Journal of Applied Oral Science最新文献

Objective: This study aimed to evaluate whether the use of desensitizing dentifrices containing obliterating agents can affect bond strength of eroded/abraded dentin.

Methodology: A total of 100 dentin samples were obtained from human molars. The teeth were cut into 3 mm-thickness discs and allocated in five groups (n=20), according to the toothpaste used: WoF - abrasion with fluoride-free toothpaste (Cocoricó); Arg - toothpaste containing arginine (Colgate Sensitive Pro-Relief); Nov - calcium sodium phosphosilicate toothpaste (Sensodyne Repair and Protect); SnF - fluoride-containing toothpaste (AmF/SnCl2/SnF2 - Elmex Erosion); and Control (no erosive/abrasive process). The erosive/abrasive cycle consisted of immersion in citric acid (1%, pH 2.6, 5 min, 4×/day) and abrasion (2×/day, 120-20 sec abrasion, 100 sec immersion) with each toothpaste. During intervals, samples were immersed in artificial saliva. This cycle was performed for five days. Two resin cylinders (2 mm in diameter) were constructed on each sample for the shear bond strength test using a universal adhesive system. The self-etch and etch-and-rinse (Scotchbond Universal) strategies were employed, each in half of the total sample (n=10). Bond strength (MPa) was measured in a shear test and failure modes were assessed with a stereomicroscope. Statistical analysis was performed using the two-way analysis of variance (ANOVA) and Tukey tests (p<0.05).

Results: A statistically significant difference was found between the adhesive strategies tested (p<0.001), with the self-etching form showing higher values than the etch-and-rinse. Moreover, no significant differences were observed between the tested toothpastes (p=0.750) and interactions (p=0.438).

Conclusion: The use of toothpaste containing obliterating agents does not affect bond strength to dentin subjected to erosive/abrasive conditions when a universal adhesive is used. However, the self-etch strategy might be preferred for eroded/abraded dentin.

Objective: Recently, the DC/TMD has become an essential tool for the diagnosis of temporomandibular disorders (TMD). However, as they fail to include functional activities, new assessment proposals have emerged, such as the isometric contraction test (IC test) of the masticatory muscles, which uses muscle contractions to identify muscular TMD. This study aimed to determine the test-retest reliability of the IC test.

Methods: A total of 64 participants (40 women and 24 men) completed the IC test administered by two different physical therapists on two non-consecutive days. Cohen's kappa (k), PABAK, and percent agreement (PA) between days were estimated.

Results: The IC test showed good to excellent test-retest reliability values (k>0.77; PABAK>0.90), both globally and individually for the muscles evaluated, and PA>90%, therefore above the thresholds for clinical applicability. However, the global assessment of myofascial pain and the evaluation of the medial pterygoid muscle showed slightly lower reliability values.

Conclusion: The IC test is reliable for the assessment of subjects with muscular TMD, both in terms of the global assessment and the evaluation of each muscle, which supports its clinical applicability. Care should be taken when assessing myofascial pain globally and when evaluating the medial pterygoid in all types of pain.

Objective: Radiotherapy after head and neck cancer is associated with the risk of osteonecrosis development. This study aims to investigate the effectiveness of systemic propolis application to prevent the disease as it has no definite treatment protocol despite the proposed treatment methods and significantly decreases individuals' quality of life.

Methodology: In total, 29 male Wistar-Albino rats were divided into control, 35 Gy irradiation (Group 1), 35 Gy irradiation+100 mg/kg/ml propolis administration (Group 2), and 35 Gy irradiation+200 mg/kg/ml propolis administration groups (Group 3). Propolis was first applied on the day after radiotherapy, except for the control group. Right first and second molars were extracted from all rats three weeks following radiotherapy. Samples were collected seven weeks after radiotherapy. Osteoblast and osteoclast counts were calculated by histomorphometric analysis. Immunohistochemical analysis determined bone morphogenic protein-2 (BMP-2) and transforming growth factor beta-3 (TGFβ-3).

Results: Group comparison found non-significant differences regarding osteoblast (p=0.130) and osteoclast (p=0.063) counts. However, Group 1 showed the lowest mean osteoblast (OBL: 82.63 [±13.10]) and highest mean osteoclast counts (OCL: 12.63 [±5.55]). OBL/OCL ratio showed significant differences between groups (p=0.011). Despite the significant difference between the Control and Groups 1 (p=0.006) and 2 (p=0.029), Group 3 showed a non-significant difference (p=0.091). For BMP-2 and TGFB3, the control group showed significant differences with the other two groups (p<0.001), except for Group 3.

Conclusion: Anatolian propolis showed beneficial effects in a radiotherapy-mediated osteonecrosis model, highlighting its potential as a promising intervention.

Objective: The use of a fiber glass post (FGP) type and choice of FGP diameter to restore endodontically treated incisors without ferrule is controversial. This study evaluated survival rate and failure mode of severely compromised central incisors without ferrule rehabilitated using resin-based composite (RBC) with or without FGP with different diameters.

