American journal of dentistry最新文献

Purpose: To evaluate the effect of different decontamination protocols on the bonding strength of MDP-containing resin cement to saliva-contaminated zirconia ceramic.

Methods: 144 zirconia samples (12 mmx12 mmx1.2 mm) were prepared from 4Y-TZP and 6Y-TZP blocks, sandblasted with 50 μm Al₂O₃, and contaminated with artificial saliva. Samples were divided into six groups (n=24) based on decontamination method: sintered (CON), Rocatec-treated (ROC), Al₂O₃ abraded (AL), water-cleaned (HO), Ivoclean-treated (IVO), and 37% H₃PO₄-cleaned (PH). Pre-prepared resin cylinders (2.0 mm diameter, 3.0 mm height) were bonded to zirconia using MDP-containing resin cement (Panavia SA) and light-cured. All bonded samples underwent thermocycling (5°C-55°C, 10,000 cycles for 1 week, 50,000 cycles for 6 months, and 100,000 cycles for 12 months) to simulate intraoral aging. Shear bond strength was assessed at 1 week, 6 months, and 12 months using a universal testing machine. Surface roughness parameters (Rq, Ra) were measured with a digital profilometer, and adhesive failures were analyzed via scanning electron microscopy (SEM). Data were evaluated using one-way ANOVA and Tukey's post hoc test (α= 0.05). Weibull analysis was performed to assess the reliability and probability of bond strength failure. Additionally, Kaplan-Meier survival analysis was conducted to evaluate the long-term durability of resin-zirconia bonds over time.

Results: For 4Y-TZP, Ivoclean (1768±32 MPa) and Al₂O₃ abrasion (1541±36 MPa) achieved the highest shear bond strengths at 1 week. In contrast, 6Y-TZP exhibited lower bond strengths, with sintered and Rocatec-treated groups performing moderately. Surface roughness analysis showed that sintered and Ivoclean-treated 4Y-TZP had lower roughness (Rq ~14.8, Ra ~0.5), while 6Y-TZP had higher values, particularly after H₃PO₄ treatment (Rq 61.6, Ra 119.7).

Clinical significance: Selecting appropriate decontamination methods such as Ivoclean application or airborne-particle abrasion with Al₂O₃-based on the zirconia type is essential to achieve durable resin bonding and ensure the long-term success of high-translucency zirconia restorations.

Purpose: To assess the efficacy and safety of Glister multi-action toothpaste Herbals (GHT) on gingivitis in diabetic subjects.

Methods: A total of 72 diabetic subjects were enrolled and 61 subjects completed the open label single arm clinical study for a period of 30 days. Subjects were evaluated on Day 10 (visit 3), Day 20 (visit 4), and Day 30 (visit 5) for reduction in gingivitis, plaque, gingival bleeding, pocket depth, S. mutans count, hypersensitivity, teeth whiteness, extrinsic stains, malodor, product tolerance, product sensory experience and product perception.

Results: Modified Gingival Index mean (SD) score was 1.91 (0.82) at screening, reduced to 1.5 (0.9) at Day 10, 1.4 (0.8) at Day 20 and 1.2 (0.6) at Day 30, respectively. The P-value was highly significant (P< 0.0001) on Days 10, 20 and 30 when compared to screening as well as from Day 10 to Day 20, and Day 20 to Day 30.The Modified Plaque Index mean (SD) score was 1.6 (0.7) on screening day which reduced to 1.3 (0.7) on Day 10, 1.1 (0.7) on Day 20 and 1.0 (0.6) on Day 30, respectively from screening. Significant reduction (P< 0.0001) in plaque was observed in as early as 10 days of regular usage. Similarly, gingival bleeding reduced significantly (P< 0.0001) from screening day value 86.5 (16.1) to Day 10 value of 66.9 (19.8), and on Day 20 to 47.5 (15.5) and Day 30 to 33.0 (12.8), respectively. The S. mutans mean (SD) count from the screening day count of 43,259.7 (10,455.63) CFU/ml was reduced after the use of GHT on Day 10 to 38,662.3 (10,501.81), on Day 20 to 33,019.7 (9,803.31) and on Day 30 to 28,344.3 (9,404.42) CFU/ml respectively. At the screening visit, the malodor mean (SD) score was 2.2 (1.2), which was reduced to 1.8 (1.1) on visit 3, to 1.4 (1.0) on visit 4 and to 1.0 (0.8) on visit 5 respectively with statistical significance of P< 0.0001 on Day 10 compared to baseline, Day 20 compared to baseline and Day 10 and also on Day 30 as compared to other two intervals.

