Surface roughness and oxygen inhibited layer control in bulk-fill and conventional nanohybrid resin composites with and without polishing: in vitro study

Table 4 Surface roughness variation between before and after polishing of bulk fill and conventional nanohybrid resin composites, with and without oxygen inhibited layer control

Resin composite	(\({\overline{\text{X}}}_{{\text{f}}} - {\overline{\text{X}}}_{{\text{i}}}\))	Median	SD	SE	95% CI		w	t	p*	K–W	p**
Resin composite		Median	SD	SE	LL	UL	w	t	p*	K–W	p**
TNC-BF(G)	− 0.489	− 0.419^a	0.243	0.077	− 0.663	− 0.315	0.060	− 6.353	0.000	22.462	0.021**
TNC-BF	− 0.362	− 0.254^a	0.465	0.147	− 0.695	− 0.030	0.196	− 2.463	0.036
TNC-CN (G)	− 0.296	− 0.272^a	0.145	0.046	− 0.400	− 0.192	0.334	− 6.436	0.000
TNC-CN	− 0.452	− 0.552^a	0.266	0.084	− 0.642	− 0.262	0.227	− 5.384	0.000
O-BF (G)	− 0.170	− 0.222^a	0.319	0.101	− 0.398	0.058	0.917	− 1.691	0.125
O-BF	− 0.518	− 0.504^a	0.441	0.140	− 0.833	− 0.202	0.338	− 3.709	0.005
O-CN (G)	− 0.389	− 0.412^a	0.248	0.079	− 0.567	− 0.212	0.493	− 4.959	0.001
O-CN	− 0.295	− 0.303^a	0.201	0.064	− 0.439	− 0.151	0.518	− 4.640	0.001
F-BF (G)	− 0.134	− 0.103^a	0.110	0.035	− 0.213	− 0.056	0.192	− 3.877	0.004
F-BF	− 0.169	− 0.188^a	0.086	0.027	− 0.231	− 0.107	0.387	− 6.187	0.000
F-CN (G)	− 0.420	− 0.430^a	0.244	0.077	− 0.594	− 0.246	0.333	− 5.448	0.000
F-CN	− 0.288	− 0.294^a	0.212	0.067	− 0.440	− 0.136	0.886	− 4.294	0.002

Equal letters (a) were used to indicate no significant difference (p > 0.05) for independent pairwise comparison, according to Bonferroni post hoc adjustment
(\({\overline{\text{X}}}_{{\text{f}}} - {\overline{\text{X}}}_{{\text{i}}}\)): Mean difference; (\({\overline{\text{X}}}_{{\text{f}}}\)): After polishing; (\({\overline{\text{X}}}_{{\text{i}}}\)): Before polishing; SD Standard deviation; SE Standard error of mean; 95% CI 95% confidence interval, LL Lower limit, UL Upper limit; w: Normality analysis based on Shapiro Wilk Test (normal distribution: p > 0.05); t: Student’s t-test for related measures (significant differences *p < 0.05). K–W Kruskall Wallis test (significant differences in at least two groups: **p < 0.05)

ISSN: 1472-6831