Oral health issues of young adults with severe intellectual and developmental disabilities and caregiver burdens: a qualitative study

Background Oral health maintenance is difficult to be achieved alone by patients with special needs and insufficient self-care skills. This study aims to investigate how the oral health issues of young adults with severe intellectual and developmental disabilities (IDD) affect caregiver burdens. Methods A qualitative research method was employed with semi-structured interviews conducted with 14 maternal caregivers of patients with severe IDD. Eleven young adults had neurofunctional disorders and three had autism spectrum disorders. All recorded data were transcribed verbatim and subjected to thematic analysis. Results Three themes emerged from the main agenda: predisposing oral dysfunction, home care challenges, and professional treatment barriers. The severity of the disabilities had an impact on oral disease risks that increased as patients aged. Participants indicated that, among the daily living activities of their patients, toothbrushing was a particular hardship due to their dysphagia and behavioral issues. Factors impacting on dental treatment indicated by caregivers included social, emotional, and financial circumstances. Conclusions Dysphagia and behavioral issues of adult patients with severe IDD contributed to caregiver burdens in the dental care of the patients. Caregiver burdens and barriers to treatment were mutual factors hindering adequate interventions in dealing with dental problems of the patients.The work was supported from the Grant of National Research Foundation funded by the Korea Ministry of Science and ICT (NRF No.2018003847)

Impact of endodontic case difficulty on operating time of single visit nonsurgical endodontic treatment under general anesthesia

Background A Case Difficulty Assessment Form was designed for use in endodontic curricula, and to assist practitioners with treatment planning, referral and recording. The aim of this study was to determine how endodontic case difficulty factors influence the operating time of single-visit nonsurgical endodontic treatments under general anesthesia. Methods Data on 198 single-visit endodontic treatments (80 anterior teeth, 43 premolars, and 75 molars) performed under general anesthesia by a specialized practitioner were obtained from 119 special needs patients (mean [SD] age = 30.7 [14.7] years). Total duration of operation was analyzed with relation to demographic and dental factors and American Association of Endodontists (AAE) Case Difficulty Assessment factors. Mann–Whitney U test, t-test, and Kruskal–Wallis test were used to assess relationships between operating time and confounding factors (p < 0.05). Results High difficulty cases required significantly longer time to complete operations than treatments of minimal-to-moderate difficulty regardless of tooth type (p < 0.05). Demographic factors of the patients rarely influenced operating time length. Among variables included in the AAE Case Difficulty Assessment Form, tooth position, crown morphology, root morphology, canal appearance, and periodontal condition were significantly associated with increased operating time (p < 0.05). Conclusions A higher level of case difficulty contributed to increased duration of endodontic treatment under general anesthesia indicating that Endodontic Case Difficulty Assessment Form is useful for predicting the duration of nonsurgical endodontic treatment. Among many factors, complicated anatomic features of the treated teeth increased case complexity and extended operating time.This research received support from the grant of National Research Foundation funded by the Korea Ministry of Science and ICT (NRF No. 2018003847)

Cytotoxicity and reactive oxygen species production induced by different co-monomer eluted from nanohybrid dental composites

Background Safety issues for dental restorative composites are critical to material selection, but, limited information is available to dental practitioners. This study aimed to compare the chemical and biological characteristics of three nanohybrid dental composites by assessing filler particle analysis, monomer degree of conversion (DC), the composition of eluates, and cytotoxicity and reactive oxygen species (ROS) production in fibroblasts. Methods Three nanohybrid composites (TN, Tetric N-Ceram; CX, Ceram X Sphere Tec One; and DN, DenFil NX) were used. The size distribution and morphology of the filler particles were analysed using scanning electron microscopy (n = 5). The DC was measured via micro-Raman spectroscopy (n = 5). For the component analysis, methanol eluates from the light-polymerised composites were evaluated by gas chromatography/mass spectrometry (n = 3). The eluates were prepared from the polymerised composites after 24h in a cell culture medium. A live/dead assay (n = 9) and Water-Soluble Tetrazolium-1 assay (n = 9) were performed and compared with negative and positive controls. The ROS in composites were compared with NC. Statistical significance in differences was assessed using a t-test and ANOVA (α = 0.05). Results Morphological variations in different-sized fillers were observed in the composites. The DC values were not significantly different among the composites. The amounts of 2-hydroxyethyl methacrylate (HEMA) were higher in TN than DN (p = 0.0022) and triethylene glycol dimethacrylate (TEGDMA) in CX was higher than in others (p < 0.0001). The lowest cell viability was shown in CX (p < 0.0001) and the highest ROS formation was detected in TN (p < 0.0001). Conclusions Three nanohybrid dental composites exhibited various compositions of filler sizes and resin components, resulting in different levels of cytotoxicity and ROS production. Chemical compositions of dental composites can be considered with their biological impact on safety issues in the intraoral use of dental restorative composites. CX with the highest TEGDMA showed the highest cytotoxicity induced by ROS accumulation. DN with lower TEGDMA and HEMA presented the highest cell viability.This work was supported by the Korea Medical Device Development Fund grant funded by the Korea government (the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, the Ministry of Health & Wel‑fare, the Ministry of Food and Drug Safety) (Project Number: 9991006717, KMDF_PR_20200901_0044)

