Wear and Surface Structure of Various Core Materials and Composites

Objectives: Sometimes crown preparation is not performed immediately after tooth reconstruction using core build-up materials, therefore wear might occure. This investigation evaluated wear, surface roughness and structure of 10 core build-up composites (CBC), 2 glassionomer cements (GIC) and 4 posterior restorative composites (PRC). Methods: 16 materials (n=9) were investigated: CBC= Build-It (BI, JenericPentron), ChromaCore (CC, Morita), CorePaste (CP, DentMat), LuxaCore (LCN) and LuxaCore SmartMix (LCS; DMG), MulticoreFlow (MF; IvoclarVivadent), Rebilda D, LC and DC (RD, RLC, RDC; Voco), Ti-Core (TC; EDS); GIC= Ketac Fil (KF), Ketac Molar (KM; 3MEspe); PRC= Ecusit (EC; DMG), Grandio (GR; Voco), Quixfil (QU; DentsplyDeTrey), TetricEvoCeram (TE; Ivoclar Vivadent). Three-body wear (Willytec, 200.000cycles in millet seed) was tested after water storage (14d,20°C). Wear and surface roughness RA (DIN 4768) were measured using a profilometer. Surface structures were evaluated using SEM. Results were statistically analysed (Mann-Whitnex U-test, a=0.05). Results: Wear and RA values are presented in the table. Wear of PRC was significantly lower than that of all core materials (p<0.05) except for RLC-EC and RLC-TE. Wear of TC was significantly higher than all other materials (p<0.05). RA of CBC except for CP and TC were significantly lower than GIC and PRC except for EC. BI, MF, RLC, EC and TE demonstrated homogenous surface structures. Conclusion: Wear of CBC differed widely and was higher than that of PRC for most materials, whereas their roughnesses were relatively low and their surfaces smoother except for CP and TC.

	CBC
code	BI	CC	CP	LCN	LCS	MF	RD	RLC	RDC	TC
wear (µm)	49	48	64	65	76	59	63	43	52	90
RA (µm)	0.7	0.6	1.5	0.9	0.8	0.8	0.9	0.6	0.8	1.3
	GIC			PRC
code	KF	KM	EC	GR	QU	TE
wear (µm)	63	71	42	18	46	40
RA (µm)	2.5	1.3	0.7	1.2	1.0	1.3