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

Bonding longevity of flowable GIC layer in artificially carious dentin

Purpose To evaluate the bond longevity of glass ionomer cement (GIC) to sound and artificially carious dentin, using a high viscosity material with regular consistency and using a flowable GIC, after one year water storage. Material and methods Sixty bovine incisors were polished to obtain flat buccal dentin. Thirty teeth were submitted to pH-cycling model to simulate artificial caries. Teeth from both dentin conditions (sound and caries) were randomly reassigned according to the powder/liquid ratio of the GIC (n=15): (1) regular (1:1) and (2) flowable GIC (1:2). Polyethylene tubes with internal diameter of 0.76 mm were placed over the pre-treated dentin and filled up with GIC (KetacTM Molar Easy Mix, 3M ESPE), immediately protected with a layer of petroleum jelly. Half of the specimens were evaluated by microshear bond strength test after 24 h, the other half was evaluated one year later, after water storage at 37 °C. Data (MPa) were analyzed with 3-way repeated measures ANOVA and Tukey׳s post-hoc tests (α=0.05). Results Statistical analysis revealed reduction of GIC bonding effectiveness after one year of water storage (5.4±1.4 to 3.4±1.3 MPa) (p<0.001). No significant differences were observed (p=0.126) between regular (4.2±1.8 MPa) and flowable (4.6±1.5 MPa) GIC consistency. Moreover, GIC showed better bonding effectiveness on sound (5.1±1.7 MPa) than artificially carious dentin (3.7±1.3 MPa) (p<0.001). Conclusions Both powder/liquid ratio of GIC show similar reduction of bonding effectiveness after one year, especially in artificially carious dentin substrate

Caries lesion prevention and arrestment in approximal surfaces in contact with glass ionomer cement restorations - a systematic review and meta-analysis

Background. Studies have suggested that in the presence of approximal cavities, the approximal surface in contact with this one shows a higher risk in the development of caries lesions. Aim. To evaluate the ability of dental materials to prevent and to arrest caries lesion in approximal surfaces in contact with occlusoproximal restorations. Design. Two independent reviewers performed a literature search in PubMed through November 2014. The inclusion criteria were: (1) subject related to the scope of this systematic review, (2) study with follow-up, (3) not performed in specific groups, (4) to have a comparison group. After selection by title and abstract, potentially eligible articles were read in full. Meta-analysis was carried out considering the outcome as caries lesion progression or arrestment. Results. The search strategy identified 772 potentially relevant studies, and 10 of them were included in the review (six laboratory studies and four longitudinal trials). For the longitudinal clinical trials, no difference was verified among the materials (OR = 0.680,95%CI:0.233–1.983). When a meta-analysis was performed for laboratory studies, GIC was significantly associated with better ability to arrest caries lesions (OR = 0.153,95%CI:0.060–0.391). Conclusions. In laboratory studies, GIC shows better ability to arrest caries lesion in approximal adjacent surfaces, but this ability was not confirmed in longitudinal clinical trials

Bonding behavior of restorative materials in primary teeth submitted to erosive challenge − Evidence from an in vitro study

Purpose: To evaluate bond stability of restorative materials to eroded primary teeth after aging. Methods: 120 primary molars were assigned into 12 groups, in according to substrate – enamel or dentin, precondition of substrate – sound or eroded, and restorative material – resin composite/adhesive system-RC, high-viscosity glass ionomer cement–HVGIC or resin-modified GIC–RMGIC. Eroded groups were subjected to erosive challenge prior to bonding procedures. Polyethylene tubes were placed on flat surfaces of substrates and filled up with one of materials. After 24 h, half of the specimens were submitted to microshear bond strength (BS) test, and the other half after 12 months. Results: Generally, sound substrates resulted in higher BS values than eroded ones, with exception of HVGIC that obtained similar performance in both substrates. Furthermore, the storage period negatively influenced BS values for RC groups on dentin assessment. The other groups did not show reduction in BS values after 12 months. RC showed better bonding performance than others materials. Conclusion: Previously eroded substrates result in the worst performance of RC and RMGIC. Moreover, the water storage affects the bonding stability of RC to dentin. On the other hand, HVGIC is not affected by precondition of substrate neither storage

Influência da tentativa de aceleração da reação de presa de CIVAV na resistência de união à dentina hígida de molar decíduo

Abstract: To evaluate the influence of the attempt to accelerate the prey reaction of high viscosity glass ionomer cements (CIVAV) on dentin union resistance (RU). After approval by CEP-FOUSP, 80 healthy deciduous molars allocated in 8 groups (n=10) were selected according to the presentation of civav - powder-liquid (Fuji Gold Label IX GP) - group F or encapsulated (Equi a Fil) - group E and initial prey acceleration attempt with application of ultrasound - 20s (U) or halogen light - 60s (F) or LED -60s (L) or control (C). The occlusal enamel was removed in a politriz with water sandpaper #220, after #600 for 60s to standardize dentinal mud. Under the pretreated dentin, polyethylene cannulas (1.0 mm height) were positioned and filled by the CIVAV according to the group. After storage (24h/37ºC) a microshear test (1mm/min) was performed until a fracture of the specimen occurred. After that, they were analyzed under a stereoscopic microscope (400X) to determine the type of fracture (adhesive, mixed or cohesive). The data were submitted to ANOVA and Tukey test (p<0.05). ANOVA showed statistical difference for the factor *presentation of CIVAV* and for interaction between the factors *presentation of CIVAV* and *external energy source*. The mean and standard deviation were: FU 7.73 (± 2.40)A, FF 3.70 (± 0.86)B, FL 5.84 (± 3.16)A, FC 5.64 (± 2.15)B, EU 3.51 (± 1.27)C, EF 4.82 (± 1.74)C, EL 4.44 (± 2.21)C, EC 3.29 (± 1.41)C. The predominant fracture type was mixed typ

ART is an alternative for restoring occlusoproximal cavities in primary teeth:evidence from an updated systematic review and meta-analysis

Background: A previous systematic review showed that atraumatic restorative treatment (ART) can be an option to restore the occlusoproximal cavities in primary teeth; however, few studies fulfilled the criteria of inclusion to generate a high level of evidence. Aim: To update the existing systematic review and address questions regarding survival rate of ART restorations compared to the conventional approach in occlusoproximal cavities in primary molars. Design: The search was extended beyond the original search through the PubMed/MEDLINE database up to February 2016. Furthermore, Web of Science and EMBASE were searched. The inclusion criteria were subjects related to the scope of the systematic review. After selection by title and abstract, potentially eligible articles were read in full and included in accordance with exclusion criteria. Meta-analysis was carried out with the outcome being the survival rate of restorations. Results: The search strategy identified 560 potentially relevant studies, in addition to 127 from the original systematic review. A total of four articles were included in the qualitative and quantitative analyses. Meta-analysis showed no statistically significant difference between ART and conventional approaches in survival rate of occlusoproximal cavities (OR = 0.887, 95% CI: 0.574–1.371). Conclusion: ART restorations have similar survival rate compared to conventional treatment and can be considered an option to restore occlusoproximal cavities in primary molars