The Effect of Stacking on the Accuracy of 3D-Printed Full-Arch Dental Models.

The objective of this study was to assess the effect of stacking on the dimensional and full-arch accuracy of 3D-printed models, utilising a standardised assessment methodology. A previously validated methodology involving a standard tessellation language image (STL) reference model, comprising seven spheres on a horseshoe base resembling a dental arch, was used. Six 3D-designed STL models were prepared, optimised, and stacked horizontally using 3D Sprint software. The stacking file was transferred to the NextDent 5100 printer to build the physical models. To assess accuracy, a coordinate measuring machine (CMM) measured the diameter of the spheres n=210, and twenty-one vectors extended between the centres of each of the seven spheres (n = 630). When compared to the reference model, significant differences were observed for dimensional (p = 0.006) and full-arch accuracy (p = 0.006) for all stacked models. Additionally, significant differences were observed between the stacked models for the dimensional accuracy between the posterior (p = 0.015), left posterior (p = 0.005) and anteroposterior (p = 0.002). The maximum contraction was observed in the fourth stacked model, which demonstrated the highest median deviation and least precision within the full-arch (MD = 666 µm, IQR = 55 µm), left posterior (MD = 136 µm, IQR = 12 µm), posterior (MD = 177 µm, IQR = 14 µm) and anteroposterior (MD = 179 µm, IQR = 16 µm) arch segments. In general, the anterior and left posterior arch segments recorded the highest contractions with a median deviation of 34 µm and 29 µm, and precision of 32 µm and 22 µm, respectively. Statistically significant differences were observed between the stacked models in terms of dimensional accuracy that were within clinically acceptable thresholds. The greatest contraction was noted in the fourth model, displaying the least full-arch accuracy compared to the other models. Stacked, additively manufactured, full arch models are a viable alternative for diagnostic, orthodontic, and single-unit prosthodontic applications. In contrast, caution should be exercised when utilising stacked models for full arch high accuracy prosthodontic applications. Further research is needed to assess the impact of additional variables including different printers and resins.

A systematic review on neutrophils interactions with titanium and zirconia surfaces: Evidence from in vitro studies.

OBJECTIVES: This systematic review aimed to assess in vitro studies that evaluated neutrophil interactions with different roughness levels in titanium and zirconia implant surfaces. MATERIAL AND METHODS: An electronic search for literature was conducted on PubMed, Embase, Scopus, and Web of Science and a total of 14 studies were included. Neutrophil responses were assessed based on adhesion, cell number, surface coverage, cell structure, cytokine secretion, reactive oxygen species (ROS) production, neutrophil activation, receptor expression, and neutrophil extracellular traps (NETs) release. The method of assessing the risk of bias was done using the toxicological data reliability assessment tool (TOXRTOOL). RESULTS: Ten studies have identified a significant increase in neutrophil functions, such as surface coverage, cell adhesion, ROS production, and NETs released when interacting with rough titanium surfaces. Moreover, neutrophil interaction with rough-hydrophilic surfaces seems to produce less proinflammatory cytokines and ROS when compared to naive smooth and rough titanium surfaces. Regarding membrane receptor expression, two studies have reported that the FcγIII receptor (CD16) is responsible for initial neutrophil adhesion to hydrophilic titanium surfaces. Only one study compared neutrophil interaction with titanium alloy and zirconia toughened alumina surfaces and reported no significant differences in neutrophil cell count, activation, receptor expression, and death. CONCLUSIONS: There are not enough studies to conclude neutrophil interactions with titanium and zirconia surfaces. However, different topographic modifications such as roughness and hydrophilicity might influence neutrophil interactions with titanium implant surfaces.

Development and validation of the parenting and child tooth brushing assessment questionnaire.

