fracture resistance using fibre reinforced materials in direct restoration

fracture resistance using fibre reinforced materials in direct restoration

1. Comparative Evaluation of Fracture Resistance of Posterior Teeth Restored Using Three New Composite Materials: An In Vitro Study Kamath AK, Kudva AR, Eram A, Sreekantan PM, Kini S. Comparative Evaluation of Fracture Resistance of Posterior Teeth Restored Using Three New Composite Materials: An In Vitro Study. World Journal of Dentistry. 2023 Sep 1;14(7):608-12. Dr. INDUMATHI (II MDS) CONSERVATIVE DENTISTRY & ENDODONTICS

2. introduction “Healthy teeth are rarely fractured by mastication stress; The fracture usually occurs in tooth weakened due to caries” Bassett RW, Ingraham R, Koser JR. An atlas of cast gold procedures. Department of Operative Dentistry, University of Southern California, School of Dentistry; 1964.

3. Mondelli RF, Ishikiriama SK, Oliveira Filho OD, et al. Fracture resistance of weakened teeth restored with condensable resin with and without cusp coverage. J Appl Oral Sci 2009;17:161–165. DOI: 10.1590/s1678- 77572009000300006

4. fracture Around 10% of complete cusp fractures of posterior teeth occur in teeth without restorations. Bader JD, Shugars DA, Martin JA. Risk indicators for posterior tooth fracture. J Am Dent Assoc 2004;135(7):883–892. DOI: 10.14219/ jada . archive.2004.0334

5. AIM The main aim of this study was to evaluate the fracture resistance of the premolar teeth which was restored using three new composite materials.

6. 3M BULK FILL FILTEK TM To improve the efficacy of composite resin restorations, bulk-fill composites were introduced. They were placed in 4 mm increments in the posterior area and were found to have stronger physical and mechanical attributes to withstand masticatory loads. They also resulted in shorter treatment periods thereby reducing the chance of moisture or air contamination. Some studies have observed that they decreased cuspal deflection and increased light transmission. In another study, it was also proved that composite has higher tensile strength when compared to glass ionomer cement and amalgam. Walter R. Bulk-fill flowable composite resins. J Esthetic Resto Dent 2013;25(1):72–76. DOI: 10.1111/jerd.12011

7. Wear of Bulk-fill Composite Resins After Thermo-mechanical Loading Alsahafi TA, Walter R, Nunes M, Sulaiman TA. Wear of Bulk-fill Composite Resins After Thermo-mechanical Loading. Operative Dentistry. 2023 May 23;2023(48-X):000-. Objective:  To evaluate and compare the volumetric wear (mm3) of bulk-fill composite resins to a conventional composite resin and enamel after thermo-mechanical loading. Methods and materials:  Five composite resins (n=10) were evaluated: four bulk-fill composite resins ( Filtek One Bulk Fill [3M Oral Care], Tetric EvoCeram Bulk Fill [ Ivoclar Vivadent ], Tetric PowerFill [ Ivoclar Vivadent ], SonicFill 3 [Kerr Corp]); and one conventional composite resin ( Filtek Supreme Ultra [3M Oral Care]). Conclusions:  Bulk-fill composite resins showed higher wear resistance than the conventional composite resin , and both types of composite resin were not as wear-resistant as enamel.

8. EVERX POSTERIOR A fiber-reinforced form of conventional dental composites; recently introduced with the objective of improving the resistance to occlusal load with short fibers. Contains E glass fibres-17µm in diameter, 1-2mm in length. The resin matrix contains crosslinked bis-glycidyl methacrylate, Triethylene glycol dimethacrylate , and linear polymethyl methacrylate forming a polymer matrix that improves composite toughness and provides excellent bonding properties. Garoushi S, Säilynoja E, Vallittu PK, et  al. Physical properties and depth of cure of a new short fiber reinforced composite. Dent Mater 2013;29(8):835–841. DOI: 10.1016/j.dental.2013.04.016

