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 24 h 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.

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.

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.

Impact of dental treatment under general anesthesia on the oral health-related quality of life of adolescents and adults with special needs.

This study aimed to assess the perception of the family's primary caregiver on the oral health-related quality of life (OHRQoL), and the impact on family dynamics, of dental treatment under general anesthesia (GA) in adolescent and adult patients with intellectual and developmental disabilities (IDD) and neurocognitive disorders. Self-administered questionnaires were completed, before dental treatment, by 116 primary family caregivers of patients who received dental treatment under GA, and 102 (88%) of these caregivers completed the same questionnaires within 4 wk after treatment. The Child Oral Health Impact Profile (COHIP) and the Family Impact Scale (FIS) were shortened to a 14-item COHIP (COHIP-14) and a 12-item FIS (FIS-12) based on the limitations of patients' communication. The COHIP-14 and FIS-12 scores and each subscale improved after treatment. The baseline scores varied based on certain characteristics of the patients, such as age, disabilities, medications, caregivers, meal types, cooperation levels, and treatment needs. The postoperative improvement in OHRQoL was significant in the patients who were older than 30 yr of age, originally eating soft meals, displaying no or very low levels of cooperation, or receiving endodontic treatment. Based on the primary caregiver perceptions, the OHRQoL of adolescents and adults with IDD and neurocognitive disorders was improved by dental treatment under GA.

Does caries risk assessment predict the incidence of caries for special needs patients requiring general anesthesia?

OBJECTIVES: The aim of this study was to correlate the caries-related variables of special needs patients to the incidence of new caries. MATERIALS AND METHODS: Data for socio-demographic information and dental and general health status were obtained from 110 patients treated under general anesthesia because of their insufficient co-operation. The Cariogram program was used for risk assessment and other caries-related variables were also analyzed. Within a defined follow-up period (16.3 ± 9.5 months), 64 patients received dental examinations to assess newly developed caries. RESULTS: At baseline, the mean (SD) values of the DMFT (decayed, missing and filled teeth) and DT (decayed teeth) for the total patients were 9.2 (6.5) and 5.8 (5.3), respectively. During the follow-up period, new caries occurred in 48.4% of the patients and the mean value (SD) of the increased DMFT (iDMFT) was 2.1 (4.2). The patients with a higher increment of caries (iDMFT ≥3) showed significantly different caries risk profiles compared to the other patients (iDMFT <2) (p < 0.05). Close correlations existed between the caries increment and several caries-related variables; baseline DMFT, insufficient self-tooth-brushing and malocclusion were greatly associated with new caries development. CONCLUSIONS: Caries risk assessment could predict the incidence of future caries in hospital-based dentistry. Past caries experience and inadequate oral hygiene maintenance were largely related to caries development in special needs patients.

The color change in artificial white spot lesions measured using a spectroradiometer.

OBJECTIVES: The purpose of this study was to determine the color of white spot lesions. MATERIALS AND METHODS: Human premolars were subjected to a pH cycling to produce artificial caries lesions and classified into groups (n = 10/group): group 1, immersion in deionized water; group 2, pH cycling without fluoride (F) application; group 3, pH cycling with immersion in 1,000 ppm NaF solution; and group 4, pH cycling with immersion in 5,000 ppm NaF solution. CIE L*a*b* color parameters of the tooth were determined using a spectroradiometer at baseline, after demineralization and after pH cycling. The extent of demineralization was evaluated by scanning electron microscopy (SEM) and electron microprobe analysis (EPMA). RESULTS: Significant degrees of color change (ΔE*) were observed after demineralization (p < 0.05). The changes were mainly due to an increase in lightness (L*) and a decrease in yellowness (b*). F application induced a significantly large ΔE* in group 4 (p < 0.05). The color reversal after remineralization was mostly due to the recovery of L*. SEM and EPMA verified that net mineral gains occurred in the subsurface lesions. CONCLUSIONS: The initially white appearance of enamel caries was a result of changes of L* and b*. F treatment partially restored the color of white spot lesions. CLINICAL RELEVANCE: F-driven remineralization induced both mineral gains and esthetic enhancement of artificially produced enamel white spot lesions. The increase of L* and the decrease of b* contributed to the color changes.

