scholarly journals Effect of photo-thermal acceleration on in-office bleaching

Odontology ◽  
2021 ◽  
Author(s):  
Feng Qi ◽  
Masayuki Otsuki ◽  
Noriko Hiraishi ◽  
Takashi Hatayama ◽  
Chamari Lasindra Wijethunge ◽  
...  

AbstractThe purpose is to evaluate the effect of photo-thermal acceleration on in-office bleaching efficiency using a bleaching agent without photocatalysts in vitro. Artificially discolored bovine lower incisors were prepared, and the mixed in-office bleaching material contained hydrogen peroxide 23% was applied by following treatment for 10 min: high-(HI group) and low-intensity LED lights (LI group), oven at 38 °C (OV group), and room temperature at 23 °C (RT group). Color was measured before and after bleaching and color difference (∆E*) was calculated. The data were statistically analyzed using a two-way ANOVA and Tukey’s post hoc test. The temperature change (∆T) of applied bleaching agent in HI and LI groups was measured using a thermography and was analyzed using a T test. The bleaching procedures were repeated 6 times. Irradiation in the HI group resulted in the highest ΔE, followed by the LI group whose ΔE was significantly lower. Both irradiated modes exhibited higher ΔE compared to non-irradiated OV and RT groups which were not significantly different from each other. The average temperature rise of bleaching agents in HI and LI groups after 10 min irradiation was 15.00 °C and 11.80 °C, respectively. The effect of photo-thermal acceleration was proved for an in-office bleaching agent without photocatalysts in vitro.

Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.


2009 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Fernando Henrique Ruppel Osternack ◽  
Danilo Biazzetto de Menezes Caldas ◽  
Rodrigo Nunes Rached ◽  
Sérgio Vieira ◽  
Jeffrey A. Platt ◽  
...  

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.


Medicina ◽  
2019 ◽  
Vol 55 (11) ◽  
pp. 749 ◽  
Author(s):  
Satheesh B. Haralur ◽  
Noura Raqe S. Alqahtani ◽  
Fatimah Alhassan Mujayri

Background and aim: All-ceramic prosthesis is widely used in modern dental practice because of its improved physico-mechanical and optical properties. These restorations are exposed to coloring agents from various nutrition and beverages in the oral cavity. Long-term color stability is critical for the success of these restorative materials. The purpose of this in vitro study was to assess the effect of common beverages and mouthwash on the color stability of lithium disilicate (LD), monolithic zirconia (MZ) and bilayer zirconia (BZ) surfaces. Material and methods: Thirty disc-shaped specimens from each material were fabricated; each group was subdivided (n = 10) according to coffee, green tea and chlorhexidine immersion solutions. The baseline color of ceramic discs was recorded according to the CIE L*a*b* system with a portable spectrophotometer. The second measurement was recorded after 3000 thermocycling and immersion in coloring agents for 7 days. The mean color difference was calculated and data were compared with Kruskal-Wallis and Mann-Whitney post hoc tests (0.05). Results: ΔE values for LD with the immersion of coffee, tea, and Chlorhexidine gluconate (CHG) were 1.78, 2.241 and 1.58, respectively. Corresponding ΔE values for MZ were 5.60, 5.19, and 4.86; marginally higher than the clinically acceptable level of 3.5. Meanwhile, BZ showed better color stability compared to MZ with ΔE values of 4.22, 2.11 and 1.43. Conclusion: Among the ceramics evaluated, LD ceramic was found to be more color stable, while MZ ceramics displayed a higher susceptibility to discoloration. MZ and BZ ceramic colors were significantly altered with coffee immersion, while LD ceramics were more affected by green tea.


2019 ◽  
Vol 44 (6) ◽  
pp. 637-647 ◽  
Author(s):  
CAK Shimokawa ◽  
M Giannini ◽  
CB André ◽  
BO Sahadi ◽  
JJ Faraoni ◽  
...  