9. Comparative Evaluation of Fracture Resistance of Fiber-Reinforced Composite and Alkasite Restoration in Class I Cavity Rajaraman G, Eagappan AS, Bhavani S, Vijayaraghavan R, Harishma S, Jeyapreetha P. Comparative evaluation of fracture resistance of fiber -reinforced composite and alkasite restoration in class I cavity. Contemporary Clinical Dentistry. 2022 Jan 1;13(1):56-60. Aim:  The aim of this study was to evaluate and compare the fracture resistance of two such advanced restorative materials, namely EverX Posterior, a fiber-reinforced composite and Cention N, an alkasite material in a Class I Cavity. Materials and methods:  Forty intact, caries-free human maxillary premolar teeth extracted for orthodontic purposes were divided randomly into four groups of 10 teeth each. Group I were unprepared teeth (intact teeth); Group II were unrestored teeth with class I cavity; Group III were teeth restored with fiber-reinforced composite (EverX Posterior); and Group IV were teeth restored using alkasite material ( Cention N). Fracture resistance was recorded for all samples using a universal testing machine. Results:  Higher fracture resistance was recorded in intact teeth group followed by EverX Posterior, Cention N and unrestored teeth, respectively. The teeth restored with EverX Posterior showed higher mean fracture resistance to fractures than those restored with Cention N. Teeth restored with EverX Posterior showed no significant difference in mean fracture resistance from Intact teeth while restored teeth with Cention N and unrestored teeth did. Conclusion:  Fracture resistance of EverX Posterior was comparable to that of the natural tooth and was higher as compared to Cention N.

10. SMART DENTIN REPLACEMENT SDR is a single-component, fluoride-containing restorative material extremely easy to handle and can be bulk-filled. Smart dentin replacement (SDR) has claimed to enhance the compressive strength owing to its increased filler particle. SDR is a flowable base material with low stress that can be layered up to 4 mm thick. In the present work, the entire cavity was restored with SDR. The filler content of SDR is 68%. Badr SB, Ibrahim MA, El Banna M. Compressive strength and compressive fatigue limit behavior of two fluoride releasing materials. Advan Med Sci 2013;2(3):30–36.

11. Effect of proximal box elevation on fracture resistance and microleakage of premolars restored with ceramic endocrowns Zhang H, Li H, Cong Q, Zhang Z, Du A, Wang Y. Effect of proximal box elevation on fracture resistance and microleakage of premolars restored with ceramic endocrowns . Plos one. 2021 May 26;16(5):e0252269. Objective:  To evaluate the influence of PBE on fracture resistance and gingival microleakage of premolars with endodontic access cavities following ceramic endocrown . Methods:  Eighty sound maxillary premolars with standardized Class II cavities on mesial surfaces were randomly assigned to four groups (n = 20 in each group)  Group E4 (supragingival group), with proximal margins located in enamel, 1 mm above the CEJ, was used as the positive control. For margin elevation of the proximal cavities, bulk-fill Smart Dentin Replacement (SDR), a visible light cured resin composite, was applied in group E1, and conventional resin composite (3M Z350 XT, a light-activated composite) was placed in group E2. Group E3 was only treated with a ceramic crown and served as the negative control. Results:  A higher fracture resistance value was observed in PBE groups E1 and E2 , regardless of the materials used (P = 0.038, and 0.010, respectively, vs E3), and fracture resistance in group E1 was higher than that in group E2. 

12. However, a comprehensive study of all the new composite materials is required to identify the best-case application of these new materials released in the market. In the present study, a comparison of the fracture resistance of the premolar teeth restored with the newly introduced everX posterior, SDR, and Filtek bulk-fill composite materials are carried out to determine the best restorative material.

13. Materials and methods The ethical clearance was received by the Yenepoya (Deemed-to-be-University), Mangaluru , Karnataka, India, Institutional Ethics Committee with the number YUEC258/11/12/2014. This study was carried out in a period of 6 months from the time of obtaining ethical clearance. Extracted upper maxillary premolars from the Department of Oral and Maxillofacial Surgery, Yenepoya Dental College, Yenepoya (Deemed-to-be-University), Mangaluru , Karnataka, India and other private clinics were used in this study

14. .. INCLUSION CRITERIA sound maxillary first and second premolars recently extracted carious teeth, restored teeth, grossly decayed teeth, fractured teeth, and old extracted teeth EXCLUSION CRITERIA

15. Fracture resistance was calculated using Universal Testing Machine Axial compressive load

16. CAVITY PREPARATION NO PREPARATION FOR CONTROL GROUP….

17. PREPARATION GROUP III

18. GROUP IV PREPARATION Group IV cavities were prepared according to the procedure and filled with SDR restorative material. GROUP V Following the guidelines for group II, the cavities in group V were prepared and filled with 3M bulk-fill ( Filtek ™). The (SHOFU) composite was used for the polishing and finishing steps and paste was used for the finer surface.

