scholarly journals Cuspal Deflection and Temperature Rise of MOD Cavities Restored through the Bulk-Fill and Incremental Layering Techniques Using Flowable and Packable Bulk-Fill Composites

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5664
Author(s):  
Roberto De Santis ◽  
Vincenzo Lodato ◽  
Vito Gallicchio ◽  
Davide Prisco ◽  
Francesco Riccitiello ◽  
...  

Background: The aim of this study was to investigate cuspal deflection caused by material shrinkage and temperature rise occurring in the pulp chamber during photopolymerization. The aim of this study was also to investigate the effect of flowable and packable bulk-fill composites on cuspal deflection occurring in mesio-occlusal–distal (MOD) cavities restored through the bulk-fill or through the incremental layering technique. Additionally, mechanical and thermal properties of bulk-fill composites were considered. Methods: Two bulk-fill composites (high-viscosity and low-viscosity), largely differing in material composition, were used. These composites were characterized through linear shrinkage and compressive test. Cuspal deformation during restoration of mesio-occlusal–distal cavities of human premolars was evaluated using both the bulk-fill and the incremental layering techniques. Temperature rise was measured through thermocouples placed 1 mm below the cavity floor. Results: Shrinkage of the flowable composite was significantly higher (p < 0.05) than that of packable composite, while mechanical properties were significantly lower (p < 0.05). For cusp distance variation, no significant difference was observed in cavities restored through both restorative techniques, while temperature rise values spanned from 8.2 °C to 11.9 °C. Conclusions: No significant difference in cusp deflection between the two composites was observed according to both the restorative techniques. This result can be ascribed to the Young’s modulus suggesting that the packable composite is stiffer, while the flowable composite is more compliant, thus balancing the cusp distance variation. The light curing modality of 1000 mW/cm2 for 20 s can be considered thermally safe for the pulp chamber.

2008 ◽  
Vol 2 (1) ◽  
pp. 137-141 ◽  
Author(s):  
A Santini ◽  
C Watterson ◽  
V Miletic

The purpose of the study was to compare temperature rise during polymerisation of resin based composites (RBCs) with two LED light curing units (LCUs) compared to a halogen control light. Methods: Forty-five extracted molars, patients aging 11-18 years were used. Thermocouples (TCs) were placed in contact with the roof of the pulp chamber using a ‘split-tooth’ method. Teeth were placed in a water bath with the temperature of the pulp chamber regulated at 37°±1°C. Group 1 (control): Prismatics® Lite II (Dentsply Detrey, Konstanz, Germany), a halogen LCU, light intensity 500 mW/cm2. Group 2: Bluephase® ( Ivoclar Vivadent, Schaan, Liechtenstein), light intensity 1100 mW/cm2. Group 3:Elipar Freelight2 (3M ESPE, Seefeld, Germany), light intensity 1000 mW/cm2. Temperature changes were continuously recorded with a data logger connected to a PC. Results: Significantly higher temperature rise was recorded during bond curing than RBC curing in all 3 groups. (Halogen; p =0.0003: Bluephase; p=0.0043: Elipar; p=0.0002.). Higher temperatures were recorded during polymerisation of both Bond and RBC with both LED sources than with the halogen control. There was no significant difference between the two LED,LCUs (Bond:p=0.0279: RBC p=0.0562: Mann-Whitney). Conclusion: The potential risk of pulpal injury during RBC polymerisation is increased when using light-curing units with high energy output compared to low energy output light sources. The rise is greatest when curing bonding agent alone and clinicians are advised to be aware of the potential hazard of thermal trauma to the pulp when using high intensity light sources. However the mean temperature rise with all three units was below the limits normally associated with permanent pulp damage.


2021 ◽  
Author(s):  
KR Kantovitz ◽  
LL Cabral ◽  
NR Carlos ◽  
AZ de Freitas ◽  
DC Peruzzo ◽  
...  