OBJECTIVE: We report the development and validation of a comprehensive Parenting and Child Tooth brushing Assessment (PACTA) questionnaire. METHODS: This cross-sectional study was conducted with community-recruited Australian parents (N = 450) of children aged 2-8 years. Parents completed an online survey including the newly developed PACTA (comprising four scales assessing children's tooth brushing behaviours, parenting strategies, attitudes and knowledge) and established scales assessing parenting behaviours, attitudes and self-efficacy. RESULTS: Exploratory factor analyses revealed two-factor structures for scales assessing child behaviour ('noncompliance' and 'avoidance behaviour'), parenting strategies ('effective strategies' and 'ineffective strategies') and attitudes ('emotional reactions' and 'lack of concern'), whereas the knowledge scale was unidimensional. Internal consistencies were satisfactory (>0.7) for all except the knowledge scale. There was good evidence of convergent and predictive validity. All subscales predicted children's parent-reported tooth brushing frequency; children were more likely to brush at least twice per day when parents reported fewer tooth brushing behavioural problems, using effective parenting strategies, and having better attitudes and knowledge. Poorer scores on the 'lack of concern' subscale of the attitudes scale were the strongest unique predictor of twice-daily brushing (OR, 95% CI: 1.51, 1.36-1.67). CONCLUSIONS: PACTA demonstrates satisfactory validity and reliability. Further research assessing sensitivity to change following intervention is warranted.

Longevity of Polymer-Infiltrated Ceramic Network and Zirconia-Reinforced Lithium Silicate Restorations: A Systematic Review and Meta-Analysis.

The purpose of this study was to systematically review the existing literature to assess the clinical survival and success of PICN and ZLS indirect restorations as the clinical evidence for them remains lacking. PubMed, SCOPUS, Embase, Cochrane Library, Web of Science, LILACs, and SciElo databases were searched from 1 January 2000 to 1 February 2021. Clinical trials and cohort studies published in English were included while case studies, case series, and in vitro studies were excluded. Results were analyzed qualitatively and a meta-analysis using a random effects model was performed. A strength of recommendation taxonomy (SORT) analysis was conducted and risk of bias (RoB) was assessed using the Newcastle-Ottawa scale and Cochrane RoB tools. An electronic search through the databases yielded 2454 articles, of which 825 remained after duplicate removal. Five studies investigating PICN and four investigating ZLS indirect restorations remained after assessing for eligibility. The overall survival rate of PICN over 1 year was 99.6% and 99.2% over 2 years. The overall survival rate of ZLS over 1 year was 99%. The main mode of failure for both materials was catastrophic fracture. One study had a high RoB, four had a moderate RoB, and four had a low RoB. Both materials demonstrated moderate strength of recommendation at a level 2 evidence for all studies based on SORT analysis. PICN and ZLS show promising short-term clinical performance as full and partial coverage indirect restorations, but longer follow-up studies are required to confirm their long-term performance.

Carious lesions in permanent dentitions are reduced in remote Indigenous Australian children taking part in a non-randomised preventive trial.

We tested the effect of an annual caries preventive intervention, delivered by a fly-in/fly-out oral health professional team, with Indigenous children residing in a remote Australian community. Around 600 Indigenous children aged 5 to 17 years were invited to participate at baseline, of who 408 had caregiver consent. One hundred and ninety-six consented to the epidemiological examination and intervention (Intervention group) and 212 consented to the epidemiological examination only (Comparison group). The intervention, which occurred annually, comprised placement of fissure sealants on suitable teeth, and application of povidone-iodine and fluoride varnish to the whole dentition, following completion of any necessary restorative dental treatment. Standard diet and oral hygiene advice were provided. Caries increment (number of tooth surfaces with new dental caries) in both deciduous and permanent dentitions was measured at the 2-year follow-up. Comparison group children had significantly higher number of new surfaces with advanced caries in the permanent dentition than the Intervention group (IRR = 1.61; 95% CI: 1.02-2.54; p = 0.04); with a preventive fraction of 43%. The effect of intervention remained significant with children in the Comparison group developing significantly more advanced caries lesions in the permanent dentition than the Intervention group children in the adjusted multivariable analysis (IRR = 2.21; 95% CI: 1.03-4.71). Indigenous children exposed to the intervention had less increment in advanced dental caries in the permanent dentition than those not exposed to the intervention.

A Call for Action to Safely Deliver Oral Health Care during and Post COVID-19 Pandemic.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak started just a couple of months ago and it grew rapidly causing several deaths and morbidities. The mechanism behind the transmission of the virus is still not completely understood despite a multitude of new specific manuscripts being published daily. This article highlights the oral cavity as a possible viral transmission route into the body via the Angiotensin converting enzyme 2 receptor. It also provides guidelines for routine protective measures in the dental office while delivering oral health care.

