The COVID-19 pandemic and its global effects on dental practice. An international survey

Objectives A multicentre survey was designed to evaluate the impact of COVID-19 outbreak on dental practice worldwide, estimate the COVID-19 related symptoms/signs, work attitudes and behaviour and the routine use of protective measures and personal protective equipment (PPE). Methods A global survey using a standardized questionnaire with research groups from 36 countries was designed. The questionnaire was developed and pretested during April 2020 and contained three domains: 1) personal data; 2) COVID-19 positive rate and symptoms/signs presumably related to the coronavirus; 3) working conditions and PPE adopted after the outbreak. Countries’ data were grouped by the country positive rate (CPR) during the survey period and by Gross-National-Income per capita. An ordinal multinomial logistic regression model was carried out with COVID-19 self-reported rate referred by dental professionals as dependent variable to assess the association with questionnaire items. Results A total of 52,491 questionnaires were returned with a male/female ratio of 0.63. Out of the total respondents, 7,859 dental professionals (15%) reported symptoms/signs compatible with COVID-19. More than half of the sample (n=27,818; 53%) stated to use FFP2/N95 masks, while 21,558 (41.07%) used eye protection. In the bivariate analysis, CPR and N95/FFP2 were significantly associated (OR=1.80 95%CI=1.60/2.82 and OR=5.20 95%CI=1.44/18.80, respectively), while Gross-National-Income was not statistically associated with CPR (OR=1.09 95%CI=0.97/1.60). The same significant associations were observed in the multivariate analysis. Conclusions Oral health service provision has not been significantly affected by COVID-19, although access to routine dental care was reduced due to country-specific temporary lockdown periods. While the dental profession has been identified at high-risk, the reported rates of COVID-19 for dental professionals were not significantly different to those reported for the general population in each country. These findings may help to better plan oral health care for future pandemic events

Factors influencing resonance frequency analysis assessed by Osstell™mentor during implant tissue integration: I. Instrument positioning, bone structure, implant length

Aim: To monitor longitudinally the development of implant stability of SLA Straumann ® tissue-level implants using resonance frequency analysis (RFA) and to determine the influence of instrument positioning, bone structure and implant length on the assessment of RFA. Material and methods: Thirty-two healthy adult patients received either 8 mm, ∅4.1 mm Straumann ® Standard Plus tissue-level implants (n=16: Group A) or 10 mm, ∅4.1 mm Straumann ® Standard Plus tissue-level implants (n=16: Group B). During healing, RFA was performed on Weeks 0,1, 2, 3, 4, 5, 6, 8 and 12. The implants were restored after 10 weeks (impression taking) and 12 weeks. In addition, probing depth, presence of plaque and bleeding on probing were assessed. Implant stability quotient (ISQ) values of Groups A and B were compared using unpaired t-tests and longitudinally applying paired t-tests between Week 0 and the subsequent time points. Results: Positioning of the Osstell ™mentor device did not affect the ISQ values. Generally, ISQ values increased continuously during healing from a mean of 65.1 (SD 16.97) to 74.7 (SD 5.17) (significantly from Week 0 to Weeks 6, 8 and 12). Lower bone density (Type III or IV) resulted in significantly lower ISQ values up to Week 8. Implant length affected the increase in ISQ values over time. While no significant increase was observed with 10 mm implants, ISQ values of 8 mm implants increased significantly from Week 0 to Weeks 6, 8 and 12. Conclusions: Using Osstell ™mentor, ISQ values are reproducible irrespective of instrument positioning. ISQ values are affected by the bone structure and implant length. Hence, no predictive values can be attributed to implant stability. © 2010 John Wiley & Sons A/S.link_to_subscribed_fulltex

Oral microbial biofilm models and their application to the testing of anticariogenic agents

OBJECTIVES: This review paper evaluates the use of in vitro biofilm models for the testing of anticariogenic agents. DATA: Caries is a biofilm-mediated oral disease and in vitro biofilm models have been widely utilised to assess how anticariogenic or antimicrobial agents affect the de/remineralisation process of caries. The use of enamel or dentine substrata has enabled the assessment of the relationship between bacterial activity and caries lesion initiation and progression and how this relationship could be affected by the agent under study. SOURCES: Only papers published in the English literature were reviewed. STUDY SELECTION: Both 'open' and 'closed' biofilm systems utilising either single or multiple-species as defined or undefined inocula are analysed. CONCLUSIONS: There is a wide variety of in vitro biofilm models used in the assessment of anticariogenic agents. A reproducible model that mimics the shear forces present in the oral environment, and uses a defined multiple-species inocula on tooth substrates can provide valuable insight into the effectiveness of these agents. CLINICAL RELEVANCE: Biofilm models are important tools for the testing of the mechanism of action and efficacy of novel anticariogenic agents. Results from these experiments help facilitate the design of randomised, controlled clinical trials for testing of efficacy of the agents to provide essential scientific evidence for their clinical use