Caries risk profiles of Korean dental patients using simplified Cariogram models.

OBJECTIVES: The objective of this study was to compare the caries risk profiles obtained from the simplified Cariogram models and the conventional Cariogram model of Korean dental patients. MATERIALS AND METHODS: Data required for a caries risk assessment with the Cariogram were collected from 80 young adult patients (mean: 23 years old). Three different simplified Cariogram models were produced with exclusion of either or both salivary secretion rate and lactobacilli count: group 1, conventional model; group 2, both salivary secretion rate and lactobacilli count excluded; group 3, salivary secretion rate excluded; group 4, lactobacilli count excluded. RESULTS: The mean chance of avoiding caries in group 1 (55.5%) was not significantly different from those in groups 2 and 3. Also four caries-related sectors of the Cariogram (diet, bacteria, susceptibility and circumstance) in group 1 were not significantly different than in groups 2 and 3. Group 4 showed significant differences from group 1 in the mean chance of avoiding caries and the diet, susceptibility and circumstance sectors (p < 0.05). Significant correlations were detected between all risk factors and their corresponding risk sectors (p < 0.05). Also there were significant correlations between each risk factor and the chance of avoiding caries, except for the amount of plaque, in groups 1, 2 and 3 (p < 0.05). CONCLUSIONS: The simplified Cariogram model without salivary secretion rate and lactobacilli count did not significantly change the outcome produced from the conventional model. However, single exclusion of lactobacilli count noticeably changed the caries risk profile.

Caries-preventive activity of fluoride-containing resin-based desensitizers.

OBJECTIVE: The purpose of this study was to evaluate the effects of different desensitizing agents on the prevention of root caries when applied to root surfaces. MATERIALS AND METHODS: Thirty human roots were sectioned into quarters with a 3 × 4 mm window. A desensitizer (VX, Clinpro™ XT Varnish; SP, Seal & Protect®; or PB, Clearfil™ Protect Bond) was applied to three of the quarters in each window. Teeth were stored separately in water for one day, 30 days, or 60 days. The remaining quarter, without the application of desensitizer, served as a control. After storage in water, all specimens were subjected to pH cycling. Scanning electron microscopy was used to observe the demineralization bands created on the subsurface layer. The weight percentages of fluorine (F), silica, and calcium (Ca) were determined using electron probe microanalysis to quantify the elemental distributions in the root dentin. The concentrations of F released during a pH cycling were measured. RESULTS: For the control group, the average lesion depth was 18.92 ± 5.42 µm, and the average Ca loss was 15.66% ± 6.80% in the superficial layer and 30.44% ± 9.61% in the subsurface layer. No Ca loss occurred in the desensitizer-treated groups. All desensitizing agents remained intact for at least 60 days. F levels were increased in the hybrid layer but not in the subhybrid area. Outward release of F diminished with time. CONCLUSION: The F-containing resin-based desensitizers protected exposed root surfaces from demineralization. F liberated from the desensitizers was detected only at minimal levels.

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

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: > 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 < .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 < .05). In the canals of moderate or severe curvature, EQ-S showed the highest removal percentage, followed by EndoActivator, Vibringe, and needle irrigation (p < .05). Light-coupled tracking showed the largest oscillating range in EQ-S (p < .05). CONCLUSIONS: Sonically activated irrigation systems with a flexible tip can be beneficial for calcium hydroxide intracanal dressing removal in the curved apical canals.

Can Caregiver Reports Reflect Dental Treatment Needs of Patients with Intellectual and Developmental Disabilities?