SUMMARY Objectives: This study evaluated the effect of toothbrushing with a dentifrice on gloss, roughness profile, surface roughness, and wear of conventional and bulk-fill resin-based composites. Methods and Materials: Gloss and surface roughness of resin-based composites (RBCs; Admira Fusion X-tra, Aura Bulk Fill, Filtek Bulk Fill Flowable, Filtek Bulk Fill Posterior Restorative, Filtek Supreme Ultra, Herculite Ultra, Mosaic Enamel, SDR flow+, Sonic Fill 2, Tetric EvoFlow Bulk Fill and Tetric EvoCeram Bulk Fill) were analyzed before and after brushing; the roughness profile and wear were also determined after toothbrushing. Representative three-dimensional images of the surface loss and images comparing the unbrushed and brushed surfaces were also compared. Analysis of variance and Tukey post hoc tests were applied (α=0.05) to the gloss, surface roughness, roughness profile, and surface loss data. Pearson's correlation test was used to determine the correlation between gloss and surface roughness, surface loss and percentage of gloss decrease after brushing, and surface loss and surface roughness after brushing. Results: For all RBCs tested after 20,000 brushing cycles, the gloss was reduced and the surface roughness increased (p&lt;0.05). However, the roughness profile and the amount of surface loss were dependent on the RBC brand. Admira Fusion X-tra, Aura, Tetric EvoCeram Bulk Fill, and Tetric EvoFlow Bulk Fill showed the deepest areas of wear (p&lt;0.05). A significant negative correlation was found between gloss and surface roughness, and a weak correlation was found between the decrease in gloss and the extent of surface loss, and any increase in surface roughness and the surface loss. Conclusions: Toothbrushing with a dentifrice reduced the gloss, increased the surface roughness, and caused loss at the surface of all the RBCs tested. Considering all the properties tested, Mosaic Enamel exhibited excellent gloss retention and a low roughness profile and wear, while Admira Fusion X-tra exhibited the greatest decrease in gloss, the highest roughness profile, and the most wear.


2018 ◽  
Vol 47 (5) ◽  
pp. 298-304
Author(s):  
Caroline de Farias CHARAMBA ◽  
Renally Bezerra Wanderley LIMA ◽  
Sônia Saeger MEIRELES ◽  
Rosângela Marques DUARTE ◽  
Ana Karina Maciel ANDRADE

Abstract Introduction In order to simplify the technique, reduce the time required for direct adhesive restorations, bulk-fill resin composites have been developed be applied in bulk placement up to 4 mm increments. Objective Evaluating the color change (ΔE) and the microtensile bond strength (μTBS) of bulk fill resin composites (BFRC) to dentin after the immersion in regular beverages and the application of bleaching systems. Method Forty-five human molar teeth were randomly distributed in three groups according to the filling material (n=15): Filtek Bulk Fill, Tetric N Ceram Bulk Fill and Filtek Z100. The restored teeth were immersed in coffee, wine and distilled water (n=5) for 72 hours. The color parameters were measured using a spectrophotometer, having as basis the CIE L*a*b*, before and after tooth staining and application of bleaching processes. Subsequently, the teeth were sectioned to obtain the specimens for the microtensile testing. The ΔE values were analyzed applying the Kruskal-Wallis and the Wilcoxon tests, and the μTBS values were analyzed applying the ANOVA and the Bonferroni tests (p<0.05). Result There were no significant differences in the ∆E values when comparing the BFRCs to the conventional resin composite (CRC) in most of the experimental groups. The ∆E values did not present significant differences before and after the application of bleaching processes for all the tested resin composites. The BFRCs presented higher μTBS values than the CRC after exposure to distilled water, wine and bleaching agent. Conclusion The studied BFRCs presented similar color stability to the CRC. The BFRCs presented higher bond strength to the dentin than the CTC in most of the evaluated conditions. The bleaching agent was not effective in whitening the stained restored teeth.


