Table 1. Characteristics of the identified RCTs (n = 413).

	Sample size adequately reported		Sample size inadequately reported		Total		p-value
Journal	No.	%	No.	%	No.	%
AJODO	45	15	16	13	61	15	<0.001*
BJOMS	37	13	1	1	38	9
IJP	26	9	6	5	32	8
JCP	63	22	64	53	127	31
JE	55	19	14	12	69	17
PD	16	5	0	0	16	4
JADA	25	9	5	4	30	7
JDR	25	9	15	12	40	10
Continent
Europe	134	46	67	55	201	49	0.16*
Americas	111	38	35	29	146	35
Asia/other	47	16	19	16	66	16
No. authors
1–4	127	43	29	24	156	38	<0.001*
5–7	131	45	66	55	197	48
>7	34	12	26	21	60	15
Trial design
Cluster	1	0	4	3	5	1	0.02*
Crossover	37	13	12	10	49	12
Factorial	0	0	1	1	1	0
Non-inferiority	3	1	5	4	8	2
Parallel	208	71	86	71	294	71
Splitmouth	43	15	13	11	56	14
Methodologist involvement
No	245	84	83	69	328	79	<0.001*
Yes	47	16	38	31	85	21
Center
Single Center	251	86	90	74	341	83	<0.01*
Multi Center	41	14	31	26	72	17
Significance
No	140	48	53	44	193	47	0.44*
Yes	152	52	68	56	220	53
No. arms
2	238	82	103	85	341	83	0.21*
3	42	14	10	8	52	13
4	8	3	6	5	14	3
5	2	1	1	1	3	1
6	2	1	0	0	2	0
8	0	0	1	1	1	0
Total	292	100	121	100	413	100

*Pearson chi².