A systematic review on the accuracy of manufacturing techniques for cobalt chromium fixed dental prostheses

Figures & data

Figure 1. Search strategy.

Table 1. The included studies and the results they present regarding impression technique, tooth area, manufacturing technique, pre-set cement spacer, number of test specimens and reported gaps (in micrometer).

	Settings					Marginal gap			Internal gap			Total gap
Author	Impression	Tooth	Man Tech^a	Pre-set spacer	N	Fit	SD^b	Acc^c	Fit	SD	Acc	Fit	SD	Acc
Single crowns
Ates et al. [36]	Conv^d	PM^f	CLW^j	0 (0.5)–30	10	25	4	25
	Conv	PM	HM^k	0 (0.5)–30	10	52	11	52
	Conv	PM	AM^l	0 (0.5)–30	10	28	6	28
Dahl et al. [37]	Conv	INC^g	LW^m	0–20	3				64	30	44	58	23	38
	Dig^e	INC	HM	50–90	3				162	153	72	90	78	0
	Dig	INC	AM	55–80	3				106	53	26	82	37	2
Gunsoy et al. [38]	Conv	PM	LW	50	16	86	20	86	107	27	57	97		47
	Dig	PM	CLW	0 (0.5)–50	16	85	19	85	93	21	43	92		42
	Dig	PM	HM	0 (0.5)–50	16	84	18	84	90	20	40	89		39
	Dig	PM	AM	0 (0.5)–50	16	52	11	52	82	17	32	66		16
	Conv	M^h	LW	50	16	96	19	96	149	23	99	121		71
	Dig	M	CLW	0 (0.5)–50	16	90	17	90	118	21	68	104		54
	Dig	M	HM	0 (0.5)–50	16	88	16	88	117	21	67	103		53
	Dig	M	AM	0 (0.5)–50	16	40	10	40	83	10	32	58		8
Harish et al. [39]	Conv	PM	CLW	20	10	177	26	157	187	11	167
	Conv	PM	AM	20	10	102	17	82	108	11	88
Huang et al. [40]	Conv	M	LW	70	110	91	36	21	196	87	126	161	70	91
	Conv	M	AM	70	110	76	33	6	219	76	149	170	81	101
Kim et al. [41]	Conv	M	CLW	30	10	124	52	94	170	56	140	159	55	129
Kim et al. [42]	Conv	M	LW	0 (0.5)–30	10							64	14	34
	Conv	M	SMill^n	0 (0.5)–30	10							33	5	3
	Conv	M	AM	0 (0.5)–30	10							47	9	17
Kocaagaoglu et al. [43]	Conv	M	CLW	0 (0.5)–30	10	102	26	102	131	23	101	121	24	91
	Conv	M	SMill	0 (0.5)–30	10	72	28	72	159	23	129	130	24	100
	Conv	M	Mill	0 (0.5)–30	10	68	12	68	143	26	113	118	21	88
	Conv	M	AM	0 (0.5)–30	10	73	15	73	149	27	119	124	23	94
Lovgren et al. [44]	Conv	M	CLW	0 (0.5)–50	10	104	33	104	134	24	84	127	27	77
	Conv	M	HM	0 (0.5)–50	10	91	24	91	126	22	76	117	22	67
	Conv	M	AM	0 (0.5)–50	10	53	19	53	111	19	61	96	19	46
Park et al. [45]	Conv	CA^i	LW	0 (1)–25	10	34	8	34	69	21	44	53	33	28
	Conv	CA	SMill	0 (1)–25	10	62	16	62	109	22	84	88	39	63
	Conv	CA	HM	0 (1)–25	10	37	8	37	75	9	50	56	31	31
Park et al. [46]	Conv	CA	LW	0 (1)–25	10	40	10	40	77	10	52	58	31	33
	Conv	CA	HM	0 (1)–25	10	63	18	63	110	23	85	89	39	64
	Conv	CA	AM	0 (1)–25	10	71	19	71	128	23	103	103	43	78
Sundar et al. [13]	Conv	PM	AM	0 (0.5)–30	10	56	11	56
FDPs
Keul et al. [47]	Conv	4-unit	HM	30 (0.5)–60	12	91	91	61	143	75	83	130	79	70
	Dig	4-unit	HM	30 (0.5)–60	12	57	27	27	116	45	56	101	41	41
Kim et al. [48]	Conv	3-unit	AM	0 (0.5)–30	10	113	50	113
Nesse et al. [49]	Conv	3-unit	LW	20	10				116		96
	Conv	3-unit	HM	0 (0.5)–50	10				95		45
	Conv	3-unit	AM	0 (0.5)–50	10				156		106
Svanborg et al. [50]	Conv	3-unit	HM	30 (0.5)–60	10							117	12	54
	Dig	3-unit	HM	30 (0.5)–60	10							93	8	33
Ueda et al. [51]	Conv	4-unit	HM	30 (1.5)–60	12	81	66	53	98	62	38	94	63	34
	Dig	4-unit	HM	30 (1.5)–60	12	32	35	2	60	30	0	53	31	7
Örtorp et al. [52]	Conv	3-unit	LW	0 (0.5)–50	8	81	40	81				133	86	83
	Conv	3-unit	CLW	0 (0.5)–50	8	112	46	112				118	79	68
	Conv	3-unit	HM	0 (0.5)–50	8	152	91	152				166	136	116
	Conv	3-unit	AM	0 (0.5)–50	8	49	35	49				84	58	34

