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VOLUME 25 , ISSUE 1 ( January, 2024 ) > List of Articles


In Vitro Microleakage and Fracture Resistance of “Infinity Edge” and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites

Jill C Watson, Wen Lien, Christopher J Raimondi, Stephen C Arnason, Kraig S Vandewalle

Keywords : Composite restorations, Fracture resistance, Infinity edge, Microleakage

Citation Information : Watson JC, Lien W, Raimondi CJ, Arnason SC, Vandewalle KS. In Vitro Microleakage and Fracture Resistance of “Infinity Edge” and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites. J Contemp Dent Pract 2024; 25 (1):3-9.

DOI: 10.5005/jp-journals-10024-3628

License: CC BY-NC 4.0

Published Online: 17-02-2024

Copyright Statement:  Copyright © 2024; The Author(s).


Aim: This study aimed to evaluate the marginal microleakage and maximum occlusal fracture loads and fracture modes of two novel class II preparation designs, “infinity edge” and the “2.5 mm cusp reduction” preparations as compared to a traditional class II preparation without cuspal involvement. Materials and methods: Thirty extracted human mandibular molars were prepared for moderate-sized class II restorations with extensions into all occlusal grooves. Of these, ten class II preparations served as control. Ten were modified for a 2.5 mm even reduction of the cusps adjacent to the interproximal box. An additional 10 preparations were modified with an “infinity edge” bevel on the interproximal and occlusal portions. All teeth were restored utilizing a flowable bulk-fill composite in the apical portion of the interproximal box and 2–4 mm of heated bulk-fill composite in one increment for the remainder. All groups were cyclic loaded and thermocycled, then imaged with microcomputed tomography (µCT) before and after infiltration with a silver nitrate solution. Images were subtracted to obtain volumetric measurements of microleakage and reported as a percentage of the total volume from the apical extent of the proximal box. All groups were loaded to failure and fracture load and mode were recorded. Results: No significant differences were found in microleakage volume as a percentage of total tooth volume; however, the “infinity edge” group had significantly greater microleakage in the proximal box compared to the traditional class II group. No significant differences were found in fracture load or mode between the groups. Conclusion: Traditional class II, 2.5 mm cuspal reduction, and “infinity edge” preparation designs have similar fracture loads as well as volumes of microleakage; however, an “infinity edge” preparation has a higher ratio of microleakage in the proximal box. Clinical significance: Clinicians should carefully consider the use of “infinity edge” margins, particularly on dentin in the apical extent of the proximal box.