SUMMARY The aim of this in vitro study was to quantitatively evaluate the internal gap of resin composites of high-and low-viscosity used in single- and incremental-fill techniques in Class I cavities exposed to thermal cycling (TC) using optical coherence tomography (OCT). Cavities of 4-mm depth and 3-mm diameter were prepared in 36 third molars randomly distributed into four groups, according to viscosity of restorative resin-based composite (high or low viscosity, all from 3M Oral Care) and technique application (bulk or incremental fill) used (n=9): RC, high-viscosity, incremental-fill, resin-based composite (Filtek Z350 XT Universal Restorative); BF, high-viscosity, bulk-fill, resin-based composite (Filtek One Bulk Fill); LRC, low-viscosity, incremental-fill, resin-based composite (Filtek Z350 XT Flowable Universal Restorative); and LBF, low-viscosity, bulk-fill, resin-based composite (Filtek Flowable Restorative). Single Bond Universal Adhesive system (3M Oral Care) was used in all the experimental groups. The incremental-fill technique was used for RC and LRC groups (2-mm increments), and a single-layer technique was used for BF and LBF groups, as recommended by the manufacturer. The internal adaptation of the resin at all dentin walls was evaluated before and after TC (5000 cycles between 5°C and 55°C) using OCT images. Five images of each restored tooth were obtained. Images were analyzed using ImageJ software that measured the entire length of the gaps at the dentin–restoration interface. The length of gaps (μm) was analyzed using two-way repeated measures ANOVA and the Tukey tests (α=0.05). There was a significant interaction between material types and TC (p=0.006), and a significant difference among all material types (p&lt;0.0001), before and after TC (p&lt;0.0001). Increased internal gaps at the dentin–restoration interface were noticed after TC for all groups. RC presented the lowest value of internal gap before and after TC, while LBF showed the highest values of internal gap after TC. In conclusion, TC negatively affected the integrity of internal gap, whereas high-viscosity, incremental-fill, resin-based composite presented better performance in terms of internal adaptation than low-viscosity, bulk-fill materials in Class I cavities.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Serdar Akarsu ◽  
Sultan Aktuğ Karademir

Objectives. The aim of this study was to compare the effects of different bulk-fill resin composites, polimerization modes, and the thickness of remaining dentin on the increase of intrapulpal temperature. Methods. Human-extracted upper premolar teeth (n = 10) were used to design a single-tooth model with remaining dentin thicknesses of 1 mm and 0.5 mm. Estelite Bulk-fill Flow (Tokuyama, Japan), Surefil SDR™ Flow (Dentsply Caulk, Brazil), Filtek Bulk-Fill Posterior (3M, USA), and SonicFill™ 2 Bulk-fill (Kerr, USA) composites were applied according to the manufacturer’s instructions. The standard and high modes of a light emitted diode (LED) light curing unit (LCU) (VALO™ Utradent, USA), were used for polymerization. In order to mimic the in vivo conditions of pulpal circulation, digital flowmetry (SK-600II, SK Medical, China) was used. Intrapulpal temperature rise was measured using K type thermocoupling (CEM DT 610B, Robosem Engineering, China). Data were analyzed using three-way variance analysis (ANOVA) and the independent t-test. Results. No significant statistical differences in intrapulpal temperature rise between low viscosity bulk-fill composites (SDR and Estelite) were found. The lowest intrapulpal temperature rise was found in groups which used the Filtek Bulk-fill composite. Decreases in the remaining dentin thickness increased the intrapulpal temperature rise. Significance. This study demonstrated that remaining dentin thickness, filler ratio of bulk-fill composites, and power and application time of the LED-LCU may affect intrapulpal temperature rise.


2020 ◽  
Vol 10 (22) ◽  
pp. 8041
Author(s):  
Roberto De Santis ◽  
Vito Gallicchio ◽  
Vincenzo Lodato ◽  
Sandro Rengo ◽  
Alessandra Valletta ◽  
...  

Background: Deep dental cavities can be restored through a single step according to the bulk-fill technique. Due to the great amount of resin to be cured, a main concern is the temperature rise occurring in the pulp chamber, potentially higher than that developed through the incremental layering technique. Temperature rise of bulk-fill composites have been evaluated. Methods: Bulk-fill composites, differing in material composition and viscosity, were used. Maximum temperature and temperature rate occurring in the composites were measured. Mesio-occlusal-distal cavities of human premolars were restored through the bulk-fill or the incremental layering techniques, and peak temperature and temperature rate occurring in the dentin, 1 mm below the cavity floor, were evaluated. Results: Temperature peak and temperature rise of flowable composites were significantly higher (p < 0.05) than packable composites. For both the techniques, higher temperature peaks were recorded in the dentin for flowable composites. Peak temperatures higher than 42 °C were recorded for the incremental layering technique considering flowable composites. Conclusions: For all the composites, the light curing modality of 1000 mW/cm2 for 20 s can be considered safe if the bulk-fill technique is performed. Instead, for the incremental layering technique, potentially dangerous temperature peaks have been recorded for flowable composites.


