Journal of Conservative Dentistry
Home About us Editorial Board Instructions Submission Subscribe Advertise Contact e-Alerts Login 
Users Online: 414
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size
 


 
Table of Contents   
ORIGINAL ARTICLE  
Year : 2019  |  Volume : 22  |  Issue : 3  |  Page : 287-291
Comparison of the fracture resistance of three different recent composite systems in large Class II mesio-occlusal distal cavities: An in vitro study


Department of Conservative Dentistry and Endodontics, Daswani Dental College and Research Centre, Kota, Rajasthan, India

Click here for correspondence address and email

Date of Submission09-May-2018
Date of Decision15-Jun-2018
Date of Acceptance06-Jun-2019
Date of Web Publication03-Jul-2019
 

   Abstract 

Background: The present study was undertaken to evaluate the most suitable recent restorative material for extensively mutilated teeth.
Aim: This study aims to evaluate and compare the fracture resistance of maxillary premolars with Class II mesio-occlusal distal (MOD) cavities restored with recent Ever X posterior, bulk-fill composite, and Estelite sigma quick composite systems.
Materials and Methods: Sixty human maxillary premolars were selected. Fifteen intact teeth served as positive control (Group 1). MOD cavities were prepared in the remaining 45 teeth with standardized dimensions and were randomly divided into three experimental groups (Group 2, 3, and 4) (n = 15). Teeth in Group 2, 3, and 4 were reinforced with 3M ESPE Filtek Bulk-fill posterior, GC Ever X posterior, and Tokuyama Estelite sigma quick composites, respectively. Fracture resistance was measured in Newton (N).
Results: Group 4 (1432.60 N) showed the highest mean fracture resistance followed by Group 3 (1326.20 N), Group 1 positive controls (1288.53 N), and Group 2 (946.66N), respectively. One-way analysis of variance (ANOVA) test revealed a statistically significant difference between all the groups (P = 0.005). Post hoc Tukey test revealed a statistically significant difference in mean fracture resistance between the Group 2 and Group 4 (P = 0.004), as well as between the Group 2 and Group 3 (P = 0.033). However, there were no significant differences among the other groups.
Conclusion: Among the experimental groups, Estelite sigma quick composite showed the highest fracture resistance. Statistically, a significant difference was seen between all groups.

Keywords: Bulk fills; e glass fibers; fracture resistance; mesio-occlusal distal cavities; spherical supranano fillers

How to cite this article:
Hada YS, Panwar S. Comparison of the fracture resistance of three different recent composite systems in large Class II mesio-occlusal distal cavities: An in vitro study. J Conserv Dent 2019;22:287-91

How to cite this URL:
Hada YS, Panwar S. Comparison of the fracture resistance of three different recent composite systems in large Class II mesio-occlusal distal cavities: An in vitro study. J Conserv Dent [serial online] 2019 [cited 2019 Oct 23];22:287-91. Available from: http://www.jcd.org.in/text.asp?2019/22/3/287/262012

   Introduction Top


Restoration of extensively carious teeth is one of the biggest challenges in dentistry. Many types of research and advancements on the molecular level are going on to overcome the shortcomings such as polymerization shrinkage, microleakage, water sorption, and technique sensitivity, leading to the evolution of composites with improved properties.[1]

Recent materials such as fiber-reinforced composites, bulk-fill composites, and higher filler content composites are introduced with improved handling properties, reduced polymerization shrinkage, and increased fracture toughness.