Sonic irrigation for removal of calcium hydroxide in the apical root canal: A micro-CT and light-coupled tracking analysis

© 2022 Moon et al.Objective This study aimed to evaluate the efficacy of three sonic irrigation systems for removal of calcium hydroxide dressing from the apical root canal. Materials and methods A total of 96 single-rooted teeth in three categories of root canal curvatures (straight: 0–5◦, moderate: 6–20◦, and severe: &gt; 20◦) were allocated to four groups: conventional needle irrigation, EndoActivator, EQ-S, and Vibringe. The root canals were instrumented using Protaper NEXT and filled with calcium hydroxide. After removal of calcium hydroxide, the remaining volume of calcium hydroxide was measured by micro-CT analysis. Data were compared among root canal curvatures and irrigation systems using the Kruskal-Wallis test and Mann-Whitney test (p &lt; .05). The oscillating range of each irrigation system was measured using light-coupled motion tracking. Results The volumes of calcium hydroxide remaining in the canals with severe curvature were significantly higher than in those of straight curvature (p &lt; .05). In the canals of moderate or severe curvature, EQ-S showed the highest removal percentage, followed by EndoActivator, Vibringe, and needle irrigation (p &lt; .05). Light-coupled tracking showed the largest oscillating range in EQ-S (p &lt; .05). Conclusions Sonically activated irrigation systems with a flexible tip can be beneficial for calcium hydroxide intracanal dressing removal in the curved apical canals.N

Slumping resistance and viscoelasticity prior to setting of dental composites

Objectives: The aim of this study was to develop a method for measuring the slumping resistance of resin composites and to evaluate the efficacy using rheological methodology. Methods. Two commercial hybrid composites (Z100 and Z250) and a nanofill composite (Z350) were used to make disc-shaped specimens of 2 mm thickness. Three kinds of aluminum molds with triangular, circular, and square shaped cutting surfaces were pressed onto the resin discs to make standardized imprints. The imprints were light-cured either immediately (non-slumped) or after waiting for 2 min at 25 degrees C (slumped). White stone replicas were made and then scanned for topography using a laser 3-D profilometer. Slumping resistance index (SRI) was defined as the ratio of the groove depth of the slumped specimen to that of the non-slumped specimen. The pre-cure viscoelasticity of each composite was evaluated by an oscillatory shear test and normal stress was measured by a squeeze test using a rheometer. Correlation analysis was performed to investigate the relationship between the viscoelastic properties and SRI. Results. SRI varied between the three materials (Z100 < Z250 < Z350) and the imprint shapes did not affect the slumping tendency The SRI was strongly correlated with the loss shear modulus G `` but not with the loss tangent. Also, slumping resistance was more closely related to the resistance to shear flow than to the normal stress. Significance. Slumping tendency could be quantified using the imprint method and SRI. The index may be applicable to evaluate the clinical handling characteristics of composites. (C) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Color and hardness changes in artificial white spot lesions after resin infiltration

Objectives The purpose of this study was to determine the effect of resin infiltration technique on color and surface hardness of white spot lesion (WSL) with various degrees of demineralization. Materials and Methods Ten human upper premolars were cut and divided into quarters with a 3 × 4 mm window on the enamel surface. Each specimens were separated into four groups (n = 10) and immersed in demineralization solution to create WSL: control, no treatment (baseline); 12 h, 12 hr demineralization; 24 h, 24 hr demineralization; 48 h, 48 hr demineralization. Resin infiltration was performed to the specimens using Icon (DMG). CIEL*a*b* color parameters of the enamel-dentin complex were determined using a spectroradiometer at baseline, after caries formation and after resin infiltration. Surface hardness was measured by Vickers Micro Hardness Tester (Shimadzu, HMV-2). The differences in color and hardness among the groups were analyzed with ANOVA followed by Tukey test. Results Resin infiltration induced color changes and increased the hardness of demineralized enamel. After resin infiltration, there was no difference in color change (ΔE*) or microhardness among the groups (p < 0.05). Conclusion There was no difference in the effect of resin infiltration on color and hardness among groups with different extents of demineralization

Effects of matrix metallproteinases on dentin bonding and strategies to increase durability of dentin adhesion