PURPOSE: This study aimed to obtain the oral health-related factors of patients with intellectual and developmental disabilities (IDD) from family caregivers and to relate caregiver-perceived risk factors to dental treatment needs of patients. MATERIALS AND METHODS: A total of 120 dyads of patients (mean [SD] age = 29.1 [8.4] years) and their family caregivers (mean [SD] age = 56.5 [9.5] years) were included. Data were obtained from self-administered questionnaires by caregivers and oral examinations by a dentist. Oral health conditions of patients were analysed in different age groups using paired t-tests. Caregiver-perceived oral health conditions of patients and dentist-assessed caries and periodontal disease were compared using Pearson's chi-squared and Fisher's exact tests. Relationships between patient factors and treatment needs were analysed using multiple logistic regression. RESULTS: Tooth pain, chewing difficulty, and reasons for the last dental visit were associated with high numbers of decayed teeth (DT) (p < 0.05). Overall oral health condition of patients rated by caregivers was related to high DT and the Community Periodontal Index (CPI) score (p < 0.05). Well-maintained dental care of caregivers was associated with lower numbers of DT and less urgent treatment needs of patients (p < 0.05). CONCLUSION: There were caregiver-perceived factors indicating dental treatment needs of patients with IDD. Proxy reports by caregivers can be used as risk predictors for ongoing dental problems of patients with communication limitations.

Information resources and material selection in bonded restorations among Korean dentists.

PURPOSE: To elucidate how dentists access knowledge sources when choosing adhesive agents for bonded restoration and whether these resources influenced the selection of materials. MATERIALS AND METHODS: A national survey was carried out involving dentists in South Korea. The questionnaire included the status of the operator, clinical techniques, and materials. A total of 12,193 e-mails were distributed, 2632 were opened by recipients, and 840 responses were collected. RESULTS: For primary information resources in material selection, 55.8% (n = 469) of the responders mentioned continuing education. This selection criteria varied according to the working status of the clinician (p < 0.0001). The choice of bonding system was influenced by of the length of the career (p < 0.0001), and the preferred bonding systems differed according to the source of the information (p = 0.035). CONCLUSION: The popular bonding systems were not ranked according to the bonding strategy, but a preference was found for specific brands or manufacturers. To decrease the confusion of clinicians related to the selection of bonding materials, evidence-based guidelines need to be comprehensibly organized and efficiently approached in clinics.

Periapical Healing in Single-visit Endodontics under General Anesthesia in Special Needs Patients.

INTRODUCTION: The aim of this study was to determine the prognostic factors of periapical healing of teeth after single-visit nonsurgical endodontic treatment under general anesthesia in special needs patients. METHODS: This retrospective study collected 448 teeth from 241 patients (mean age = 27.4 years, standard deviation = 13.9 years). A total of 271 teeth (60.5%) with clinical and radiographic follow-up records longer than 12 months (mean [standard deviation] = 56.1 [27.9]) were included in the outcome analysis. Demographic, systemic, and dental information about the cases were compared between the healed and nonhealed groups using the Pearson chi-square test. Factors contributing to periapical healing were determined with multivariate logistic regression analysis. RESULTS: Complete periapical healing without clinical signs was observed in 221 teeth (81.5%), uncertain healing with decreased size of the periapical lesion was shown in 43 teeth (15.9%), and no reduction in lesion size was observed in 7 cases (2.6%). In the multivariate analysis, diet type, oral hygiene maintenance, pulp vitality, and root filling length were detected as contributing factors for complete resolution of periapical lesions (P < .05). CONCLUSIONS: Successful outcomes of single-visit endodontic treatment under general anesthesia were shown in special needs patients. The prognoses were influenced by the clinical circumstances of the patients and the preoperative conditions of their teeth.

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 2mm 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 2min 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

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 microm, 19.3+/-0.73 microm and 18.4+/-0.63 microm, 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.

Influence of ceramic thickness and curing mode on the polymerization shrinkage kinetics of dual-cured resin cements.

OBJECTIVES: The purpose of this study was to assess how ceramic disc thickness and curing mode (light or chemical) affects the polymerization shrinkage of dual-cured resin cements and to evaluate the effect of the ceramic discs on the curing speed of the cements during light exposure. METHODS: Six commercial resin cements, RelyX ARC, Bistite II, Duolink, Panavia F, Variolink II and Choice were used. Filler weight contents were determined by the ash method. Four ceramic discs with thicknesses of 0.5, 1, 2 and 4mm, respectively, were made. The attenuation of light intensity due to the ceramic discs was measured using a radiometer. The polymerization shrinkage kinetics of the resin cements by chemical or light cure through the different ceramic discs was measured using a bonded-disc method. RESULTS: There were differences in filler content among brands of resin cement. The polymerization shrinkage without ceramic disc was 2.61-4.59% by chemical cure and 2.93-4.66% by light cure. The polymerization shrinkage of RelyX ARC and Panavia F by chemical cure was statistically lower than by light cure (p<0.05). Polymerization shrinkage and filler weight were inversely related (R=-0.965). Both the transmitted light intensity and polymerization shrinkage decreased with increasing thickness of ceramic discs (p<0.05). The time to reach the maximum shrinkage rate of the resin cements increased with increasing ceramic thickness. The cure speed by light cure was 15-322 times faster than by chemical cure. SIGNIFICANCE: The polymerization shrinkage kinetics of dual-cured resin cements significantly differed between brands under various curing conditions. Clinicians should be aware of the setting characteristics of the cements, so they can choose the optimal materials for different clinical situations.

