Journal of oral science最新文献

Purpose: Apically extruded debris, canal transportation and shaping ability were compared between contracted endodontic cavities (CECs) and traditional endodontic cavities (TECs) after instrumentation with XP-endo Shaper (XPS), ProTaper Gold (PTG), ProTaper for hand-use (HPT) and Hero Shaper.

Methods: The CECs or TECs groups were sub-divided into 24 groups according to root canal morphology and nickel-titanium (Ni-Ti) instruments. The weight of apically extruded debris was calculated using the Myers and Montgomery model. Pre- and postoperative images of teeth were scanned using micro-CT and the three-dimensional models were constructed and compared.

Results: Under CECs or TECs, XPS and PTG produced less apical debris and formed less canal transportation than HPT and Hero Shaper (P < 0.05). XPS group under CECs extruded less apical debris than that under TCEs for round canals with curvature of 20°-35° (P < 0.05). The centering ratios of four tested instruments were higher under TECs than those under CECs (P < 0.05). The HPT and Hero Shaper had more transportation under CECs than that under TCEs (P < 0.05). No statistical difference was found regarding shaping ability among all the groups.

Conclusion: Under CECs, XPS preserves the original root canal anatomy, meanwhile it produces less apical debris than the other instruments.

Purpose: To evaluate the color match of single-shade resin composites before and after bleaching procedures, through instrumental and visual analyses.

Methods: Class V cavities were created on the buccal surfaces of 80 extracted human molars, restored with 4 single-shade composites (Omnichroma; Clearfil Majesty ES-2 Universal; Essentia Universal; Venus Diamond One). A spectrophotometer (VITA Easyshade V) was used to evaluate the tooth/resin color match before (T₀), and 24 h (T₁) and one week (T₂) after dental bleaching (Opalescence Boost PF 40%). Color variations (ΔE₀₀) were calculated and statistically analyzed (P < 0.05). Visual analysis was performed before and after tooth bleaching.

Results: Spectrophotometric evaluations revealed statistically significant differences between materials at T₀, T₁, and T₂ (P < 0.05). Visual analysis reported excellent and very good grades (0 and 1, respectively), irrespective of the materials and timepoints.

Conclusion: Data seem to indicate that single shade composites are able to shift their color when the surrounding tooth undergoes bleaching effects. Single-shade composites seem to achieve a good color match with the surrounding tooth structure, before and after professional bleaching.

Purpose: To assess the prevalence and distribution of pulp stones in a Saudi population.

Methods: A cone beam computed tomography (CBCT) analysis of 150 upper and 150 lower dental arches was performed. The relationships between pulp stones and age, sex, tooth type, dental arch, orthodontic treatment, caries, and restoration were statistically examined (P < 0.05).

Results: A total of 295 dental arches (98.3%) had at least one pulp stone, and the prevalence was higher in the maxillary teeth (56.2%) than in the mandibular teeth (48.1%) (P = 0.0003). Men were more likely to have pulp stones than women (P = 0.011 for the maxilla, P < 0.0001 for the mandible). Furthermore, age and orthodontic treatment had no significant effects on the incidence of pulp stones (P > 0.05). A higher occurrence of pulp stones was observed in the first molars (>91%), and in carious and restored teeth when compared to intact teeth (P < 0.05).

Conclusion: Pulp stones were more prevalent in the upper dental arches, first molars, and carious and restored teeth, as well as in the male population, and were not associated with age or orthodontic treatment.

Purpose: The purpose of this in vivo study was to determine the effects of stress-induced depression and antidepressants on depressive-like behavior, microstructure, and histomorphology of the temporomandibular joint (TMJ) using rats.

Methods: Experimentally induced depression in rats was created before being treated with two antidepressants; escitalopram (selective-serotonin-reuptake inhibitors) and atomoxetine (norepinephrine-reuptake inhibitors). Micro-computed tomography (Micro-CT) was performed to measure the change in bone volume and bone porosity of the condyle. Further histological evaluation of the condylar cartilage was performed.