Novel corona virus disease (COVID-19) awareness among the dental interns, dental auxiliaries and dental specialists in Saudi Arabia: A nationwide study.

BACKGROUND: Dental health care workers (DHCW's) are invariably at a higher risk of contracting COVID-19. The objectives were; to investigate the current knowledge on COVID-19 among the DHCW's; and to conduct quasi-experiment among the DHCW's who were unaware of the disseminated COVID-19 information. METHODS: A nationwide cross-sectional study targeting dental interns, auxiliaries, and specialists with a two-staged cluster sampling technique was performed. A 17-item questionnaire was subjected to reliability and validity tests before being administered. The participants for quasi-experiment were separated from the original sample after their initial response. Chi-square test assessed responses to knowledge statements between the participants. Difference in mean knowledge scores between the categories of DHCW's and sources of COVID-19 information was assessed using ANOVA. Data from the quasi experiment (pre vs post knowledge intervention) was subjected to paired t-test. Percentage of DHCWs providing correct or wrong responses to each knowledge statement at baseline and after 7 days were compared using McNemar test. RESULTS: The overall sample consisted of 706 (N) participants, and the DHCW's with no prior knowledge on COVID-19 (N=206) were part of the quasi experiment. Findings from cross-sectional study revealed that knowledge was significantly (p<0.05) related to the qualification level (interns vs auxiliaries vs specialists). However, the difference in the source of information (WHO/CDC vs Journal articles vs MoH) did not demonstrate any effect. Number of participants with correct responses to knowledge questions had significantly (p<0.05) increased after intervention. Also, the overall mean knowledge score (10.74±2.32 vs 12.47±1.68; p<0.001) had increased significantly after the intervention. CONCLUSION: In conclusion, the basic knowledge on COVID-19 among the DHCW's in Saudi Arabia is acceptable. Timely dissemination of information by the Ministry of Health, Saudi Arabia had a positive impact on the COVID-19 knowledge score of the DHCW's.

Surface-Specific Caries Preventive Effect of an Intervention Comprising Fissure Sealant, Povidone-Iodine and Fluoride Varnish in a Remote Indigenous Community in Australia.

This study evaluates the effect of a topical intervention comprising of fissure sealant, povidone-iodine, and fluoride varnish in preventing caries on occlusal, approximal, and smooth surfaces. This three-year clinical trial was conducted in a remote Indigenous community of Australia. All schoolchildren (age range: 4-17) were invited to participate; those with parental consents to receive three-annual epidemiological examinations and interventions constituted the experimental group, while those with consents for only the epidemiological examination formed a comparison group. The intervention group received an annual application of fissure sealant, povidone-iodine and fluoride varnish for two consecutive years along with the restoration of any cavitated lesions, while the comparison group did not receive any intervention except for the usual care that included emergency treatment and restorations. Incipient and advanced caries were recorded in the permanent dentition while data on confounding variables were collected through questionnaires. Caries increment and progression were the outcome variables. A total of 408 children participated in the baseline examination, 208 finished the study. After adjusting for confounders, the prevented fraction (PF) on occlusal surfaces for advanced caries in the experimental group was 76.1% (mean difference- -0.35, 95% CI: -0.67-0.04), while the PF for progression from incipient to advanced caries was 100%(mean difference- -0.30, 95% CI: -0.52-0.09). The mean number of smooth surfaces that progressed from incipient to advanced caries in the comparison group was more than twice that of the experimental group, the mean difference was -0.25 (95% CI: -0.46--0.03) with a PF of 61%. The intervention was only effective in preventing advanced caries on occlusal surfaces and in halting the progression of caries on occlusal and smooth surfaces but not on approximal caries.

Demonstration of high value care to improve oral health of a remote Indigenous community in Australia.