  1. Bernardo M, Luis H, Martin MD, et al. Survival and reasons for failure of amalgam versus composite posterior restorations placed in a randomized clinical trial. J Am Dent Assoc 2007;138(6):775–783. DOI: 10.14219/jada.archive.2007.0265.
  2. Fennis W, Kuijs R, Kreulen C, et al. Fatigue resistance of teeth restored with cuspal-coverage composite restorations. Inter J Prosthodont 2004;17(3):313–317. PMID: 15237878.
  3. Kuijs R, Fennis W, Kreulen C, et al. A randomized clinical trial of cusp-replacing resin composite restorations: Efficiency and short-term effectiveness. Inter J Prosthodont 2006;19(4):349–354. PMID: 16900817.
  4. Panahandeh N, Torabzadeh H, Ziaee N, et al. The effect of composite thickness on the stress distribution pattern of restored premolar teeth with cusp reduction. J Prosthodont 2017;26(5):440–445. DOI: 10.1111/jopr.12422.
  5. Arbildo–Vega HI, Lapinska B, Panda S, et al. Clinical effectiveness of bulk-fill and conventional resin composite restorations: Systematic review and meta-analysis. Polymers (Basel) 2020;12(8):1786. DOI: 10.3390/polym12081786.
  6. Boaro LCC, Lopes DP, de Souza A, et al. Clinical performance and chemical-physical properties of bulk-fill composites resin: A systematic review and meta-analysis. Dent Mater 2019;35(10): e249–e264. DOI: 10.1016/
  7. Behery H, El-Mowafy O, El-Badrawy W, et al. Gingival microleakage of class II bulk-fill composite resin restorations. Dent Med Probl 2018;55(4):383–388. DOI: 10.17219/dmp/99264.
  8. Tardem C, Albuquerque E, Lopes L, et al. Clinical time and postoperative sensitivity after use of bulk-fill (syringe and capsule) vs. incremental filling composites: A randomized clinical trial. Braz Oral Res 2019;33(0):e089. DOI: 10.1590/1807-3107bor-2019.vol33.0089.
  9. Schroeder M, Reis A, Luque–Martinez I, et al. Effect of enamel bevel on retention of cervical composite resin restorations: A systematic review and meta-analysis. J Dent 2015;43(7):777–788. DOI: 10.1016/j.jdent.2015.02.017.
  10. Soliman S, Preidl R, Karl S, et al. Influence of cavity margin design and restorative material on marginal quality and seal of extended class II resin composite restorations in vitro. J Adhes Dent 2016;18(1):7–16. DOI: 10.3290/j.jad.a35520.
  11. Apel Z, Vafaeian B, Apel D, et al. Occlusal stresses in beveled versus non-beveled tooth preparation. Biomed Eng Adv 2021;12(2):1–5. DOI: 10.1016/j.bea.2021.100010.
  12. Meurer J, Rizzante F, Maenossono R, et al. Effect of cavosurface angle beveling on the exposure angle of enamel prisms in different cavity sizes. Microsc Res Tech 2020;83(3):304–309. DOI: 10.1002/jemt.23415.
  13. Coelho-De-Souzal F, Camargoll J, Beskowll T, et al. A randomized double-blind clinical trial of posterior composite restorations with or without bevel: 1-Year follow-up. J Appl Oral Sci 2012;20(2):174–179. DOI: 10.1590/s1678-77572012000200009
  14. Nordbo H, Leirskar J, von der Fehr F. Saucer-shaped cavity preparations for posterior approximal resin composite restorations: Observations up to 10 years. Quintessence Int 1998;29(1):5–11.
  15. Carrera CA, Li Y, Chen R, et al. Interfacial degradation of adhesive composite restorations mediated by oral biofilms and mechanical challenge in an extracted tooth model of secondary caries. J Dent 2017;66:62–70. DOI: 10.1016/j.jdent.2017.08.009.
  16. Correia A, Pereira V, Bresciani E, et al. Influence of cavosurface angle on the stress concentration and gaps formation in class V resin composite restorations. J Mech Behav Biomed Mater 2019;97:272–277. DOI: 10.1016/j.jmbbm.2019.05.034.
  17. Anand VS, Kavitha C, Subbarao CV. Effect of cavity design on the strength of direct posterior composite restorations: An empirical and FEM analysis. Int J Dent 2011:2011:214751. DOI: 10.1155/2011/214751.
  18. Ritter AV, Boushell LW, Walter K. Sturdevants Art and Science of Operative Dentistry, 7th edition. Mosby; 2018.
  19. Clark D. Simple and esthetic. Inside Dentistry 2017;13(11):27–29. Available from:
  20. Abdulmajeed AA, Donovan TE, Cook R, et al. Effect of preheating and fatiguing on mechanical properties of bulk-fill and conventional composite resin. Oper Dent 2020;45(4):387–395. DOI: 10.2341/19-092-L.
  21. Jacker–Guhr S, Ibarra G, Oppermann L, et al. Evaluation of microleakage in class V composite restorations using dye penetration and micro-CT. Clin Oral Investig 2016;20(7):1709–1718. DOI: 10.1007/s00784-015-1676-0.
  22. Raskin A, D'Hoore W, Gonthier S, et al. Reliability of in vitro microleakage tests: A literature review. J Adhes Dent 2001;3(4): 295–308. PMID: 11893045.
  23. Daghrery A, Yaman P, Lynch M, et al. Evaluation of micro-CT in the assessment of microleakage under bulk-fill composite restorations. Amer J Dent 2022;35(2):128–132. PMID: 35798706.
  24. Neves A, Jaecques S, Van Ende A, et al. 3D-microleakage assessment of adhesive interfaces: Exploratory findings by muCT. Dent Mater 2014:30(8):799–807. DOI: 10.1016/
  25. Sun J, Eidelman N, Lin–Gibson S. 3D mapping of polymerization shrinkage using X-ray micro-computed tomography to predict microleakage. Dent Mater 2009;25(3):314–320. DOI: 10.1016/
  26. Zhao X, Li S, Gu L, et al. Detection of marginal leakage of Class V restorations in vitro by micro-computed tomography. Oper Dent 2014;39(2):174–180. DOI: 10.2341/12-182-L.
  27. Carrera CA, Lan C, Escobar–Sanabria D, et al. The use of micro-CT with image segmentation to quantify leakage in dental restorations. Dent Mater 2015;31(4):382–390. DOI: 10.1016/
  28. Raskin A, Tassery H, D'Hoore W, et al. Influence of the number of sections on reliability of in vitro microleakage evaluations. Amer J Dent 2003;16(3):207–210. PMID: 12967077.
  29. Rizzante F, Sedky R, Furuse A, et al. Validation of a method of quantifying 3D leakage in dental restorations. J Prosthet Dent 2020;123(6):839–844. DOI: 10.1016/j.prosdent.2019.05.019.
  30. Waltimo A, Könönen M. A novel bite force recorder and maximal isometric bite force values in healthy young adults. Scand J Dent Res 1991;101(3):171–175. DOI: 10.1111/j.1600-0722.1993.tb01658.x.
  31. Kuijs R, Fennis W, Kreulen C, et al. Fracture strength of cusp replacing resin composite restorations. Amer J Dent 2003;16(1):13–16. PMID: 12744406.
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