Type to search

Dental Specialties Research Restorative Dentistry Supporting Your Practice

Effect of composite type and placement technique on cuspal strain

Dear colleagues,

I thought you might enjoy reading this recently-published free access article of great pertinence to everyday general practice dentistry.

Effect of composite type and placement technique on cuspal strain

Vilhelm G. Ólafsson DDS, MS  André V. Ritter DDS, MS, MBA  Edward J. Swift DMD, MS Jr. Lee W. Boushell DMD, MS  Ching‐Chang Ko DDS, MS, PhD  Gabrielle R. Jackson DDS Sumitha N. Ahmed BDS, MS  Terence E. Donovan DDS

Link to free access full text of this article in the Journal of Esthetic and Restorative Dentistry is here:




To compare the cuspal strain in Class II restorations made with bulk‐fill and conventional composite resins.

Materials and methods

Fifty extracted maxillary premolars were mounted into phenolic rings and divided into five groups (n = 10). Specimens received standardized MOD preparations. A two‐step self‐etch adhesive was applied and the preparations were restored using a custom matrix as follows: Filtek Supreme Ultra in eight 2‐mm increments (FSUI); Filtek Supreme Ultra in bulk (FSUB); SonicFill in bulk (SF); SureFil SDR flow in bulk, covered with a 2‐mm occlusal layer of Filtek Supreme Ultra (SDR/FSU); Tetric EvoCeram Bulk Fill in bulk (TEBF). Strain gages bonded to the buccal and lingual cusps recorded cuspal strain during restorations. End strain values were determined and data were subjected to Kruskal‐Wallis testing, followed by one‐way ANOVA and Tukey´s post hoc test.


Combined strain values and standard deviations (in µɛ) were: FSUI: 723 ± 102.8, FSUB: 929.2 ± 571.9, SF: 519.1 ± 80.2, SDR‐FSU: 497.4 ± 67.6 and TEBF: 604.5 ± 127.1. A significant difference was found between group FSUI and groups SF, SDR‐FSU, and TEBF. Group FSUB showed significantly higher mean strain and greater standard deviation than all other groups due to cuspal fractures, and was thus excluded from the statistical analysis.


The tested bulk‐fill composite resins exerted less strain onto tooth structure than the incrementally placed conventional composite resin, although the magnitude of generated strain was product‐dependent. Bulk‐filling with conventional composite resins is contraindicated.

Clinical significance

Bulk‐fill composite resins exerted less strain onto adjacent tooth structure than a traditional composite, even when that composite was placed incrementally. Bulk‐filling with traditional composite resins is unpredictable and contraindicated.


Given that we are on the topic of posterior composites, I thought you also might be interested in these observations of a panel of GP dentists (convened by the American Dental Association) about their usage of posterior composite materials today: ACE Panel Report Posterior Composite Restorations. To learn more about the ADA Clinical Evaluators (ACE) Panel and its work, please click here.

What is your preferred type of posterior composite material (incremental or bulk-fill)? Do you favour one particular brand over others? Please share your insights with us through the “Leave a Reply” box below. Many thanks.




  1. Dr. CLIFFORD LEACHMAN July 13, 2018

    Empress Direct from Ivoclar
    I have never bulk filled, its simply a commercial sales gimmick to sell bulk fill composite, unless its autopolymerizing.
    Truckloads of data showing the polymerization to be soooo poor when the layer is thicker and distant from the light.
    But should we really be surprised?

  2. brady eason July 15, 2018

    warmed Tetric EvoCeram Bulk Fill


Leave a Comment

Your email address will not be published. Required fields are marked *