Author(s):  
Deebah Choudhary

Aim: To evaluate the influence of various obturating techniques on retreatment teeth. Place and Duration of Study: Department of Conservative Dentistry and Endodontics, Institute of Dental Sciences, Jammu and Kashmir, India between December 2019 and February 2020. Methodology: Sixty extracted mandibular premolars were randomly divided into three groups (n=20) based on the obturation technique adopted which endodontic treatment i.e., cold lateral compaction, thermoplasticized and GuttaFlow techniques. The samples were evaluated using micro-computed tomography for the volume before and after the retreatment to assess the remaining amount of filling material in the canals, and also the time taken for the removal of filling material during the retreatment. Data were analyzed using ANOVA followed by Post hoc test at P < 0.05. Results: The percentage of remaining filling material was between 17%-27%. The highest percentage of remaining filling material was seen in samples obturated with GuttaFlow (P < 0.05). The time required for retreatment was highly significant in thermoplasticized technique (P < 0.05). Conclusion: The type of obturating technique influenced the amount of filling material remained in the canal after retreatment and also the time taken during this removal.


2022 ◽  
Vol 10 (19) ◽  
pp. 29-33
Author(s):  
Sebastián M. Ulloa-Alvarez ◽  
María E. Guerrero-Coello ◽  
José E. Torracchi-Carrasco

Introduction: Endodontic retreatment seeks reentry to the root canal system to remove all filling material, identification and correction of pathological or iatrogenic defects. Objective: This study aimed to compare the dissolving capacity of eucalyptus oil, orange oil, and distilled water versus three types of endodontic cements. Materials and methods: Two hundred and four stainless steel molds were fabricated, where each cement sample was placed to the edge and left to set in the incubator, simulating normal oral conditions for 7 days. Subsequently, the solubility of each cement was analysed by immersing the samples in eucalyptus and orange oil for ten minutes in a static and ultrasonic environment. The solubility of the cement was evidenced by the difference between the weight before and after contact with the oils, data were statistically analysed with the ANOVA test and the post hoc Tukey bootstrap means test with 1,000 repetitions. Results: The control group and eucalyptus oil having no significant effect (p>0.05), the ultrasonic environment was found to be effective (p<0.05), whereas orange oil had better dissolution effects (p=0.004). Conclusions: The most susceptible cement was Sealapex, while the least soluble was MTA-Fillapex in all the solvents studied.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hanna Boes ◽  
Sören Brüstle ◽  
Gholamreza Danesh ◽  
Stefan Zimmer ◽  
Mozhgan Bizhang

AbstractPreventing biofilm-related risks such as gingivitis and white spot lesions during orthodontic treatments is very challenging. The cleaning efficiencies of AirFloss Ultra and I-Prox P sulcus brushes were evaluated using an orthodontic phantom model. After attaching brackets onto black-coated maxillary KaVo teeth, a plaque substitute was applied. The evaluated tooth surfaces were divided into two areas. Cleaning was performed with an AirFloss Ultra with two (A-2) or four (A-4) sprays or an I-Prox P for two (I-2) or four (I-4) seconds. Images before and after cleaning were digitally subtracted, and the percentage of fully cleaned surfaces was determined (Adobe Photoshop CS5, ImageJ). Statistical analysis was performed by ANOVA and post hoc tests with Bonferroni correction (SPSS 25, p < 0.05). The mean values of total cleaning efficacy were 26.87% for I-2, 43.73% for I-4, 34.93%, for A-2 and 56.78% for A-4. The efficacy was significantly higher for A-4 than for A-2, I-4, and I-2. There were significant differences between the four groups. Repeated cleaning led to an improved result. Within the study limitations, the AirFloss Ultra with four sprays proved to be more efficient than the sulcus brush I-Prox P for cleaning.