Clinical significance: In the current study, Glister Multi-action Toothpaste Herbals demonstrated a clinically significant improvement in diabetic subjects as measured by gingival index, bleeding index, plaque index, malodor and S. mutans count. The toothpaste was well accepted by the subjects without any adverse effects. Thus, this toothpaste may be beneficial in improving gum health among those with diabetes.

Purpose: To explore the potential association between acute periapical abscesses (PAs) and medication-related osteonecrosis of the jaw (MRONJ). The study assessed the risk for MRONJ in patients seeking emergency dental treatment for acute PAs in a large medical facility in the United States.

Methods: Data aggregated from 1,799,122 patients visiting a large medical center were recorded. Data from the corresponding diagnosis codes for MRONJ and acute PAs was retrieved by searching the appropriate query in the database. The odd ratio of acute PAs and their association with MRONJ were calculated and analyzed statistically.

Results: Patients with PAs showed significantly more MRONJ cases. The odds ratio (OR) of patients receiving all types of bisphosphonates (BPs) was 6.21 and was statistically significant (P< 0.0001). The OR of patients receiving alendronate was 5.33 and was statistically significant (P= 0.0001). Following adjustment for diabetes co-morbidity, the OR for MRONJ patients with acute PAs was 5.33. The difference in prevalence compared to the total hospital patient population was statistically significant (P= 0.0001). Following adjustment for smoking co-morbidity, the OR for MRONJ in patients with acute PAs was 4.44. The difference in prevalence as compared to the total hospital patient population was statistically significant (P= 0.001).

Clinical significance: Oral healthcare providers should be aware of the possible association between MRONJ and the higher occurrence of acute periapical abscesses. Enhanced oral hygiene and frequent dental visits are recommended to diagnose and treat dental pathoses promptly in MRONJ patients.

Purpose: To evaluate the laboratory accuracy of three intraoral scanners (IOSs) across three types of tooth preparations, using a laboratory scanner as the reference.

Methods: Models of three types of tooth preparations (inlay, onlay, and three-unit fixed partial denture) were designed with CAD software and fabricated using a 3D printer. Reference data were obtained by scanning these models with a desktop laser scanner (Identica Hybrid, Medit Co). Each model was scanned five times using three IOSs: TRIOS4 (3Shape), I500 (Medit Co), and COMFORT+ (DDS), resulting in 45 scans across nine groups. Scan files were exported in STL format and analyzed with Geomagic 3D inspection software. Accuracy was assessed using best-fit alignment and 3D comparison functions.

Results: Trueness did not significantly differ among the IOSs within each tooth preparation group (P> 0.05). However, all three IOSs showed significantly lower trueness for the three-unit fixed partial denture compared to the inlay and onlay groups (P< 0.05). Precision significantly varied among the IOSs within the tooth preparation groups (P< 0.05). Specifically, the I500 demonstrated higher precision for inlays, while TRIOS4 and I500 exhibited better precision for onlays and three-unit fixed partial dentures.

Clinical significance: All three tested intraoral scanners (TRIOS, I500, and COMFORT+) demonstrated clinically acceptable accuracy for prostheses fabrication, confirming their suitability for applications ranging from inlays to crowns and bridges.

Purpose: To evaluate the efficacy of hydrogen peroxide, sodium hypochlorite, and glutaraldehyde in disinfecting dental impression materials; alginate, polyether, condensation silicone and polyvinyl siloxane. The objectives include comparing the microbial reduction (Log R values) and assessing the interaction between microorganisms and disinfectants on these materials.

Methods: Common dental pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae, and Streptococcus mutans) were used to contaminate the impression materials. Each contaminated sample was disinfected using hydrogen peroxide, sodium hypochlorite, or glutaraldehyde. Microbial reduction was measured as Log R values. Statistical analyses included Kruskal-Wallis tests and Bonferroni post hoc analyses.