Methodology: A total of 60 decoronated bovine incisors without a ferrule were endodontically treated and prepared for 1.4, 1.6, and 1.8 mm diameter FGPs (Whitepost System DC 0.5, Fit 0.4, and DCE 0.5; FGM). Half of the teeth received FGPs cemented using dual-cure resin cement (Allcem Core; FGM), the other half were filled using only bulk-fill RBC (OPUS Bulk Fill; FGM). The crowns were directly restored with RBC. The roots were embedded in polystyrene resin and the periodontal ligament was simulated with polyether impression material. Fatigue testing was conducted under 5 Hz cyclic loading at 30 degrees to the incisal edge, beginning at 50 N (5,000 cycles) as a warmup. After, the load was increased 100 N every 15,000 cycles until fracture occurred. All specimens were subjected to transillumination, micro-CT analysis, and digital radiography before and after fatigue testing. Fracture mode was classified according to severity and repair potential. Data were analyzed with Kaplan-Meier survival test and post hoc log-rank test (α=0.05) for pairwise comparisons.

Results: Using FGP significantly increased the number of cycles to failure, irrespective of FGP diameters (p=0.001). The FGP diameters had no statistically significant effect on cycles to failure or failure mode.

Conclusion: Using FGP without ferrule improved survival rate of structurally severely compromised central incisors compared with rehabilitation without FGP. The diameter of the FGPs had no effect on the survival rate and failure mode.

Objective: The search for treatments that accelerate the healing of lesions is of constant interest. Matricaria recutita (chamomile) is a plant with antimicrobial, anti-inflammatory, and healing properties, and antimicrobial Photodynamic Therapy (aPDT) eradicates microorganisms, which favors tissue repair. This study aimed to evaluate the effect of the topical use of chamomile with or without aPDT on tissue repair in rats' tongues.

Methodology: A total of 75 male Wistar rats underwent standardized ulceration on the dorsum of the tongue using a punch of 5 mm diameter and were randomly allocated into the following groups: control (G1), chamomile fluid extract (G2), chamomile infusion (G3), aPDT (G4), and chamomile infusion + aPDT (G5). On the 3rd, 7th, and 14th days postoperatively, euthanasia was performed, and the ulcers were measured using calipers. The presence of edema, inflammatory infiltrate, cellularity, re-epithelialization, and characterization of total collagen were evaluated using sections stained with Hematoxylin and Eosin and Red Sirius. Histomorphometry analyses of the percentage of total collagen, the distance from the basal layer to the epithelial surface, and the thickness of the stratum corneum were performed. Descriptive (absolute/relative frequencies and modes) and exploratory analyses were performed. The associations between the groups and the presence of ulcers were analyzed with Fisher's exact test. All analyses were performed using the R program and statistical significance was set at p=0.05.

Results: The G2 positively modulated the exudative and proliferative phases of repair, both clinically (p<0.0001) and histologically, whether in descriptive or inferential analyses (p<0.05). The G3 showed a significant difference in clinical parameters compared with G1 (p<0.0001). The G4 and G5 did not positively modulate tissue repair.

Conclusion: The chamomile fluid extract showed better outcomes for tissue repair in the rat tongue.

Objective: Despite the availability of in-office bleaching gels with a 6% concentration of hydrogen peroxide (HP), these gels have not been evaluated in younger patients. They are commercially available with a tip, associated or not with a brush, where the tip with a brush spreads the gel over the entire surface to have a smaller thickness (thin layer) since the manufacturers indicate the application of a thin layer of gel. This randomized, split-mouth, double-blind clinical trial evaluated the efficacy of in-office bleaching with 6% HP in adolescents using different application tips, as well tooth sensitivity (TS) and aesthetic self-perception.

Methodology: Sixty participants were randomized for 6% HP self-mixing bleaching gel tip design: without brush and with brush. In-office bleaching was performed in 3 sessions of 50 minutes. Color change was evaluated using a digital spectrophotometer (ΔE ab , ΔE 00 , and ΔWI D ) and color guide (ΔSGU), the absolute risk and intensity of TS with a visual analogue scale and aesthetic self-perception with the oral aesthetic scale (a=0.05).

Results: The groups achieved similar bleaching regardless of the application tip (p>0.05). However, only for ΔWI D , a significant mean difference (MD) was observed in the third week (MD 2.3; 95% CI 1.2 to 3.3; p < 0.001) and at one month (MD 1.6; 95% CI 0.6 to 2.6; p < 0.03) favoring the tip without brush. Regarding TS, 45% in the tip-without-brush group and 33% in the tip-with-brush group reported TS (odds ratio 0.61; 95% CI 0.29 to 1.28; p<0.02), with low TS intensity (MD 0.05; 95% CI -0.06 to 0.17; p>0.36). All patients reported improved aesthetic self-perception after bleaching (MD -1.3; 95% -1.8 to -0.9; p<0.001).