Results: Micro-CT scanning revealed a decrease in bone volume in the depression group. The bone porosity percentage significantly increased in both the escitalopram and atomoxetine groups compared with the control group and the depression group. Histopathological analysis showed increased thickness of cartilage layers in the depression group. In the atomoxetine group, there was a significant increase in the pre-hypertrophic and hypertrophic layer thickness and cell count, but a significant decrease in proteoglycans.

Conclusion: The present study findings indicated the change in TMJ characteristics, especially on the superficial part of the condylar head in the depression group. Concerning the applicability of the different antidepressants, depression with the treatment of atomoxetine has the most disadvantages due to bone porosity and cartilaginous condyle changes.

Purpose: To evaluate the marginal integrity of various pit and fissure sealants subjected to different application methods.

Methods: A total of 253 non-carious human third molars extracted and randomly divided into two groups according to the preparation method employed: invasive or non-invasive. Eight fissure sealant materials were tested: nano-filled flowable composite (Filtek Ultimate Flow), nanohybrid flowable composite (GrandioSo Flow), micro-hybrid flowable composite (Majesty Flow), resin-based unfilled fissure sealant (ClinPro Sealant), resin-based filled fissure sealant (Fissurit FX), resin-based highly filled fissure sealant (GrandioSeal), giomer-based fissure sealant (BeautiSealant), and glass ionomer-based fissure sealant (Fuji Triage). Samples were subjected to two-year cyclic thermo-mechanical and brushing simulations. Two observers quantitatively evaluated the restoration margins and classified them as either "permanent restoration edge", or if a gap larger than 250 μm was evident, "gapping at the restoration edge". The extent of the gap was recorded as a percentage relative to the total length of the restoration edge.

Results: The baseline marginal adaptation had no significant effect on the marginal adaptation (P > 0.05). However, the preparation method and type of fissure sealant material had a significant impact on the marginal adaptation (P < 0.05).

Conclusion: On the basis of quantitative analysis, the highest marginal integrity was observed for flowable composites, whereas the lowest was observed for glass ionomer-based fissure sealant.

Purpose: The aim of this study was to optimize the immunoresponsive and anti-Candida albicans (C. albicans) properties of guided bone regeneration-resorbable membranes (collagen) using additives based on synergistic mixtures of chlorhexidine with terpene-enriched fractions from Lippia alba essential oils (EO).

Methods: The anti-C. albicans activity of the fractions (individually or combined with chlorhexidine) was evaluated using planktonic and sessile cultures. J774A.1 murine macrophage cells were used to determine the cytotoxicity and immunoresponsive effects of the therapies.

Results: The anti-planktonic and anti-sessile performance of chlorhexidine on C. albicans was improved 2- to 4-fold by supplementation with citral-rich fractions. On macrophages, this fraction also exhibited a potentially cytoprotective action against the toxic effects of chlorhexidine, minimizing damage to the cell membrane, mitochondrial membrane potential, and nuclear integrity. Macrophages growing on collagen-membrane fragments and stimulated with the citral fraction (alone or with chlorhexidine) showed a significant increase in releasing the osteogenic cytokine TNF-α and enhancing the IL-4.

Conclusion: This combined therapy appears as a promising platform for the development of a prophylactic or therapeutic biocidal solution that can optimize the pharmacological characteristics of chlorhexidine (epithelium tolerance and anti-C. albicans consolidation on surfaces), as well as potentiating the immunoresponsive properties of collagen membranes.

Purpose: To compare the effects of gels containing 2.5% and 5% carboxymethyl chitosan amorphous calcium phosphate (CMC-ACP) on the microhardness of primary tooth enamel.

Methods: Twenty-four tooth specimens were demineralized with 37% phosphoric acid and divided into four groups: an untreated control group, a positive control group treated with casein phosphopeptide amorphous calcium phosphate, and two groups treated with 2.5% and 5% CMC-ACP gel, respectively. The enamel surface hardness was then measured with a Vickers hardness tester.

Results: In terms of Vickers Hardness Number (VHN), the degree of alteration in tooth surface microhardness was 77.83 ± 13.44 in the 5% CMC-ACP group and 52 ± 6.93 in the 2.5% CMC-ACP group (P = 0.002). The inter-group difference in the surface hardness change was significant (P < 0.05).