The limited durability of resin-dentin bonds severely compromises the longevity of composite resin restorations. Resin-dentin bond degradation might occur via degradation of water-rich and resin sparse collagen matrices by host-derived matrix metalloproteinases (MMPs). This review article provides overview of current knowledge of the role of MMPs in dentin matrix degradation and four experimental strategies for extending the longevity of resin-dentin bonds. They include: (1) the use of broad-spectrum inhibitors of MMPs, (2) the use of cross-linking agents for silencing the activities of MMPs, (3) ethanol wet-bonding with hydrophobic resin, (4) biomimetic remineralization of water-filled collagen matrix. A combination of these strategies will be able to overcome the limitations in resin-dentin adhesion

Flexural strength and microstructure of two lithium disilicate glass ceramics for CAD/CAM restoration in the dental clinic

Objectives There has been a growing interest in glass ceramic systems with good esthetics, high fracture resistance and bonding durability, and simplified fabrication techniques using CAD/CAM. The aim of this study is to compare flexural strength before and after heat treatment of two lithium disilicate CAD/CAM blocks, IPS e.max CAD (Ivoclar Vivadent) and Rosetta SM (Hass), and to observe their crystalline structures. Materials and Methods Biaxial flexural strength was tested according to ISO 6872 with 20 disc form specimens sliced from each block before and after heat treatment. Also, the crystalline structures were observed using field-emission scanning microscopy (FE-SEM, Hitachi) and x-ray diffraction (XRD, Rigaku) analysis. The mean values of the biaxial flexural strength were analyzed by the Mann-Whitney U test at a significance level of p = 0.05. Results There were no statistically significant differences in flexural strength between IPS e.max CAD and Rosetta SM either before heat treatment or after heat treatment. For both ceramics, the initial flexural strength greatly increased after heat treatment, with significant differences (p < 0.05). The FE-SEM images presented similar patterns of crystalline structure in the two ceramics. In the XRD analysis, they also had similar patterns, presenting high peak positions corresponding to the standard lithium metasilicate and lithium disilicate at each stage of heat treatment. Conclusions IPS e.max CAD and Rosetta SM showed no significant differences in flexural strength. They had a similar crystalline pattern and molecular composition

How should composite be layered to reduce shrinkage stress: Incremental or bulk filling?

Objectives. The purpose of this study was to determine the effect of different layering techniques on cuspal deflection in direct composite restorations. Methods. Aluminum blocks were used to prepare MOD cavities divided into three groups. Each cavity was restored with composite using three different filling techniques. Group 1 was filled in bulk, group 2 was restored by a horizontal increment technique, and group 3 by an oblique increment technique. Cuspal deflection was measured with LVDT probes and compared among groups using ANOVA and Scheffe`s post hoc test (alpha = 0.05). Results. The cuspal deflections in groups 1-3 were 21.6 +/- 0.90 mu m, 19.3 +/- 0.73 mu m and 18.4 +/- 0.63 mu m, respectively. The bulk filling technique yielded significantly more cuspal deflection than the incremental filling techniques, while there was no significant difference between the horizontal and oblique increment methods. Significance. Cuspal deflection resulting from polymerization shrinkage can be reduced by incremental filling techniques to obtain optimal outcomes in clinical situations. (C) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.1

Bonding of the silane containing multi-mode universal adhesive for lithium disilicate ceramics

Objectives This study evaluated the influence of a multi-mode universal adhesive (MUA) containing silane (Single Bond Universal, 3M EPSE) on the bonding of resin cement to lithium disilicate. Materials and Methods Thirty IPS e.max CAD specimens (Ivoclar Vivadent) were fabricated. The surfaces were treated as follows: Group A, adhesive that did not contain silane (ANS, Porcelain Bonding Resin, Bisco); Group B, silane (S) and ANS; Group C, hydrofluoric acid (HF), S, and ANS; Group D, MUA; Group E, HF and MUA. Dual-cure resin cement (NX3, Kerr) was applied and composite resin cylinders of 0.8 mm in diameter were placed on it before light polymerization. Bonded specimens were stored in water for 24 hours or underwent a 10,000 thermocycling process prior to microshear bond strength testing. The data were analyzed using multivariate analysis of variance (p < 0.05). Results Bond strength varied significantly among the groups (p < 0.05), except for Groups A and D. Group C showed the highest initial bond strength (27.1 ± 6.9 MPa), followed by Group E, Group B, Group D, and Group A. Thermocycling significantly reduced bond strength in Groups B, C, and E (p < 0.05). Bond strength in Group C was the highest regardless of the storage conditions (p < 0.05). Conclusions Surface treatment of lithium disilicate using HF and silane increased the bond strength of resin cement. However, after thermocycling, the silane in MUA did not help achieve durable bond strength between lithium disilicate and resin cement, even when HF was applied