Results: Significant differences in Log R values were observed among the impression materials and disinfectants. Alginate exhibited lower Log R values (4.63 ± 1.56) compared to polyether and polyvinyl siloxane. Sodium hypochlorite showed superior microbial reduction (5.38 ± 0.84) compared to hydrogen peroxide (4.84 ± 1.44). Pseudomonas aeruginosa and Streptococcus mutans had higher Log R values, indicating greater susceptibility to the disinfectants. Glutaraldehyde demonstrated effective microbial reduction (5.51 ± 0.69), with Log R values comparable to sodium hypochlorite (5.38 ± 0.84), making it a potent disinfectant for dental impression materials.

Clinical significance: The study demonstrates that sodium hypochlorite and glutaraldehyde are highly effective in reducing microbial load on dental impression materials. While sodium hypochlorite and glutaraldehyde are recommended for their higher efficacy, hydrogen peroxide offers a safer, less toxic alternative, making it a viable option in specific clinical situations.

Purpose: To evaluate the laboratory effect of the cut-out-rescan procedure and the rubber dam color on the trueness of two intraoral scanners (IOS).

Methods: An onlay preparation was performed on a typodont maxillary left 1st molar. The left hemi-arch of the maxilla was scanned using two IOS (Trios 3, 3Shape; n=20). These digital scans were defined as references and exported. The prepared tooth and 1 mm proximal surfaces were cut-out using the IOS' software tools. Following the rubber dam (blue-color) isolation, the cut-out area was rescanned and recorded. Reference and rescan data in .STL were uploaded to the software programs and superimposed. The deviations were obtained selectively for the teeth. Also, additional hemi-arc rescans with different rubber dam sheet colors (blue, purple, and black) were obtained and superimposed with reference scan without cut-out procedure. Trueness was evaluated using root mean square (RMS) error by Geomagic Control X and mean distance (Md) by Oracheck. Data were analyzed using ANOVA, Shapiro-Wilk, and Independent Samples (P< 0.05).

Results: The Md values by the Trios 3 were significantly higher than Omnicam for the 1st premolar and 1st molar (P< 0.05). Omnicam's RMS and Md values for the 2nd molar were significantly higher than 1st premolar and 1st molar (P< 0.001). Trios's RMS values were significantly higher for the 2nd molar than the 1st molar (P< 0.001). A lower deviation in Md values was obtained for black rubber dam color compared to the blue and purple in Omnicam and the purple in Trios (P< 0.005).

Clinical significance: The cut-out-rescan procedure may influence the scanning trueness depending on the IOS and location of the cut-out area. The use of the cut-out-rescan procedure will be optimized by considering the technology and software of the IOS. The black rubber dam was considered the optimal choice when using the rescan procedure.

Purpose: To evaluate the effectiveness of the deep convolutional neural network model for the detection of dental caries on panoramic radiographs.

Methods: A total of 2660 images of healthy and decayed labeled teeth were obtained from 101 panoramic radiographs. A total of 5,000 data sets were created by obtaining 2,340 synthetic data from real data. The total dataset is randomly divided as 80% training data and 20% test data. A deep learning model was created using the ResNet50 deep convolutional neural network architecture and model performance was measured after the model training. All data was evaluated and diagnostic accuracy, sensitivity, specificity, PPV (positive predictive value), NPV (negative predictive value), ROC (receiver operator characteristics) curve and AUC (area under the curve) were calculated for the detection and diagnostic performance of the deep learning method with ResNet50.

Results: The deep learning model classified 500 healthy and 500 decayed tooth data at a rate of 82%. The deep learning model's PPV value was 75.8%, NPV value was 92%, sensitivity 94% and specificity 70%. The AUC value was found to be 82%.

Clinical significance: The deep learning model used for the detection of caries in panoramic radiography is promising for use as an auxiliary tool for dentists in clinical practice.

Purpose: To initially evaluate the efficacy of a novel non-peroxide-based whitening strip (Dithionite White) on beverage colorants and doxycycline-stained teeth.

