The Effect of Student Experience and Tooth Location on Finish Line Width and Angle of Full Metal Crown Preparations in Preclinical Setting

Figures & data

Figure 1 Sample of the scanned prepared tooth.

Figure 2 Sample of the finish line angle measurement in the software.

Figure 3 Sample of the finish line width measurement in the software.

Table 1 Statistical Analysis of Finish Line Width at Different Tooth Locations by Semester

Tooth	Location	First Semester Finish Line Width Mean (SD)	Second Semester Finish Line Width Mean (SD)	P-value	95% Confidence Interval for Difference
					Lower Bound	Upper Bound
Mandibular First Molar	B	0.56 (0.09)	0.53 (0.15)	0.515	−0.067	0.133
	DB	0.61 (0.14)	0.65 (0.16)	0.564	−0.156	0.085
	D	0.53 (0.13)	0.71 (0.20)	0.010*	−0.327	−0.046
	DL	0.57 (0.16)	0.72 (0.21)	0.028*	−0.285	−0.017
	L	0.54 (0.13)	0.57 (0.16)	0.568	−0.133	0.073
	ML	0.61 (0.16)	0.65 (0.21)	0.606	−0.175	0.103
	M	0.51 (0.14)	0.57 (0.12)	0.417	−0.197	0.082
	MB	0.58 (0.17)	0.73 (0.16)	0.005*	−0.260	−0.047
	All locations	0.56 (0.14)	0.64 (0.17)
Mandibular Second Molar	B	0.63 (0.19)	0.57 (0.19)	0.221	−0.038	0.163
	DB	0.74 (0.19)	0.71 (0.25)	0.590	−0.088	0.153
	D	0.70 (0.25)	0.76 (0.28)	0.366	−0.204	0.076
	DL	0.79 (0.27)	0.76 (0.21)	0.702	−0.108	0.160
	L	0.68 (0.23)	0.60 (0.12)	0.130	−0.024	0.182
	ML	0.70 (0.22)	0.65 (0.28)	0.480	−0.089	0.188
	M	0.64 (0.29)	0.76 (0.28)	0.096	−0.258	0.021
	MB	0.68 (0.18)	0.67 (0.16)	0.910	−0.100	0.112
	All locations	0.70 (0.23)	0.69 (0.22)

Note: *Statistically significant at P <0.05.

Abbreviations: SD, standard deviation; B, buccal; DB, distobuccal; D, distal; DL, distolingual; L, lingual; ML, mesiolingual; M, mesial; MB, mesiobuccal.

Table 2 Statistical Analysis of Finish Line Width at Different Locations by Tooth Position

Tooth Location	Mandibular First Molar Finish Line Width Mean (SD)	Mandibular Second Molar Finish Line Width Mean (SD)	P-value	95% Confidence Interval for Difference
				Lower Bound	Upper Bound
B	0.54 (0.12)	0.60 (0.19)	0.102	−0.130	0.012
DB	0.63 (0.15)	0.73 (0.22)	0.028*	−0.181	−0.011
D	0.61 (0.19)	0.73 (0.26)	0.033*	−0.207	−0.009
DL	0.64 (0.20)	0.77 (0.23)	0.007*	−0.226	−0.036
L	0.55 (0.14)	0.64 (0.18)	0.019*	−0.160	−0.015
ML	0.63 (0.18)	0.68 (0.25)	0.308	−0.148	0.047
M	0.54 (0.14)	0.70 (0.29)	0.002*	−0.257	−0.060
MB	0.66 (0.18)	0.68 (0.19)	0.621.	−0.094	0.056
All locations	0.6 (0.16)	0.69 (0.23)

Note: *Statistically significant at P <0.05.

Abbreviations: SD, standard deviation; B, buccal; DB, distobuccal; D, distal; DL, distolingual; L, lingual; ML, mesiolingual; M, mesial; MB, mesiobuccal.

Table 3 Statistical Analysis of Finish Line Angle at Different Tooth Locations by Semester

Tooth	Location	First Semester Finish Line Angle Mean (SD)	Second Semester Finish Line Angle Mean (SD)	P-value	95% Confidence Interval for Difference
					Lower Bound	Upper Bound
Mandibular First Molar	B	156.42 (14.88)	152.85 (14.52)	0.471	−6.249	13.386
	DB	155.74 (12.70)	155.49 (14.39)	0.957	−8.942	9.437
	D	154.84 (12.16)	141.26 (15.39)	0.005*	4.230	22.931
	DL	154.78 (15.24)	152.95 (11.56)	0.715	−8.153	11.824
	L	153.26 (14.85)	156.19 (12.70)	0.508	−11.700	5.844
	ML	151.14 (12.87)	149.70 (17.59)	0.768	−8.264	11.146
	M	150.82 (14.73)	148.14 (16.22)	0.604	−7.577	12.951
	MB	152.82 (14.69)	155.00 (16.86)	0.659	−11.966	7.608
	All locations	153.73 (14.02)	151.45 (14.90)
Mandibular Second Molar	B	150.56 (14.72)	151.46 (17.98)	0.856	−10.716	8.918
	DB	145.61 (12.85)	145.52 (17.83)	0.984	−9.095	9.284
	D	144.77 (15.56)	145.52 (15.87)	0.872	−10.110	8.592
	DL	148.41 (15.48)	148.91 (20.02)	0.922	−10.480	9.497
	L	152.13 (11.45)	154.03 (16.21)	0.667	−10.677	6.867
	ML	151.64 (13.19)	146.52 (17.34)	0.296	−4.578	14.831
	M	155.47 (18.43)	151.14 (15.57)	0.403	−5.932	14.596
	MB	154.31 (13.12)	151.09 (17.13)	0.514	−6.565	13.009
	All locations	150.36 (14.35)	149.27 (17.24)

Note: *Statistically significant at P <0.05.

Abbreviations: SD, standard deviation; B, buccal; DB, distobuccal; D, distal; DL, distolingual; L, lingual; ML, mesiolingual; M, mesial; MB, mesiobuccal.

Table 4 Statistical Analysis of Finish Line Angle at Different Locations by Tooth Position

Tooth Location	Mandibular First Molar Finish Line Angle Mean (SD)	Mandibular Second Molar Finish Line Angle Mean (SD)	P-value	95% Confidence Interval for Difference
				Lower Bound	Upper Bound
B	154.63 (14.62)	151.01 (16.22)	0.302	−3.317	10.567
DB	155.61 (13.40)	145.56 (15.34)	0.003*	3.551	16.547
D	148.05 (15.32)	145.14 (15.57)	0.384	−3.705	9.519
DL	153.86 (13.38)	148.66 (17.66)	0.146	−1.859	12.267
L	154.72 (13.72)	153.08 (13.89)	0.599	−4.557	7.848
ML	150.42 (15.23)	149.08 (15.43)	0.699	−5.524	8.201
M	149.48 (15.35)	153.31 (16.98)	0.297	−11.084	3.432
MB	153.91 (15.65)	152.70 (15.15)	0.727	−5.705	8.136

Note: *Statistically significant at P <0.05.

Abbreviations: SD, standard deviation; B, buccal; DB, distobuccal; D, distal; DL, distolingual; L, lingual; ML, mesiolingual; M, mesial; MB, mesiobuccal.