2018 ◽  
Vol 19 (2) ◽  
pp. 130-136 ◽  
Author(s):  
HP Vivek ◽  
Seema Geetha ◽  
Sabari Chandramohan ◽  
Md Imranulla ◽  
PB Srinidhi

ABSTRACT Aim The aim of the study was to evaluate the effect of mouthrinses containing olive oil, fluoride, and their combination on enamel erosion. Materials and methods An in vitro study of 45 enamel specimens, which were prepared from 45 extracted teeth, was employed. Each specimen was subjected to 10 alternative demineralization and remineralization cycles. Remineralizing cycle includes 5 minutes exposure with one of the mouthrinse, and demineralizing cycle includes 3 minute exposure to 1% citric acid. Mean surface roughness (Ra) was measured from surfometry before and after cycles. Statistical tests used were Student's unpaired t-test and one-way analysis of variance (ANOVA), followed by Tukey's post hoc test. Results Among the three mouthrinses, Listerine and Xerostom showed maximum protection against erosion on enamel. The 2% olive oil mouthrinse showed the least protection against erosion on enamel. Conclusion The study indicated that the Listerine and Xerostom mouthrinses are valuable preventive measures. Clinical significance Mouthrinses are effective for lessening erosive demineralization and in aggregating remineralization of tooth surfaces which are the important factors to prevent enamel erosion. How to cite this article Vivek HP, Prashant GM, Geetha S, Chandramohan S, Imranulla M, Srinidhi PB. Effect of Mouthrinses containing Olive Oil, Fluoride, and Their Combination on Enamel Erosion: An in vitro Study. J Contemp Dent Pract 2018;19(2):130-136.


Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1288
Author(s):  
Syed Rashid Habib ◽  
Abdulaziz Saud Al Rashoud ◽  
Turki Ali Safhi ◽  
Abdulrahman Hamad Almajed ◽  
Hamad Ali Alnafisah ◽  
...  

Background: To identify and compare the shade variations of various commonly used esthetic dental ceramics by calculating their total-color-difference (ΔE) and translucency parameter (TP) using a spectrophotometer. Methods: In total, 165 disc specimens from three shades (A1, B1, and C1) of five ceramic materials (N = 55/shade; n = 11/ceramic material group) were prepared (Metal-ceramic (MC), IPS e.max press (Emax-P), IPS e.max layer (Emax-L), Layered Zirconia (Zr-L) and Monolithic zirconia (Zr-M)). With a spectrophotometer, the L*a*b* values were obtained. Total color differences (ΔE = [(ΔL*)2 + (Δa*)2 + (Δb*)2]1/2) and translucency parameter (TP = [(L*B − L*W)2 + (a*B − a*W)2 + (b*B – b*W)2]1/2) were calculated. The statistical tests included ANOVA and Post hoc Tukey’s analysis (p < 0.05). Results: Significant differences (p = 0.000) were found between the groups for ΔE. Highest ΔE (A1) were found for Zr-L (80.18 ± 20) and lowest for Zr-M (62.97 ± 1.28). For B1, highest ΔE values were noted for MC (76.85 + 0.78) and lowest for the Emax-L (62.13 ± 1.49). For C1, highest ΔE values were found for the MC group (73.96 ± 0 67) and lowest for Emax-P (55.09 ± 1.76). Translucency variations between tested ceramics were revealed (p < 0.05). Highest TP values (A1) were found for Emax-L (2.99 ± 1.64) and lowest for Zr-L (0.35 ± 0.16). For B1, highest TP values were noted for Emax-P (3.50 ± 1.74) and lowest for MC (0.57 ± 0.40). For C1, highest TP values were found for Emax-P (4.46 ± 2.42) and lowest for MC (0.58 ± 0 48). Conclusions: Significant differences in ΔE and TP were found for tested ceramic groups. The color differences of the tested materials varied according to clinical acceptability, even with the selection of same color/shade. The color/shades of the various dental ceramics do not match with the vita shade guide tabs, to which they are compared most often. Shade differences are present between different lots of ceramic materials from the same or different brands.


Sign in / Sign up

Export Citation Format

Share Document