BACKGROUND: The oral health of Indigenous children in remote communities is much worse than other population groups in Australia. Providing and maintaining an oral health service is challenging due to the remoteness of communities, the associated high cost, and the low retention of clinical staff. An annual preventive intervention delivered by fly-in clinicians may be a more cost-effective way to manage this problem. In this analysis we estimate the cost-effectiveness of an annual professional intervention for the prevention of dental caries in children of a remote Indigenous community in Far North Queensland. METHODS: A cost-effectiveness analysis was conducted based on an annual preventive intervention protocol. This included treating all dental decay in those with disease, applying fissure sealants, a disinfectant swab, fluoride varnish and providing oral hygiene instructions and dietary advice to all participating school children. This study included an intervention group and a natural comparison group and both groups were followed-up for 2 years after the initial preventive intervention. A Markov model was built to assess the cost-effectiveness of the intervention compared with the usual care. Costs of treatment from the Queensland Department of Health were used and effectiveness was measured as quality-adjusted life years (QALYs) with the CHU-9D. One-way and probabilistic sensitivity analyses were conducted to identify key drivers and quantify uncertainty. RESULTS: The preventive intervention was found to be highly cost-effective. The incremental cost per QALY gained was AU$3747. Probability of new caries and seeking treatment were identified as the main drivers of the model. In probabilistic sensitivity analysis intervention was cost effective in 100% of simulations. CONCLUSION: An annual preventive intervention for remote Indigenous communities in Australia is a highly cost-effective strategy to prevent dental caries and improve the quality of life of children.

Effect of family characteristics on periodontal diseases in children and adolescents-A systematic review.

AIM: To synthesize the literature on the influence of family/parents characteristics on periodontal diseases in children and adolescents. METHODS: An electronic search for relevant literature published between 2007 and 2017 was undertaken in PubMed, Embase, Cinahl and Cochrane databases; the search was updated in April 2018. Two reviewers independently reviewed the abstracts of these; of which, 43 articles were reviewed in full. RESULTS: Of the 746 retrieved titles, 649 remained after removing duplicates. Thirty articles met the inclusion criteria, and 13 were excluded. Also, two were included from the updated search. Data from the reviewed articles indicate that all three indicators of parent's socioeconomic status (income, education and occupation) are significantly associated with periodontal diseases in children. Better periodontal status was observed in children of parents with higher SES than those whose parents were of lower SES. Although the association between parent's smoking practices, level of periodontal diseases and children's periodontal status was explored only in few studies, findings indicate that children exposed to passive smoking and having parents with periodontal diseases are more likely to present with periodontal diseases as well. CONCLUSIONS: Most of the studies considered socioeconomic factors and had not attempted to explore the impact of parental psychosocial variables on periodontal diseases in children. The literature indicates that these variables significantly influence health practices, including oral hygiene practices, which could ultimately affect periodontal health. More studies are required to explore the association of these variables with periodontal outcomes in children.

Validation of Persian rapid estimate of adult literacy in dentistry.

AIM: The aim of the present study was to establish the psychometric properties of the Rapid Estimate of adult Literacy in Dentistry-99 (REALD-99) in the Persian language for use in an Iranian population (IREALD-99). METHODS: A total of 421 participants with a mean age of 28 years (59% male) were included in the study. Participants included those who were 18 years or older and those residing in Quazvin (a city close to Tehran), Iran. A forward-backward translation process was used for the IREALD-99. The Test of Functional Health Literacy in Dentistry (TOFHLiD) was also administrated. The validity of the IREALD-99 was investigated by comparing the IREALD-99 across the categories of education and income levels. To further investigate, the correlation of IREALD-99 with TOFHLiD was computed. A principal component analysis (PCA) was performed on the data to assess unidimensionality and strong first factor. The Rasch mathematical model was used to evaluate the contribution of each item to the overall measure, and whether the data were invariant to differences in sex. Reliability was estimated with Cronbach's α and test-retest correlation. RESULTS: Cronbach's alpha for the IREALD-99 was 0.98, indicating strong internal consistency. The test-retest correlation was 0.97. IREALD-99 scores differed by education levels. IREALD-99 scores were positively related to TOFHLiD scores (rh = 0.72, P < 0.01). In addition, IREALD-99 showed positive correlation with self-rated oral health status (rh = 0.31, P < 0.01) as evidence of convergent validity. The PCA indicated a strong first component, five times the strength of the second component and nine times the third. The empirical data were a close fit with the Rasch mathematical model. There was not a significant difference in scores with respect to income level (P = 0.09), and only the very lowest income level was significantly different (P < 0.01). CONCLUSIONS: The IREALD-99 exhibited excellent reliability on repeated administrations, as well as internal consistency. The IREALD-99 can be used for the basic screening of oral health literacy among the Iranian population.