Recently, time-saving composites are introduced which can be placed in 4–5 mm bulk and cured in one step. Rheology of bulk fills is such that it allows better adaptation to the cavity walls with self-leveling effect.[2]

Fiberreinforced Ever X posterior composite consists of the combination of Eglass fibers and barium glass filler, fiber length in millimeter scale is 1–2 mm.[2] Within a tough polymer matrix fibers helps in stopping the crack progression same as the function of dentine, rendering it a perfect material of choice in large size cavities(MOD).[3] It is basically a dentine replacement composite and needs to be covered proximally and occlusally with conventional composite simulating enamel coverage.[4]

Group of new composites Estelite sigma quick with higher filler loading and spherical supranano zirconia and silica fillers not just impart improved physical properties but also made it esthetically demanding, quick curing time enhance the handling characteristics.[5] Total filler content in Ever X posterior is 53.6% by weight.[21],[23]

Hence, this study aims to evaluate the fracture toughness of the recent composite materials in severely weakened maxillary premolars with mesio-occlusal distal (MOD) cavities. The objective of the study was to evaluate the fracture resistance of all the three materials and to find which restorative material will provide maximum fracture resistance.

The null hypothesis tested will be that there will be no difference in the fracture resistance of intact teeth and those restored with different composite materials.


   Materials and Methods Top


Sixty human maxillary premolars collected from department oral and maxillofacial surgery which was extracted for orthodontic reason, were used in the study. Power and the sample size of the study were calculated by IBM ® SPSS ® 21 SOFTWARE (IBM, Hong Kong). All the specimens were scaled to remove the adhering soft tissue and calculus and were stored in physiologic saline. Fully erupted teeth with mature apices, intact enamel and dentine without any carious lesion, restorations, and developmental defects were included. Teeth with open apices or resorption, previous restorations, or with any anatomical variation were excluded from the study.

Fifteen intact teeth were used as positive controls (Group 1). Standardized MOD cavities was prepared using a tungsten carbide straight fissure bur (FG 172, KERR Haw, Canada) in high-speed water-cooled hand piece, bur was changed after every 10 cavity preparations. Dimensions were 2 mm ± 0.2 mm pulpal width, 1.5 mm ± 0.2 mm gingival width, and 2 mm ± 0.2 mm buccolingual width and are verified using periodontal probe.[6] Facial and lingual walls of the occlusal segment were prepared parallel to each other with the cavosurface angle at 90° [Figure 1] and [Figure 2].
Figure 1: Cavity preparation mesial review

Click here to view
Figure 2: Cavity preparation occlusal view

Click here to view


Prepared cavities were air-dried, and COLTENE Swiss Tec etchant was used for 10 s, and cavities were rinsed for 30 s and air-dried.

3M ESPE Single Bond Universal bonding agent was applied and cured for 20 s with Dentsply Spectrum curing light. Tofflemire matrix band was applied for a further composite restoration.

Subsequently, teeth were randomly divided into three groups (n = 15).

Group 2: Teeth restored with Filtek 3M ESPE bulk fill

Bulk-fill posterior composite was placed in bulk without any incremental technique and cured for 30 s [Figure 3].
Figure 3: Restoration with bulk-fill posterior

Click here to view


Group 3: Teeth restored with fiber-reinforced composite GC Ever X posterior

In this case, walls of the MOD cavities were built by microhybrid Coltene Swiss Tec composite followed by placement of Ever X posterior composite in the core. The restoration was completed by placing a 0.5 mm layer of microhybrid composite on the occlusal surface [4] [Figure 4].
Figure 4: Restoration with Ever X posterior

Click here to view


Group 4: Teeth restored with TOKUYAMA Estelite sigma quick

Estelite sigma quick composite was placed by incremental technique and cured for 10 s for each increment [Figure 5].
Figure 5: Restoration with Estelite sigma quick

Click here to view


Manufacturer's instructions were followed while placing and curing the composites.