Analysis of the effect of oral midazolam and triazolam premedication before general anesthesia in patients with disabilities with difficulty in cooperation.

BACKGROUND: When performing dental treatment under general anesthesia in adult patients who have difficulty cooperating due to intellectual disabilities, anesthesia induction may be difficult as well. In particular, patients who refuse to come into the dental office or sit in the dental chair may have to be forced to do so. However, for adult patients with a large physique, physical restraint may be difficult, while oral sedatives as premedication may be helpful. Here, a retrospective analysis was performed to investigate the effect of oral sedatives. METHODS: A hospital-based medical information database was searched for patients who were prescribed oral midazolam or triazolam between January 2009 and December 2017. Pre-anesthesia evaluation, anesthesia, and anesthesia recovery records of all patients were analyzed, and information on disability type, reason for prescribing oral sedatives, prescribed medication and dose, cooperation level during anesthesia induction, anesthesia duration, length of recovery room stay, and complications was retrieved. RESULTS: A total of 97 patients were identified, of whom 50 and 47 received midazolam and triazolam, respectively. The major types of disability were intellectual disabilities, autism, Down syndrome, blindness, cerebral palsy, and epilepsy. Analyses of changes in cooperation levels after drug administration showed that anesthesia induction without physical restraint was possible in 56.0% of patients in the midazolam group and in 46.8% of patients in the triazolam group (P = 0.312). CONCLUSIONS: With administration of oral midazolam or triazolam, general anesthesia induction without any physical restraint was possible in approximately 50% of patients, with no difference between the drugs.

Influence of instrument compliance and specimen thickness on the polymerization shrinkage stress measurement of light-cured composites.

OBJECTIVES: The aim of our study was to investigate the effects of instrument compliance and specimen geometry on the polymerization shrinkage stress measurements of composites. METHODS: A custom designed stress-strain analyzer was made using a linear variable differential transformer probe and a cantilever load cell. A sandblasted glass rod was fixed at the free end of the load cell, and another glass rod was located on a base plate. A composite was placed between the two rods and light cured. The end displacement of the load cell during polymerization was recorded for 10 min. A flowable (Filtek Flow), a universal hybrid (Z100), and a packable (P60) composite were studied. To investigate the effect of specimen geometry and instrument compliance, specimen thickness was varied between 0.5, 1.0, and 2.0 mm, and three load cells with maximum capacities of 20, 100, and 500kgf were used. Ten maxillary premolars were prepared with two sizes of MOD cavities; the bucco-lingual widths and depths of the cavities were 1.5 mm x 2 mm and 3 mm x 2 mm, and the cusp compliance and deflection were measured before and during composite polymerization. RESULTS: The measured polymerization stress decreased in the order of Filtek Flow, Z100, and P60 for all measurement conditions. As the specimen thickness was increased, the shrinkage stress per unit thickness (mm) decreased. The measured stress decreased with increasing instrument compliance. The cusp compliance (3.32 microm/N) of the 3 mm x 2 mm cavities was similar to that of instrument with a 20 kgf load cell (3.34 microm/N). SIGNIFICANCE: For determining the most clinically relevant values for shrinkage stress of dental composites, the instrument compliance should closely match that of the tooth walls in the cavity geometry to be tested.

A retrospective analysis of outpatient anesthesia management for dental treatment of patients with severe Alzheimer's disease.