Conclusions: Regardless of the tip used bleaching with 6% HP achieved a bleaching efficacy and improved the aesthetic self-perception. However, a lower risk of TS for application using the tip with brush was observed.

[This corrects the article doi: 10.1590/1678-7757-2022-0076].

Background: Hall technique (HT) has been indicated for teeth with dentinal caries lesion; however, extensive cavities, with more than two surfaces still seem challenging for restorative treatment in pediatric dentistry, resulting in a higher failure rate and an increased need for retreatment.

Objectives: To compare the survival rate of the Hall technique preformed metal crown (HT) with resin composite restoration (RC) for multi-surface cavitated caries lesions in primary molars.

Methodology: In this multicenter two-arm randomized clinical trial, children between 4 and 9 years of age with at least one primary molar with cavitated caries lesion involving more than two surfaces, including one buccal or palatal/lingual surface, were selected from 17 Brazilian cities. A total of 364 teeth were allocated into two groups: (1) teeth treated with selective caries removal and RC and (2) treated with the HT. The survival rate was assessed at 6 and 12 months after the interventions. Survival analysis was performed with the Kaplan‒Meier method. Cox regression was used to determine the influence of explanatory variables on the survival rate (α=5%).

Results: After 12 months, 292 teeth were re-evaluated. A total of 358 teeth were re-evaluated at least once during the study and included in the survival analysis. The HT (87.8%) resulted in a higher survival rate than RC restoration (75.7%) (p=0.004).

Conclusion: HT has a higher survival rate than RC as a treatment for multi-surface cavitated caries lesions in primary teeth. ClinicalTrials.gov: NCT02782390.

The effectiveness of at-home dental bleaching treatments depends on the time that bleaching products are in contact with the teeth surface and, consequently, on the adequate use of associated custom acetate trays.

Objective: This randomized single-blinded trial aimed to analyze if the daily usage time of these products influences the patient's compliance behavior when submitted to monitored at-home dental bleaching. Secondary outcomes were color change and tooth sensitivity.

Methodology: Sixty-six volunteers were randomly distributed into three groups (n=22): patients were instructed to use the trays for 2 (G2), 4 (G4), and 8 (G8) hours daily. The daily dental bleaching compliance behavior was measured using a microsensor inserted into the trays. Subjective and objective color evaluation assessments were adopted at baseline (T0), one (T1), two (T2), and three weeks (T3) after the beginning of the bleaching treatment, as well as two weeks after the treatment (T4). Tooth sensitivity was analyzed using the VAS scale, ranging from T1 to T4.

Results: G2 showed a greater degree of cooperation than G8 and cooperation was inversely proportional to the recommended usage time. Significantly higher color change was observed in the upper arch for G8 when compared to G2 in subjective analysis, from T1 to T4. There were no statistical differences between the groups in objective analysis.

Conclusion: Shorter recommended usage time of the bleaching product may improve the patient's compliance with at-home dental bleaching treatments. However, increased daily usage time may promote better subjective color change. Bleaching sensitivity was more significant in the first week for a longer time of use.

Objective: To evaluate the influence of RORγT inhibition by digoxin on inflammatory changes related to interleukin-17 (IL-17) in the pulp of rats treated with zoledronate (ZOL).

Methodology: Forty male Wistar rats were divided into a negative control group (NCG) treated with saline solution, a positive control group (PCG) treated with ZOL (0.20 mg/kg), and three groups treated with ZOL and co-treated with digoxin 1, 2, or 4 mg/kg (DG1, 2, and 4). After four intravenous administrations of ZOL or saline solution in a 70-day protocol, the right molars were evaluated by histomorphometry (number of blood vessels, blood vessels/µm2, cells/µm2, total blood vessel area, and average blood vessel area) and immunohistochemistry (IL-17, TNF-α, IL-6, and TGF-β). The Kruskal-Wallis/Dunn test was used for statistical analysis.

Results: PCG showed an increase in total blood vessel area (p=0.008) and average blood vessel area (p=0.014), and digoxin treatment reversed these changes. DG4 showed a reduction in blood vessels/µm2 (p<0.001). In PCG odontoblasts, there was an increase in IL-17 (p=0.002) and TNF-α (p=0.002) immunostaining, and in DG4, these changes were reversed. Odontoblasts in the digoxin-treated groups also showed an increase in IL-6 immunostaining (p<0.001) and a reduction in TGF-β immunostaining (p=0.002), and all ZOL-treated groups showed an increase in IL-17 (p=0.011) and TNF-α (p=0.017) in non-odontoblasts cells.

Conclusion: ZOL induces TNF-α- and IL-17-dependent vasodilation and ectasia, and the classical Th17 response activation pathway does not seem to participate in this process.