Development of the oral resistome during the first decade of life.

Antibiotic overuse has promoted the spread of antimicrobial resistance (AMR) with significant health and economic consequences. Genome sequencing reveals the widespread presence of antimicrobial resistance genes (ARGs) in diverse microbial environments. Hence, surveillance of resistance reservoirs, like the rarely explored oral microbiome, is necessary to combat AMR. Here, we characterise the development of the paediatric oral resistome and investigate its role in dental caries in 221 twin children (124 females and 97 males) sampled at three time points over the first decade of life. From 530 oral metagenomes, we identify 309 ARGs, which significantly cluster by age, with host genetic effects detected from infancy onwards. Our results suggest potential mobilisation of ARGs increases with age as the AMR associated mobile genetic element, Tn916 transposase was co-located with more species and ARGs in older children. We find a depletion of ARGs and species in dental caries compared to health. This trend reverses in restored teeth. Here we show the paediatric oral resistome is an inherent and dynamic component of the oral microbiome, with a potential role in transmission of AMR and dysbiosis.

Dental education in the time of SARS-CoV-2.

INTRODUCTION: The SARS-CoV-2 virus has forced profound change on all aspects of society, with significant impact on dental education. Dental students like all other dental clinical personnel are considered to be at the highest risk amongst healthcare workers due to the nature of treatment, namely, working in the oral cavity (known reservoir for the virus) and the routine use of aerosol-generating procedures. The nature of this pandemic has created several challenges to dental clinical education. The aim of this paper is to discuss these challenges and how educators have sought to overcome them. MATERIALS AND METHODS: This paper reviews the evidence base around bio-aerosol and infection control measures specifically in the context of dental education. RESULTS: Using current knowledge of bio-aerosol and increasing understanding of the virus, dental educators can implement evidence-based measures to ensure safe teaching within both simulation and clinical environments. DISCUSSION: This paper contextualises the current pandemic in a dental education setting by providing a critical appraisal of the challenges posed by SARS-CoV-2 and how these challenges may be managed. CONCLUSION: The SARS-CoV-2 pandemic has created unique challenges for dental schools worldwide. Dental educators have sought to identify these challenges and find solutions appropriate to the stage of the pandemic specific to their geographical location.

Location of prosthodontic treatment and oral health-related quality of life--an exploratory study.

PURPOSE: Prosthodontic treatment has a positive effect on oral health-related quality of life (OHRQoL); however, there is a paucity of studies assessing the impact of OHRQoL based on where in the mouth ("location") the treatment is performed. This exploratory study investigated the association of the location (anterior, posterior region) of prosthodontic treatment with magnitude and nature of OHRQoL changes. METHODS: In this non-randomized prospective clinical study, 190 adult patients (17-83 years) were recruited at baseline and 104 were available for the follow-up analyses. Of those, 50 patients received treatment only in the posterior segment and 54 patients in both anterior and posterior regions. Treatment included conventional fixed partial prostheses, removable prostheses or a combination of both. OHRQoL was assessed with the German language version of the 49-item Oral Health Impact Profile (OHIP) at baseline and the questionnaire was repeated 4-6 weeks post-treatment. Magnitude and effect size of changes in summary and sub-scale scores were calculated and data analyzed. RESULTS: Patients experienced a substantially impaired OHRQoL (mean OHIP score: 32.3 points) at baseline and an improvement in OHRQoL of 6.8 OHIP points following treatment. This study showed a greater improvement in OHRQoL in patients treated in both regions compared to those treated in the posterior region alone, especially in the function and aesthetic domains. CONCLUSIONS: This explorative study suggests that OHRQoL improvement is affected by where prosthodontic treatment is performed in the mouth. Greater understanding of qualitative aspects of reconstructive therapies is needed for improved treatment planning and patient consent.

Masking ability of bi- and tri- laminate all-ceramic veneers on tooth-colored ceramic discs.

STATEMENT: A predictable esthetic outcome is imperative when placing ceramic veneers. Discolored teeth pose a major challenge as sufficient material thickness is required to achieve a good esthetic result. There is limited evidence in the literature that compares the masking ability of multi-laminate veneers. PURPOSE: The aim of this in-vitro study was to compare the masking ability of bi-laminate (BL) and tri-laminate (TL) all-ceramic veneers cemented on tooth-colored ceramic discs. MATERIALS AND METHODS: A total of 40 veneers (shade A1, 10-mm diameter, 0.8-mm thick) were manufactured-20 BL veneers (0.4-mm pressable ceramic coping veneered with 0.4-mm thick enamel layer) and 20 TL veneers (0.4-mm coping veneered with 0.2-mm thick opaque interlayer and 0.2-mm thick enamel layer). A bonding apparatus was utilized to adhesively cement all veneers on the ceramic discs (shade A1), simulating teeth of light and dark color. The resulting groups (N = 10 each) were the reference groups (shade A1 ceramic base) BL-1 and TL-1 veneers, and the test groups (shade A4 ceramic base) BL-4 and TL-4 veneers. The color of the cemented veneers was measured using a spectrophotometer. The data were converted to CIE L*a*b* coordinates, and ΔE* were calculated to allow for statistical analysis. RESULTS: The color differences between the samples with the A1 and A4 ceramic bases were significantly lower when covered with TL veneers (mean ΔE*: 3.2 units) than with BL veneers (mean ΔE*: 4.0 units: p < 0.001), indicating a better masking ability of the TL veneers. CONCLUSION: The 0.8-mm thick TL veneer was able to mask darker tooth-colored ceramic disc within clinically acceptable limits. CLINICAL SIGNIFICANCE: Increased understanding of the masking ability of ceramics and of color science is necessary in these esthetically aware times. Providing tri-laminate veneers for darker colored teeth seems to result in more predictable esthetical results than when using bi-laminate veneers. Patients with discolored/darker teeth may benefit from a more predictable esthetic result when teeth restored with tri-laminate rather than bi-laminate veneers.