Thermocycling (SD Mechatronik, Germany thermocycler) was carried out 500 cycles at 5°C ± 2°C–55°C ± 2°C with 30 s dwell time and 5 s transfer time. Then, the specimens were stored in an incubator (Bioline technology, India) at 37°C and 100% humidity for 24 h. Teeth were mounted in square blocks of cold cure acrylic resin 2 cm in dimensions up to 1.5 mm apical to the cement–enamel junction. A layer of light body elastomeric impression material was applied around the root surface to simulate the periodontal ligament. The fracture resistance of the teeth was measured using an Instron India universal testing machine (model 1011). Each specimen was subjected to compressive loading using a 5 mm round diameter stainless steel ball at a strain rate of 2 mm/min. The ball should contact the inclined planes of the facial and palatal cusps beyond the margins of the restoration, which will simulate the tendency of the masticatory forces deflecting the cusps under stress. The force necessary to fracture the specimen was recorded in Newton (N), and data obtained were tabulated and subjected to the statistical analysis using IBM SPSS Statistics professional software.


   Results Top


Highest mean fracture resistance was observed with Group 4 Estelite sigma quick (1432.60 N) followed by Group 3 Ever X posterior (1326.20 N), Group 1 Intact teeth (1288.53 N), and Group 2 bulkfill posterior composite (946.66N) [Figure 6]. One-way ANOVA test [Table 1] and [Table 2] revealed a statistically significant difference (P = 0.005) between the groups. On intergroup comparisons, Post hoc Tukey test [Table 3] revealed that there is a statistically significant difference in mean fracture resistance between the Group 2 and Group 4 (P = 0.004), as well as between the Group 2 and Group 3 (P = 0.033). However, there were no differences between the other groups.
Figure 6: Graphical representation of comparison of mean fracture resistance of composites

Click here to view
Table 1: Mean fracture resistance in Newton (N) in all four groups

Click here to view
Table 2: Fracture resistance analysis of variance test

Click here to view
Table 3: Multiple comparisons using post hoc Tukey test

Click here to view



   Discussion Top


Tokuyama Estelite sigma quick is the preferred material for restoring extensive cavities with the highest mean fracture resistance (1432.60 N) followed by Ever X Posterior (1326.20 N), positive controls (1288.53 N), and Bulk-fill group (946.66N). Hence, our null hypothesis has got rejected.

Fracture is a complete or incomplete break in a material resulting from the application of excessive force.[7] Fracture resistance is directly related to the stoppage of the crack propagation. Masticatory forces have a tendency to deflect cusps, and composites decrease the deformation of the cusps under masticatory load.[8],[9]

The variation in strength between different composites may be explained due to the differences in the chemical composition of their matrix, filler content, filler size, and distribution.[9],[10] Thus, a reduction in size and increase in the volume of fillers are directly proportional to an increase in compressive strength and surface hardness.[10],[11]

High filler loading increases the physical and handling properties of the composites, new adhesive materials not only seal the margin but also increase the retention and resistance properties of the restored tooth.[12] Recent nanofiller technology with nanometric fillers impregnated in nanoclusters leads to high filler loading resulting in an increase in high compressive strength and flexural strength.[13],[14]

Bulk filling all of the tooth preparation with a composite at one time has obvious advantages for both patients and practitioners. The manufacturers claim that the bulk-fill materials can achieve a depth of cure of 6 mm.[15],[16] Bulk-fill technology not only results in fewer voids in the mass of the material since all of it is placed at one time but also would be faster than placing numerous increments.

Filtek™ Bulk Fill Posterior contains two novel methacrylate monomers that, in combination, act to lower polymerization stress. A high molecular weight aromatic urethane dimethacrylate decreases the number of reactive groups in the resin. This helps to moderate the volumetric shrinkage. The addition–fragmentation monomers contain a third reactive site that cleaves through a fragmentation process during polymerization. This process provides a mechanism for the relaxation of the developing network and subsequent stress relief. The fragments, however, still retain the capability to react with each other or with other reactive sites of the developing polymer.[17]