Conclusion: The 5% CMC-ACP gel increased the hardness of primary tooth enamel to a greater degree than the 2.5% CMC-ACP gel.

Purpose: This study examined the occlusion effect of a dentifrice containing stannous fluoride (SnF₂) and sodium fluoride (NaF) on periodontally involved teeth in comparison with healthy teeth using scanning electron microscopy (SEM) in comparison with a dentifrice containing NaF alone.

Methods: Sixty dentine samples obtained from single-rooted premolars, 15 of them extracted for orthodontic reasons (Group H) and 15 because of periodontal destruction (Group P), were included in the study. Each group of specimens was further divided into subgroups: HC and PC (control), H1 and P1 (treated with SnF₂ and NaF), and H2 and P2 (treated with NaF). The samples were brushed twice a day for 7 days, kept in artificial saliva, and examined by SEM. The diameters of open tubules and the numbers of tubules were assessed at ×2,000 magnification.

Results: The H and P groups showed similar diameters of open tubules. The numbers of open tubules in Groups H1, P1, H2, and P2 were significantly lower than in Groups HC and PC (P < 0.001), and consistent with the percentages of occluded tubules. Group P1 had the highest percentage of occluded tubules.

Conclusions: Although both dentifrices were found to successfully occlude dentinal tubules, the dentifrice containing SnF₂ and NaF provided the highest degree of occlusion in periodontally involved teeth.

Purpose: This study aimed at evaluating the effects of surface treatments with tetrabutylammonium dihydrogen trifluoride (TDTF) on the bond strengths of indirect resin composites with titanium-aluminum-vanadium (Ti-6Al-4V) and cobalt-chromium (Co-Cr) alloys.

Methods: Disk-shaped Ti-6Al-4V and Co-Cr alloy specimens were air-abraded with alumina, treated with an etchant (MEP) containing TDTF for 10 s (MEP10) or 30 s (MEP30), and rinsed with water. Subsequently, a primer containing 6-methacryloyloxyhexyl phosphonoacetate was applied to the surfaces, and the specimens were veneered with a light-curing indirect resin composite. Specimens without MEP were prepared as controls (no-MEP). Shear bond strengths were determined before or after 100,000 thermocycles, and the data were analyzed using the Steel-Dwass test (α = 0.05, n = 10).

Results: No significant difference was found in the bond strengths between the Ti-6Al-4V and Co-Cr alloys. In each metal alloy, the MEP10 and MEP30 specimens exhibited higher bond strengths than the no-MEP controls after 100,000 thermocycles. Scanning electron microscopy observations revealed that submicron-pits and crevices were formed on both the metal alloys upon applying the MEP etchant.

Conclusion: Surface treatments with TDTF following air abrasion are useful for improving bonding durability while veneering resin composites on Ti-6Al-4V or Co-Cr alloy frameworks.

Purpose: Medication-related osteonecrosis of the jaw (MRONJ) is characterized by necrosis of the jawbone with intraoral bacterial infection and has a significant negative impact on oral health-related quality of life. Risk factors for the onset are unknown, and definitive therapeutic approaches have not yet been defined. A case-control study at a single institution in Mishima City was conducted. The purpose of this study was to examine in detail the factors that contribute to the development of MRONJ.

Methods: Medical records of MRONJ patients who visited Mishima Dental Center, Nihon University School of Dentistry, during the period 2015-2021 were extracted. Counter-matched sampling design was used to select participants matched for sex, age, and smoking for this nested case-control study. The incidence factors were statistically examined by logistic regression analysis.

Results: Twelve MRONJ patients were used as cases and 32 controls were matched. After adjustment for potential confounders, injectable bisphosphonates (aOR = 24.5; 95% CI = 1.05, 575.0; P < 0.05) were significantly associated with the development of MRONJ.

Conclusion: High-dose bisphosphonates may be a risk factor for the development of MRONJ. Patients who use these products require careful prophylactic dental treatment against inflammatory diseases, and dentists and physicians should maintain close communication.