Anti-caries effect of CPP-ACP in irradiated nasopharyngeal carcinoma patients

OBJECTIVE: The aim of this study was to determine the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on caries progression in irradiated nasopharyngeal carcinoma (NPC) patients. METHODS: Twenty-one males and three females (median age, 50 years) were randomized into two groups before radiotherapy. Subjects had at least eight teeth after oral health clearance. The test group used 0.4 % stannous fluoride gel and a crème containing 10 % CPP-ACP daily; the control group used a similar crème without CPP-ACP and otherwise identical care. Subjects applied the crème three times daily and fluoride gel once daily. Caries status, saliva and plaque parameters were measured pre-radiotherapy, at 2 weeks and 3 months post-radiotherapy. RESULTS: Baseline International Caries Detection and Assessment System (ICDAS) scores were 0-1126 surfaces (93.9 %), 1-28 surfaces (2.3 %), 2-40 surfaces (3.3 %) and 3-6 surfaces (0.5 %) for the control and 0-1186 surfaces (95.6 %), 1-31 surfaces (2.5 %), 2-15 surfaces (1.2 %) and 3-8 surfaces (0.7 %) for the test group. Twenty-two subjects returned at 3 months post-radiotherapy with reduced plaque pH, salivary flow, pH and buffering capacity. Nine test and 8 control subjects developed 32 and 59 new caries lesions, respectively. Test subjects showed lower caries progression than the controls: all surfaces (OR 0.51, 95 % CI 0.17∼1.59), occlusal (OR 0.20, 95 % CI 0.03∼1.29) and smooth surfaces (OR 0.61, 95 % CI 0.16∼2.38). The difference was not statistically significant. CONCLUSION: Application of CPP-ACP did not significantly reduce caries progression in NPC patients in the first 3 months after radiotherapy as compared to controls. CLINICAL RELEVANCE: Adjunct use of CPP-ACP with stannous fluoride gel in irradiated NPC patients gave comparable results compared to stannous fluoride gel alone in reducing caries progression

Anticariogenic efficacy of a saliva biomimetic in head-and-neck cancer patients undergoing radiotherapy

BACKGROUND: The aim of this study was to investigate the effect of treatment with the saliva biomimetic, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and SnF2 /NaF compared with SnF2 /NaF alone on coronal surface caries progression in head-and-neck cancer patients undergoing radiotherapy. METHODS: Twenty-four participants were randomized into two groups. Both groups used 0.4% SnF2 gel and a 0.32% NaF toothpaste; the test group also applied a crème containing 10% CPP-ACP three times daily while the control group used an identical crème without CPP-ACP (placebo). Resting saliva flow rate and saliva fluoride concentrations were determined. Caries status was assessed using ICDASII at baseline and 12-weeks postradiotherapy. Data were statistically analysed using a linear mixed effects model. RESULTS: Both groups showed significantly reduced resting saliva flow rate (P < 0.001) postradiotherapy. There were no significant differences in flow rates and fluoride concentration between groups. The CPP-ACP group exhibited a significant (P < 0.05) 51% reduction in coronal surface caries progression compared with the placebo group. CONCLUSION: Resting salivary flow rate was significantly reduced in head-and-neck cancer patients following radiotherapy and use of CPP-ACP with SnF2 /NaF significantly lowered caries progression compared with SnF2 /NaF alone

Self-assembly of dental surface nanofilaments and remineralisation by SnF2 and CPP-ACP nanocomplexes

Dental caries, erosion and hypersensitivity are major public health problems. SnF2 is used widely in oral care products to help prevent/treat these conditions. Casein phosphopeptide-stabilised amorphous calcium phosphate nanocomplexes (CPP-ACP) are a biomimetic nanotechnology of salivary phosphopeptide-ACP complexes that deliver bioavailable calcium and phosphate ions to promote dental remineralisation (repair). We show here using in vitro studies and a double-blind, randomised controlled, cross-over design in situ clinical trial that SnF2 and CPP-ACP interact to form a nanofilament coating on the tooth surface and that together they are superior in their ability to promote dental remineralisation. Sn(II) by cross-linking the CPP-ACP helps to stabilise the complexes which improves delivery to the tooth surface and enhances binding and ion incorporation into tooth mineral. The combination of SnF2 and CPP-ACP in oral care products may significantly improve their efficacy in prevention/treatment of dental caries/erosion and hypersensitivity

Outcomes of visual tooth shade selection performed by operators with different experience

Objective To evaluate the effect of professional experience and lighting conditions on visual shade selection on natural teeth and comparing the visual-shade-selection results with those of instrumental methods. Materials and Methods Shade selection was performed on five maxillary central incisors. The 25 observers were divided into five groups according to their professional experience. Observers performed visual-shade-selection using shade guide (Vita 3D Master, Vita Zahnfabrik, Bad Sackingen, Germany) under two lighting conditions (4000 and 6500 K) from the cervical, middle and incisal thirds of the teeth. Same teeth were measured using an intraoral scanner (Trios 3Shape, Copenhagen, Denmark) and spectrophotometer (Vita Easyshade Compact, Vita Zahnfabrik, Bad Sackingen, Germany), under the same two lighting conditions. Results Visual-shade-selection outcomes were not affected by professional experience under both lighting conditions (P .05). Lighting conditions had no effect on the shade measurement outcomes of visual shade selection, Vita Easyshade Compact, and Trios 3Shape (P > .05). Conclusions Shade measurement outcomes were not affected by the lighting conditions (4000 and 6500 K). The shade measurement feature of the T-3S could be an alternative to V-ES and VSS. Clinical significance This study suggests professional experience and lighting conditions has no effect on visual shade selection. Trios 3Shape could be used for shade determination as an alternative to a Vita Easyshade Compact spectrophotometer