^aManufacturing technique; ^bStandard deviation; ^cAccuracy; ^dConventional; ^eDigital; ^fPremolar; ^gIncisor; ^hMolar; ⁱCanine; ^jCAD/lost-wax; ^kHard milling; ^lAdditive manufacturing; ^mLost wax; ⁿSoft milling.

Table 2. The different machines, CAD/CAM-systems and alloys presented in the included studies.

Casting machine	CAD system	CAM system	Alloy
Mikrotek N/S^a [36]	3Shape D700 [38,42,44,48]	Yenadent N/S [36]	BEGO Wirobond 280 [37,44]
BEGO Fornax [39,45,46]	3Shape D800 [45,46]	Yenadent DC40 [43]	BEGO Wirobond C [40,48,49,52]
BEGO Nautilus CC [44,52]	3Shape D640 [52]	Concept laser M1 [36,38,42,44]	BEGO N/S [36]
Renfert N/S [40]	3Shape N/S [37]	Eosint M270 [13,39,43,46,48]	EOS MP1 [39]
N/S [37,38,41,48,49]	3M Lava [51]	BEGO N/S [40]	EOS SP2 [13,42,43,46,48]
	Straumann Cares [47,50]	Straumann milling [47,50]	Straumann Coron [47,50]
	Dental Wings 3-series [36,43]	Ceramill Motion2 [43,45,48]	Degudent StarloyC [41,45,46]
	BEGO N/S [40]	Roeders RXD5 [44]	Ceramill Sintron [43,45,48]
	Identica Blue/ Exocad [41]	Datron D5 [45,46]	Gialloy CB [44]
	Ceramill Mind [48]	3M Lava CNC 500 [51]	Remanium Star CL [44]
	Ceramill Match2 [43]	Wieland Zeno 4820 [52]	Kulzer Cara milled [49]
	EOS/ Cambridge [43]	Biomain N/S [52]	Kulzer Cara SLM [49]
		Dentware N/S [37]	ACF LunaNEM [52]
		3D Systems Projet1200 [41]	Whitepeaks Coprabond K [36]
			Dentaurum N/S [36]
			Eisenbacher ED Kera-Disc [37,43,45,46]
			Eisenbacher ED Kera-C [43]
			Dentware CoCr [37]
			N/S [51,52]

^a N/S: Not specified.

Figure 2. Fit and accuracy (μm) of single crowns (SC), multi-unit fixed dental prostheses (FDP) and combined divided by marginal gap, internal gap and total gap.

Figure 3. Marginal gap fit and accuracy (μm) of single crowns (SC), multi-unit fixed dental prostheses (FDP) and combined divided by production technique. SM: Soft milling, AM: Additive manufacturing, HM: Hard milling, LW: Lost wax, CLW: CAD lost wax.

Figure 4. Internal gap fit and accuracy (μm) of single crowns (SC), multi-unit fixed dental prostheses (FDP) and combined divided by production technique. SM: Soft milling, AM: Additive manufacturing, HM: Hard milling, LW: Lost wax, CLW: CAD lost wax.

Figure 5. Total gap fit and accuracy (μm) of single crowns (SC), multi-unit fixed dental prostheses (FDP) and combined divided by production technique. SM: Soft milling, AM: Additive manufacturing, HM: Hard milling, LW: Lost wax, CLW: CAD lost wax.

Figure 6. Fit and accuracy (μm) of conventional and digital impressions divided by marginal gap, internal gap and total gap.

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