19. LABORATORY TESTING

20. TOOTH FRACTURED ON COMPRESSIVE LOAD

21. STATISTICAL ANALYSIS The data were submitted, and statistical analysis was done with the help of one-way analysis of variance for multiple comparisons followed by post hoc Tukey test for inter and intragroup comparisons.

22. RESULTS The intragroup analysis showed the mean value of group III (1,209.33) is the highest followed by group I (1,196), group IV (1,030), group V (1,014), and least in group II (720.6). This difference is statistically significant with a test value of 84.156 and a p-value of < 0.001. The intergroup analysis with the post hoc Tukey test showed statistically significant results within all groups except between groups I and III and IV and V with a value of (0.992). In this study the results showed the premolar tooth exhibited excellent fracture toughness with everX posterior proving to be the best material followed by SDR and 3M bulk-fill composite.

23. Intergroup COMPARISION

24. INTRAGROUP COMPARISION

25. At the tooth structure/restorative interface, all materials are fractured. In this investigation, MOD cavities were created to mimic a scenario that is frequently seen in clinical settings and has been faithfully replicated in other clinical trials. Long cusps are a common result of MOD cavity preparations; therefore, a restoration is required that not only restores the tooth’s original structure but also improves the remaining tooth’s fracture resistance and encourages efficient marginal sealing. This indicated that the restoration/tooth structure interface has the weakest bond. For the purpose of strengthening teeth, adhesive materials have been deemed useful. These materials help in adhering the composite as well as give good retention properties of the restored tooth. discussion Sorrentino R. Effect of post retained composite restorations of mesialocclusal -distal cavities on the fracture resistance of endodontically treated teeth. J Adhes Dent 2007;9(1):49–56.

26. Based on the E-glass fiber and barium borosilicate glass filler, this study demonstrated that everX posterior has the highest fracture resistance among the composite materials used in this study. The total inorganic fiber and filler content is 77% by weight. EverX posterior being an anisotropic material, its properties vary depending on the dimension in which they are observed. When fibers are orientated on a plane, the horizontal shrinkage, which is controlled by the direction of the fibers, will be different from the vertical shrinkage. As a result, the everX posterior material cannot shrink along the length of the fibers during polymerization. discussion Bremer BD, Geurtsen W. Molar fracture resistance after adhesive restoration with ceramic inlays or resin-based composites. Am J Dent 2001;14(4):216–220.

27. discussion EverX posterior performed exceptionally well in the analysis. The orientation and the presence of fibers can be the main reason for the strength of the material (quote for introstrength of material). In general, the study demonstrated the usefulness of all the restorative materials to strengthen the teeth with slightly better outcomes with everX posterior material. Garoushi SK, Hatem M, Lassila LV, et  al. The effect of short fiber composite base on microleakage and load-bearing capacity of posterior restorations. Acta Biomater Odontol Scand 2015;1(1):6–12. DOI: 10.3109/23337931.2015.1017576

28. discussion Thus, both the material and type of restoration can influence the quality of the reinforcement. Silva et al. in a study concluded that the type of load application device influences significantly the behavior of the teeth restoration complex during mechanical fracture resistance test. In a study done by Jagadish and Yogesh, which compared dentin bonding restorations to glass cermet, and silver amalgam, dentin bonding restorations produced the best fracture toughness. Future directions for the clinicians are that more trials will be needed to confirm the material’s performance and longevity. The outcome of this study basically implies that teeth under functional load can fracture but materials like everX posterior, SDR, and 3M bulk-fill can provide better fracture toughness compared to previously used materials.

29. CONCLUSION Within the limitations of this study, everX posterior increased the resistance to fracture almost similar to that of sound teeth indicating that everX posterior was the best material among the three materials used. SDR and 3M bulk-fill have shown lower fracture resistance than the natural unprepared tooth. In this study, the newer tooth-colored restorative materials showed good fracture toughness and better biocompatibility compared to previously used dental materials.

30. CRITICAL EVALUATION Fracture resistance is an important property directly related to cracking.  Even though  in vitro  studies are not an actual reproduction of a typical chewing stroke, they provide valuable information on the weakest component of restored tooth. Clinically, masticatory forces are of a relatively consistent magnitude and contribute to a different pattern of fracture when it occurs. To what extent MOD is prepared to weaken the remaining tooth structure ? There was no mention of standardization for proximal box preparation Drawbacks

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