Methods: In the evaluation of the beverage-stained teeth, two small areas (incisal-enamel and cervical-dentin) were exposed on bovine teeth for staining; the samples were divided into six treatment groups (n= 90) and three treatment protocols. The teeth were immersed for 14 days into six treatment groups: red wine, coffee, cola, tea, soy sauce, and an equal-part cocktail of previously listed colorants. The control group (n= 3) remained immersed in de-ionized water. The teeth were treated twice daily with Crest Whitestrips for 30 minutes and a whitening agent Dithionite White (DW) for 30 and 60 minutes on days 1, 3, 5, 7, and 14; the tetracycline-stained teeth were divided (80 teeth in the study) into eight groups (n= 10). These teeth were bleached daily. The bleaching effectiveness of the blue LED and Red infrared lights was evaluated as well as the use of mouthwash to enhance the bleaching environment. For all groups, the color change was assessed with a spectrophotometer. For the beverage-stained teeth, measurements were taken at baseline pretreatment, post-stain, 1 day, 3 days, 5 days, 7 days, and 14 days posttreatment. For the tetracycline-stained teeth, weekly measurements were obtained for 11 weeks. In each study L*, a*, b* at each period of bleaching was compared to the baseline. The color difference (ΔE) was calculated. The means ΔE were compared with multiple ANOVA tests and a MANOVA test.

Results: In the beverage-stained and doxycycline-stained teeth, both bleaching systems showed color improvement.

Clinical significance: The results of this study support the effective use of Dithionite White (non-peroxide based) as an effective bleaching agent. Additional treatment beyond 30 minutes of DW did not significantly increase bleaching results. The adjunctive use of blue and infrared LED lights and alkalizing mouthwashes may enhance bleaching effectiveness.

Purpose: To evaluate the changes in color, translucency, roughness, and depth loss of various composites with different formulations (Filtek One Bulk Fill, Admira Fusion X-tra Bulk-fill, and XRV Herculite) after toothbrushing using dentifrices containing charcoal and charcoal-free.

Methods: 32 resin composite discs (8.0 x 1.5 mm) were prepared for each Filtek One Bulk Fill, Admira Fusion X-tra Bulk-fill, and XRV Herculite. Discs were evaluated with a spectrophotometer for color and roughness measurements before and after treatments. Sample treatment included toothbrushing on a V-8 toothbrushing machine for 10,000x to simulate daily oral care with four different dentifrices (Colgate Total SF, Crest Pro-Health Complete Protection Intensive Cleaning+Whitening, Colgate Total Whitening Charcoal, and Crest Charcoal 3D White). After toothbrushing, color (ΔE₀₀), roughness (Ra and Rz), depth loss (DL), and translucency (TP₀₀, and ΔTP₀₀) were remeasured and deduced from initial measurement for the standard difference in each respective parameter. Data were calculated and statistically analyzed independently using a two-way repeated measures ANOVA and Holm-Sidak post-hoc test with P< 0.05 significance.

Results: Admira and Filtek, when brushed with Colgate Total SF resulted in less roughness and DL when compared to both charcoal dentifrices. Admira was found slightly rougher than Herculite and Filtek with Crest Pro-Health and similar to both charcoal groups. However, Admira with Crest Pro-Health was similar to Herculite and Filtek but significantly different from both charcoal groups. All dentifrices had a significant staining effect on all composites relative to the baseline color. Admira and Filtek composites were above the clinical acceptance threshold (AT) of 1.8 for ΔE₀₀, with Herculite only surpassing the limit with Crest Charcoal. Lastly, Herculite with all dentifrices was below the clinical perceptibility threshold (PT) for translucency difference. Both Admira and Filtek were above the ΔTP₀₀ PT but less than the AT for all dentifrices except Colgate Charcoal.

Clinical significance: Charcoal dentifrices changed the color of Admira samples. Colgate charcoal resulted in a significantly different color change versus using Colgate Total and Crest Pro-Health. All three resins resulted in statistically significant color change when using all non-charcoal-containing dentifrices.

Summary: The dental profession is evolving rapidly, integrating new technologies and methods to improve patient care. As demand for dental bleaching grows, it is essential to provide treatments that prioritize both safety and efficacy. This special issue of the American Journal of Dentistry presents the latest research and ethical considerations in dental bleaching, examining the intersection of technological innovation, natural whitening options, and ethical standards. The articles in this issue underscore the importance of safety and effectiveness in dental bleaching. Recent advancements, from artificial intelligence to optimize protocols to new methods like violet LED bleaching and non-peroxide based dental bleaching have transformed treatment options. However, each innovation requires rigorous clinical testing and research to ensure it meets safety and efficacy standards across diverse patient populations.