Bond strength of conventional, subtractive, and additive manufactured denture bases to soft and hard relining materials.

Affiliation

Wemken G(1), Burkhardt F(1), Spies BC(2), Kleinvogel L(1), Adali U(3), Sterzenbach G(3), Beuer F(3), Wesemann C(4).
Author information:
(1)Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
(2)Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany. Electronic address: [Email]
(3)Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Assmanshauser Str. 4-6, 14197 Berlin, Germany.
(4)Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Assmanshauser Str. 4-6, 14197 Berlin, Germany.

Abstract

OBJECTIVE: To investigate the tensile and flexural strength of poured, subtractive, and additive manufactured denture base methacrylates bonded to soft and hard relining materials after hydrothermal cycling and microwave irradiation. METHODS: This study included a conventional (CB), subtractive (SB), and additive (AB) base material as well as a soft (SCR) and hard (HCR) chairside and one hard laboratory-side (HLR) relining material. Reference bodies of the base materials and bonded specimens to the relining materials were produced with a rectangular cross-section. The specimens were either pre-treated by water storage (50 h, 37 °C), hydrothermal cycling (5000 cycles, 5 °C and 55 °C, 30 s each), or microwave irradiation (6 cycles, 640 W, 3 min, wet). A tensile and four-point bending test were performed for a total of 504 specimens. Data were analysed using multivariate analysis of variance (MANOVA) with post-hoc Tukey tests (α = 0.05). RESULTS: In comparison with the other reference groups SB showed marginally higher tensile and flexural strength (p < 0.047). Bond strength to SCR was affected neither by the base material nor by the pre-treatment (p > 0.085). HCR demonstrated twice the bond strength to AB compared with SB and CB (p ≤ 0.001). HLR showed the highest bond strength to CB (p ≤ 0.001). There was no difference between the specimens after hydrothermally cycling and microwave irradiation (p > 0.318). SIGNIFICANCE: The bond strength of hard relining materials to subtractive and additive manufactured denture bases differ compared with conventional pouring.