BACKGROUND: The number of patients with Alzheimer's disease is growing worldwide, and the proportion of patients requiring dental treatment under general anesthesia increases with increasing severity of the disease. However, outpatient anesthesia management for these patients involves great risks, as most patients with Alzheimer's disease are old and may show reduced cardiopulmonary functions and have cognitive disorders. METHODS: This study retrospectively investigated 43 patients with Alzheimer's disease who received outpatient anesthesia for dental treatment between 2012-2017. Pre-anesthesia patient evaluation, dental treatment details, anesthetics dose, blood pressure, duration and procedure of anesthesia, and post-recovery management were analyzed and compared between patients who underwent general anesthesia or intravenous sedation. RESULTS: Mean age of patients was about 70 years; mean duration of Alzheimer's disease since diagnosis was 6.3 years. Severity was assessed using the global deterioration scale; 62.8% of patients were in level ≥ 6. Mean duration of anesthesia was 178 minutes for general anesthesia and 85 minutes for intravenous sedation. Mean recovery time was 65 minutes. Eleven patients underwent intravenous sedation using propofol, and 22/32 cases involved total intravenous anesthesia using propofol and remifentanil. Anesthesia was maintained with desflurane for other patients. While maintaining anesthesia, inotropic and atropine were used for eight and four patients, respectively. No patient developed postoperative delirium. All patients were discharged without complications. CONCLUSION: With appropriate anesthetic management, outpatient anesthesia was successfully performed without complications for dental treatment for patients with severe Alzheimer's disease.

Quantitative comparison of the water permeable zone among four types of dental adhesives used with a dual-cured composite.

This study compared silver penetration in the adhesive interface among four versions of adhesives from the same manufacturer: OptiBond FL, OptiBond Solo Plus, OptiBond Solo Plus Dual Cure, and OptiBond Solo Plus Self-Etch, when coupled with dual-cured composite, CoreRestore 2 (Kerr). Twenty flat dentin surfaces were prepared using one of the adhesives and bonded with the composite, following the manufacturer's instructions. The surfaces were sectioned into 2-mm slabs and immersed in ammoniacal silver nitrate for 24 hours. Each specimen was exposed to a photodeveloping solution for eight hours and examined with a scanning electron microscope (SEM). The water permeable area occupied by the silver nitrate tracer was determined, and the relative weight of silver was analyzed by wavelength dispersive spectrometry (WDS). The OptiBond FL group had a significantly lower silver content than the other groups (p < 0.0001). Each group demonstrated different patterns of silver deposition within the adhesive layer and within various features of artifactual fracture from dehydration stress of the SEM. This may be indicative of weak links in the bonded interfaces. Simplified-step adhesives showed increased permeability, which can lead to disruption of coupling with composites.

Elemental analysis of caries-affected root dentin and artificially demineralized dentin.

OBJECTIVES: This study aimed to analyze the mineral composition of naturally- and artificially-produced caries-affected root dentin and to determine the elemental incorporation of resin-modified glass ionomer (RMGI) into the demineralized dentin. MATERIALS AND METHODS: Box-formed cavities were prepared on buccal and lingual root surfaces of sound human premolars (n = 15). One cavity was exposed to a microbial caries model using a strain of Streptococcus mutans. The other cavity was subjected to a chemical model under pH cycling. Premolars and molars with root surface caries were used as a natural caries model (n = 15). Outer caries lesion was removed using a carbide bur and a hand excavator under a dyeing technique and restored with RMGI (FujiII LC, GC Corp.). The weight percentages of calcium (Ca), phosphate (P), and strontium (Sr) and the widths of demineralized dentin were determined by electron probe microanalysis and compared among the groups using ANOVA and Tukey test (p < 0.05). RESULTS: There was a pattern of demineralization in all models, as visualized with scanning electron microscopy. Artificial models induced greater losses of Ca and P and larger widths of demineralized dentin than did a natural caries model (p < 0.05). Sr was diffused into the demineralized dentin layer from RMGI. CONCLUSIONS: Both microbial and chemical caries models produced similar patterns of mineral composition on the caries-affected dentin. However, the artificial lesions had a relatively larger extent of demineralization than did the natural lesions. RMGI was incorporated into the superficial layer of the caries-affected dentin.