Relation between internal adaptation and degree of conversion of short-fiber reinforced resin composites applied in bulk or layered technique in deep MOD cavities

Viktória Néma; Sándor Kunsági-Máté; Zsuzsanna Őri; Tamás Kiss; Péter Szabó; József Szalma; Márk Fráter; Edina Lempel

doi:10.1016/j.dental.2024.02.013

Relation between internal adaptation and degree of conversion of short-fiber reinforced resin composites applied in bulk or layered technique in deep MOD cavities

Dent Mater. 2024 Apr;40(4):581-592. doi: 10.1016/j.dental.2024.02.013. Epub 2024 Feb 16.

Authors

Viktória Néma¹, Sándor Kunsági-Máté², Zsuzsanna Őri³, Tamás Kiss⁴, Péter Szabó⁵, József Szalma⁶, Márk Fráter¹, Edina Lempel⁷

Affiliations

¹ Department of Operative and Esthetic Dentistry, Faculty of Dentistry, University of Szeged, Tisza Lajos Blvd 64-66, 6720 Szeged, Hungary.
² Department of Organic and Pharmacological Chemistry, University of Pécs Medical School, Faculty of Pharmacy, Honvéd street 1, 7624 Pécs, Hungary; János Szentágothai Research Center, University of Pécs, Ifjúság Street 12, 7624 Pécs, Hungary.
³ Department of Nutritional Sciences and Dietetics, University of Pécs, Faculty of Health Sciences, Vörösmarty Street 4, 7621 Pécs, Hungary; Department of Physical Chemistry and Materials Science, University of Pécs, Faculty of Sciences, Ifjúság Street 6, 7624 Pécs, Hungary.
⁴ Department of Pharmacology and Pharmacotherapy, University of Pécs Medical School, Szigeti Street 12, 7624 Pécs, Hungary.
⁵ János Szentágothai Research Center, University of Pécs, Ifjúság Street 12, 7624 Pécs, Hungary.
⁶ Department of Oral and Maxillofacial Surgery, University of Pécs Medical School, Tüzér Street 1, 7623 Pécs, Hungary.
⁷ Department of Restorative Dentistry and Periodontology, University of Pécs Medical School, Tüzér Street 1, 7623 Pécs, Hungary. Electronic address: lempel.edina@pte.hu.

PMID: 38368136
DOI: 10.1016/j.dental.2024.02.013

Abstract

Objective: The purpose was to evaluate the degree of conversion (DC), internal adaptation (IA) and closed porosity (CP) of short-fiber reinforced resin composites (SFRC) associated with layered or bulk restorative procedures in deep MOD cavities.

Methods: Eighty third molars with standardized MOD cavities (5-mm-depth, 2.5-mm-width) were randomly divided into four groups and restored as follows: 1) bulk SFRC; 2) layered SFRC; 3) flowable bulk-fill resin-based composites (RBC); 4) layered conventional RBC. After one-month wet storage the samples were subjected to micro-computed tomography measurements and scanning electron microscopy to assess the IA and CP. Micro-Raman spectroscopy was used to determine the DC in different depths. Data were subjected to ANOVA and Tukey's post-hoc test, multivariate analysis and partial eta-squared statistics (p < 0.05). Pearson correlation coefficient was determined to assess the relationship among the parameters of interest.

Results: Gap/total interface volume ratio ranged between 0.22-0.47%. RBCs applied in bulk revealed significantly lower gap volume (p < 0.001) and CP (p < 0.05). Each group showed complete detachment on the pulpal and partial on the lateral walls, except for group3. While the highest DC% was achieved by the conventional RBC (87.2%), followed by the flowable bulk-fill (81.2%), SFRC provided the best bottom to top DC ratio (bulk: 96.4%, layered: 98.7%). The effect of factors studied (RBC type, filling technique) on IA and DC was significant (p < 0.001).

Significance: Bulk placement of RBCs exhibited lower interfacial gap volume and achieved satisfactory DC without significant correlation between these parameters. Incremental insertion of SFRC had no advantage over bulk placement in terms of IA and DC.

Keywords: Bulk-fill; Degree of conversion; Internal adaptation; Porosity; Resin composite; Short fiber.

MeSH terms

Composite Resins* / chemistry
Dental Materials* / chemistry
Materials Testing
Polymerization
Surface Properties
X-Ray Microtomography

Substances

Dental Materials
Composite Resins