2021 ◽  
Vol 34 (2) ◽  
pp. 173-182
Author(s):  
Fabiana França ◽  
Jonathan Tenuti ◽  
Isabela Broglio ◽  
Lara Paiva ◽  
Roberta Basting ◽  
...  

The aim of this study was to compare low- and high-viscosity bulk-fill composites for Knoop microhardness (KHN), microtensile bond strength (MTBS) to dentin in occlusal cavities, and fracture strength (FS) in molars with mesialocclusal-distal restoration. Disk-shaped samples with different thicknesses (2 or 4 mm) of low-viscosity (SDR Flow, Dentsply) and high-viscosity bulk-fill composites (Filtek BulkFill, 3M ESPE; and Tetric-N Ceram Bulk Fill, Ivoclar Vivadent) were prepared for top and bottom KHN analysis (n=10). MTBS to dentin and fracture pattern was evaluated in human molars with occlusal cavities restored with (n=10): conventional nanocomposite (Z350XT, 3M ESPE), low-viscosity (Filtek Bulk-fill Flow, 3M ESPE) or high-viscosity bulk-fill composites (Filtek BulkFill). The FS and fracture pattern of human molar with mesial-occlusal-distal restorations submitted or not to thermomechanical cycling were investigated (n=10) using: intact tooth (control), and restoration based on conventional microhybrid composite (Z250, 3M ESPE), low-viscosity (SDR Flow) or high-viscosity bulk-fill composites (Filtek BulkFill). The data were submitted to split-plot ANOVA (KHN), one-way ANOVA (MTBS), two-way ANOVA (FS) followed by Tukey’s test (α=0.05). For KHN, there was no significant difference for the resin composites between the top and bottom. For MTBS, no significant differences among the materials were detected; however, the low-viscosity composite presented lower frequency of adhesive failures. For FS, there was no significant difference between composites and intact tooth regardless of thermomechanical cycling. Low- and high-viscosity bulk-fill composites have comparable microhardness and microtensile bond strength when used in occlusal restorations. Likewise, the bulk-fill composites present similar fracture strength in molars with mesio-occlusal-distal restorations.


2019 ◽  
Vol 44 (6) ◽  
pp. 625-636 ◽  
Author(s):  
ER Cerda-Rizo ◽  
M de Paula Rodrigues ◽  
ABF Vilela ◽  
SSL Braga ◽  
LRS Oliveira ◽  
...  

SUMMARY Objective: To analyze the shrinkage stress, bonding interaction, and failure modes between different low-viscosity bulk fill resin composites and conventional resin composites produced by the same manufacturer or a high-viscosity bulk fill resin composite used to restore the occlusal layer in posterior teeth. Methods & Materials: Three low-viscosity bulk fill resin composites were associated with the conventional resin composites made by the same manufacturers or with a high-viscosity bulk fill resin composite, resulting in six groups (n=10). The bonding interaction between resin composites was tested by assessing the microshear bond strength (μSBS). The samples were thermocycled and were tested with 1-mm/min crosshead speed, and the failure mode was evaluated. The post-gel shrinkage (Shr) of all the resin composites was measured using a strain gauge (n=10). The modulus of elasticity (E) and the hardness (KHN) were measured using the Knoop hardness test. Two-dimensional finite element models were created for analyzing the stress caused by shrinkage and contact loading. The μSBS, Shr, E, and KHN data were analyzed using the Student t-test and one-way analysis of variance. The failure mode data were subjected to chi-square analysis (α=0.05). The stress distribution was analyzed qualitatively. Results: No significant difference was verified for μSBS between low-viscosity bulk fill resin composites and conventional or high-viscosity bulk fill composites in terms of restoring the occlusal layer (p=0.349). Cohesive failure of the low-viscosity bulk fill resin composites was the most frequent failure mode. The Shr, E, and KHN varied between low-viscosity and high-viscosity resin composites. The use of high-viscosity bulk fill resin composites on the occlusal layer reduced the stress at the enamel interface on the occlusal surface. Conclusions: The use of high-viscosity bulk fill resin composites as an occlusal layer for low-viscosity bulk fill resin composites to restore the posterior teeth can be a viable alternative, as it shows a similar bonding interaction to conventional resin composites as well as lower shrinkage stress at the enamel margin.


