A retrospective multicenter study comparing metal–ceramic and composite single crowns performed in public general dentistry: 5-year results

Figures & data

Table 1. Sample characteristics, including gender and age, tooth position and endodontic status by group of crown type (metal–ceramic or composite).

	Metal–ceramic crowns			Composite crowns
	Age			Age
	n	Mean	SD	n	Mean	SD
Gender and age
Men	141	57.4	10.5	139	58.6	12.6
Women	159	56.7	12.2	161	57.5	12.5
All	300	57.0	11.4	300	58.0	12.5
Tooth position	n	%		n	%
Molar maxilla	52	17		67	22
Molar mandible	123	41		112	37
Premolar maxilla	82	27		77	26
Premolar mandible	43	14		44	15
Endodontic status^a	n	valid %		n	valid %
No root canal treatment	173	58		142	48
Root canal treatment and post-and-core	102	34		76	26
Root canal treatment without post-and-core	23	8		79	27

^aFive teeth (two MC and three composite) lacked information on endodontic status.

Table 2. Survival rate at 5-year follow-up by group of crown type (metal–ceramic and composite) and background variables.

	Survival
	Metal–ceramic crowns		Composite crowns
	n	%	n	%
Gender
Men	133	94	90	65
Women	146	92	121	75
All	279	93	211	70
Tooth position
Molar maxilla	50	96	45	67
Molar mandible	116	94	82	73
Premolar maxilla	73	89	54	70
Premolar mandible	40	93	30	68
Endodontic status
No root canal treatment	165	94	105	73
Root canal treatment and post-and-core	93	93	51	68
Root canal treatment without post-and-core	19	83	55	70

Table 3. Logistic regressions in total (model 1) and separated by type of crown (model 2 and 3) with survival as dependent variable and potential discriminatory variables as independents.

	Model 1, Total (survival: yes = 488/no = 107)			Model 2, Composite crowns (survival: yes = 211/no = 86)			Model 3, Metal–ceramic crowns (survival: yes = 277/no = 21)
Independents	OR	95% CI	p	OR	95% CI	p	OR	95% CI	p
Type of crown
Composite 0/MC 1	5.2	3.1–8.8	<0.001
Gender
Men 0/Women 1	1.4	0.9–2.2	0.132	1.7	1.0–2.9	0.039	0.7	0.3–1.7	0.401
Tooth position^a
Premolar 0/Molar 1	1.3	0.8–2.1	0.251	1.1	0.7–2.0	0.628	1.9	0.7–4.8	0.193
Endodontic status
No RCT			0.499			0.814			0.169
RCT with post 1	0.9	0.5–1.5		0.9	0.5–1.6		1.0	0.4–2.8
RCT without post 2	0.7	0.4–1.3		0.8	0.4–1.6		0.3	0.1–1.1

Significant p values in italic.

Nagelkerke r² = 0.147 (model 1), 0.024 (model 2) and 0.048 (model 3).

^aTooth position categorized into premolar or molar irrespective of jaw.

Table 4. Number of complications for each crown and number and % of surviving and lost composite and MC crowns with complications during the 5-year follow-up.

		Number of complications				Total number of crowns with complications
Type of crown	Status at follow-up	0	1	2	≥3	n	%
Composite n = 300	Surviving	154	49	8	0	57	27
	Lost	0	77	10	2	89	100
MC crowns n = 300	Surviving	273	3	3	0	6	2
	Lost	0	20	1	0	21	100