sixty-four papers (88%) were on dental caries, eight papers (11%) focused on periodontitis, and one paper (1%) included both oral diseases; 72% of model-based and 82% of trial-based studies were of good quality. The most frequently investigated dental caries preventive interventions were water fluoridation (universal intervention; cost-saving or cost-effective), fissure sealant and fluoride varnish (selective and indicated interventions; cost-effectiveness outcomes were inconsistent). Supportive periodontal therapy with oral health education (indicated intervention; cost-effective) was the most frequently evaluated preventive intervention for periodontitis. Thirty percent of studies with a time horizon > 1 year did not apply an appropriate discount rate and 26% did not comprehensively discuss other important considerations beyond the technical analysis. CONCLUSIONS: Generic health outcome measures should be incorporated for economic evaluations on preventive interventions for dental caries and periodontitis, and an increased focus to prevent periodontitis using economic evaluation methods is needed to inform resource allocation and policy decision-making.
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    Patients with post-COVID-19 vaccination facial palsy: To boost or not to boost?
    Cirillo, N ; Orlandi, M ; Colella, G (DE GRUYTER POLAND SP Z O O, 2022-08-22)
    A possible association between Bell's palsy and COVID-19 vaccination has been suggested. While it is likely that COVID-19 vaccine recipients from the general population do have a slightly increased risk of developing Bell's palsy, there are little data regarding this risk in individuals with a history of disease. Gaining a better understanding of this association is particularly important for informing evidence-based recommendations regarding future booster shots in subjects who developed Bell's palsy as a side effect of vaccination, or as a result of SARS-CoV-2 infection. We previously described the first case of COVID-19 vaccine-related Bell's palsy; here we report an 18-month clinical and electromyographic follow-up and discuss the implications of receiving further vaccine doses in patients with positive disease history.
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    Antibiotic prophylaxis at the time of dental implant placement: a cost-effectiveness analysis.
    Zhurakivska, K ; Russo, LL ; Muzio, LL ; Caponio, VCA ; Laino, L ; Arena, C ; Cirillo, N ; Troiano, G (Springer Science and Business Media LLC, 2022-08-22)
    BACKGROUND: Antibiotic prophylaxis during implant placement may improve implant short term survival. Nevertheless, use of antibiotics carries risks of adverse effects and antibiotic resistance. The aim of the present study is to compare the use of antibiotics in dental implant procedures in terms of costs and effectiveness. METHODS: A decision-tree model was developed using TreeAge Pro Healthcare software. Two strategies were compared: Antibiotics and No antibiotics in implant placement procedures. The costs were calculated considering direct costs for implant placement, antibiotic costs, and costs for implant replacement in case of failure. Effectiveness was defined in terms of General Oral Health Assessment Index. Outcomes were evaluated as Incremental Cost Effectiveness Ratio (ICER). One-way sensitivity analysis and Probabilistic Sensitivity Analysis were performed for the most influential variables to test parameter uncertainty. Patient and healthcare perspectives were considered. RESULTS: Antibiotic prophylaxis resulted to be cost-effective compared to no use of antibiotics (ICER = 14,692,64 and ICER = 3841,18, respectively for patient's and healthcare perspective). The cost of antibiotics, cost of implant replacement in case of failure and probability of adverse effects significantly influenced the results. CONCLUSIONS: From an individual patient perspective, antibiotic strategy can be considered cost-effective, even when the cost of antibiotic therapy increases. We can conclude that the administration of antibiotics in association with implant placement is recommended in clinical practice, as it increases the success rate and makes the treatment more effective. However, attention should be placed when healthcare perspective is considered, particularly in terms of antibiotic resistance that may impact public health and associated costs.