Radical-amplified photopolymerization initiator (RAP technology) is used in Estelite sigma quick. The initiator balances the high polymerization activity needed to cure the resin with short exposure times (one-third of that required by conventional composites) and requires exposures of 10 s or less. To achieve high esthetic qualities, it has a suprananofillers 0.2-μm mono-dispersing spherical filler (Si-Zr). Particle diameters of 0.2 μm are known to produce the best balance of material properties and esthetics. Estelite sigma quick itself resists wearing without causing unusual wear in opposing teeth. It resists absorbing stains from substances such as coffee better than conventional products.[19] It is 82% filled by weight, which allows it to have excellent strength and durability to withstand the demands of the posterior dentition and the harsh environment of the oral cavity.[18]

Fibers incorporated into a composite material greatly enhances its mechanical property. The fibers present helps in stopping crack propagation when the stress is transferred from the matrix to the fibers.[20] Ever X posterior containing E-glass fibers of 1–2 mm in length impregnated within the nanohybrid composite could be used in 4 mm increment. The difference in fracture toughness between materials may be due to the inorganic filler loading – 76.5% by weight in bulk-fill composites, 53.6% in Ever X posterior, and 82% in Estelite sigma quick. The highest filler loading in Tokuyama Estelite sigma quick provides excellent strength and durability.

The present results were obtained in optimized laboratory settings; however, clinical conditions are not similar and the aspects such as insertion and handling could have a potential effect on the mechanical properties of the materials and their performance.

Maxillary premolars were chosen as they are more prone to fracture due to the anatomical shape with steep cuspal inclines which leads to cuspal separation during mastication.[4] MOD cavities were prepared in the teeth as these are considered to be the worst in terms of fracture resistance.[22]

Any relevant study could not be found comparing bulk-fill posterior composite, Ever X posterior along with Estelite sigma quick, and hence, the results of the study cannot be substantiated with those of any other studies.


   Conclusion Top


Within the limitations of this study, maximum fracture resistance is shown by the Tokuyama Estelite sigma quick composite.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
   References Top

1.
Cötert HS, Sen BH, Balkan M.In vitro comparison of cuspal fracture resistances of posterior teeth restored with various adhesive restorations. Int J Prosthodont 2001;14:374-8.  Back to cited text no. 1
    
2.
Moorthy A, Hogg CH, Dowling AH, Grufferty BF, Benetti AR, Fleming GJ. Cuspal deflection and microleakage in premolar teeth restored with bulk-fill flowable resin-based composite base materials. J Dent 2012;40:500-5.  Back to cited text no. 2
    
3.
Aniket K, Shweta T, Rajkumar B, Vishesh G. Comparative evaluation of fracture resistance of fibre reinforced composite, flowable composite and a core build-up material. Int J Curr Res 2016;6:378-81.  Back to cited text no. 3
    
4.
Bilgi PS, Shah NC, Patel PP, Vaid S. Fracture resistance of endodontically treated teeth restored with nanohybrid, silorane, and fibre reinforced composite. J Conserv Dent 2016;4:364-367.  Back to cited text no. 4
    
5.
Estelite Sigma Quick 5-year Clinical Performance Report. The Dental Advisor; 2014.  Back to cited text no. 5
    
6.
St. Georges AJ, Sturdevant JR, Swift EJ Jr., Thompson JY. Fracture resistance of prepared teeth restored with bonded inlay restorations. J Prosthet Dent 2003;89:551-7.  Back to cited text no. 6
    
7.
Schultrich B. Strength of cemented carbides, in mechanical properties of brittle materials, in modern theories and experimental evidence. J Biomed Res 2011;25:418-24.  Back to cited text no. 7
    
8.
Jagadish S, Yogesh BG. Fracture resistance of teeth with class 2 silver amalgam, posterior composite, and glass cermet restorations. Oper Dent 1990;15:42-7.  Back to cited text no. 8
    
9.
Johnson EW, Castaldi CR, Gau DJ, Wysocki GP. Stress pattern variations on operatively prepared human teeth studied by three- dimensional photo-elasticity. J Dent Res 1968;97:1075-8.  Back to cited text no. 9
    