2007 ◽  
Vol 8 (7) ◽  
pp. 29-37 ◽  
Author(s):  
Christopher Millen ◽  
Martyn Ormond ◽  
Gillian Richardson ◽  
Ario Santini ◽  
Vesna Miletic ◽  
...  

Abstract Aim The study compared pulp temperature rise during polymerization of resin-based composites (RBCs) using halogen and LED light-curing units (LCUs). Methods and Materials A total of 32 teeth extracted from patients aged 11-18 years were used in the study. Thermocouples placed on the roof of the pulp chamber using a novel ‘split-tooth’ method. In Group 1 a halogen LCU with a light intensity of 450 mWcm-2 was used and in Group 2, an LED LCU with a light intensity of 1100 mWcm-2 was used. The teeth were placed in a water bath with the temperature regulated until both the pulp temperature and the ambient temperature were stable at 37°C. Continuous temperature records were made via a data logger and computer. The increase in temperature from baseline to maximum was calculated for each specimen during the curing of both the bonding agent and the RBC. Results The rise in pulp temperature was significantly higher with the LED LCU than with the halogen LCU for bonding and RBC curing (p<0.05). The major rise in temperature occured during the curing of the bonding agent. During the curing of the RBC, rises were smaller. Conclusions Curing of bonding agents should be done with low intensity light and high intensity used only for curing RBC regardless of whether LED or halogen LCUs are used. Citation Millen C, Ormond M, Richardson G, Santini A, Miletic V, Kew P. A Study of Temperature Rise in the Pulp Chamber during Composite Polymerization with Different Light-curing Units. J Contemp Dent Pract 2007 November; (8)7:029-037.


2010 ◽  
Vol 13 (3) ◽  
pp. 132 ◽  
Author(s):  
RajeshA.V Ebenezar ◽  
R Anilkumar ◽  
R Indira ◽  
S Ramachandran ◽  
MR Srinivasan

2015 ◽  
Vol 85 (3) ◽  
pp. 381-385 ◽  
Author(s):  
Sabri Ilhan Ramoglu ◽  
Hilal Karamehmetoglu ◽  
Tugrul Sari ◽  
Serdar Usumez

ABSTRACT Objective:  To evaluate and compare intrapulpal temperature rise with three different light-curing units by using a study model simulating pulpal blood microcirculation. Materials and Methods:  The roots of 10 extracted intact maxillary central incisors were separated approximately 2 mm below the cement-enamel junction. The crowns of these teeth were fixed on an apparatus for the simulation of blood microcirculation in pulp. A J-type thermocouple wire was inserted into the pulp chamber through a drilled access on the palatal surfaces of the teeth. Four measurements were made using each tooth for four different modes: group 1, 1000 mW/cm2 for 15 seconds; group 2, 1200 mW/cm2 for 10 seconds; group 3, 1400 mW/cm2 for 8 seconds; and group 4, 3200 mW/cm2 for 3 seconds. The tip of the light source was positioned at 2 mm to the incisor's labial surface. Results:  The highest temperature rise was recorded in group 1 (2.6°C ± 0.54°C), followed by group 2 (2.57°C ± 0.62°C) and group 3 (2.35°C ± 0.61°C). The lowest temperature rise value was found in group 4 (1.74°C ± 0.52°C); this value represented significantly lower ΔT values when compared to group 1 and group 2 (P  =  .01 and P  =  .013, respectively). Conclusions:  The lowest intrapulpal temperature rise was induced by 3200 mW/cm2 for 3 seconds of irradiation. Despite the significant differences among the groups, the temperature increases recorded for all groups were below the critical value of 5.6°C.


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