10.
Bonilla ED, Mardirossian G, Caputo AA. Fracture toughness of posterior resin composites. Quintessence Int 2001;32:206-10.  Back to cited text no. 10
    
11.
Adabo GL, dos Santos Cruz CA, Fonseca RG, Vaz LG. The volumetric fraction of inorganic particles and the flexural strength of composites for posterior teeth. J Dent 2003;31:353-9.  Back to cited text no. 11
    
12.
Sabbagh J, Ryelandt L, Bachérius L, Biebuyck JJ, Vreven J, Lambrechts P, et al. Characterization of the inorganic fraction of resin composites. J Oral Rehabil 2004;31:1090-101.  Back to cited text no. 12
    
13.
Willems G, Lambrechts P, Braem M, Celis JP, Vanherle G. A classification of dental composites according to their morphological and mechanical characteristics. Dent Mater 1992;8:310-9.  Back to cited text no. 13
    
14.
Bremer BD, Geurtsen W. Molar fracture resistance after adhesive restoration with ceramic inlays or resin-based composites. Am J Dent 2001;14:216-20.  Back to cited text no. 14
    
15.
Mitra SB, Wu D, Holmes BN. An application of nanotechnology in advanced dental materials. J Am Dent Assoc 2003;134:1382-90.  Back to cited text no. 15
    
16.
de Moraes RR, Gonçalves Lde S, Lancellotti AC, Consani S, Correr-Sobrinho L, Sinhoreti MA, et al. Nanohybrid resin composites: Nanofiller loaded materials or traditional microhybrid resins? Oper Dent 2009;34:551-7.  Back to cited text no. 16
    
17.
Czasch P, Ilie N.In vitro comparison of mechanical properties and degree of cure of bulk fill composites. Clin Oral Investig 2013;17:227-35.  Back to cited text no. 17
    
18.
Ilie N, Stark K. Curing behaviour of high-viscosity bulk-fill composites. J Dent 2014;42:977-85.  Back to cited text no. 18
    
19.
3M FiltekTM Bulk Fill. Posterior Restorative. Technical Product Profile. Available from: http://multimedia.3m.com/mws/media/984592O/filtek-bulk-fill-posterior-re. [Last accessed on 2018 May 15].  Back to cited text no. 19
    
20.
Tokuyama Sigma Estellite Quick. Technical Product Profile. Available from: https://www.tokuyama-us.com/wp-content/uploads/resources/Estelite-Sigma-Quick-Product.pdf. [Last accessed on 2018 May 11].  Back to cited text no. 20
    
21.
Jain A, Sonkusre S, Tavane PN, Singh A, Gupta P, Nayak BG, et al. Evaluation of microleakage between silorane 2011;42:579-87.  Back to cited text no. 21
    
22.
Abouelleil H, Pradelle N, Villat C, Attik N, Colon P, Grosgogeat B, et al. Comparison of mechanical properties of a new fiber reinforced composite and bulk filling composites. Restor Dent Endod 2015;40:262-70.  Back to cited text no. 22
    
23.
GC Ever X Posterior. Technical Product Profile. Available from: https://www.tokuyama-us.com/wp-content/uploads/resources/Estelite-Sigma-Quick-Product.pdf. [Last accessed on 2018 May 11].  Back to cited text no. 23
    

Top
Correspondence Address:
Prof. Yajuvender Singh Hada
Department of Conservative Dentistry and Endodontics, Daswani Dental College and Research Centre, IPB-19, RIICO Institutional Area, Ranpur, Kota - 324 009, Rajasthan
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/JCD.JCD_225_18

Rights and Permissions


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

Top
 
 
 
  Search
 
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  
 


    Abstract
   Introduction
    Materials and Me...
   Results
   Discussion
   Conclusion
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed949    
    Printed13    
    Emailed0    
    PDF Downloaded353    
    Comments [Add]    

Recommend this journal