Tabla 2. Comparación entre los dos instrumentos y las variables edema, dolor y trismus, según la edad y sexo.

Variables		Pieza de mano recta rotatorio			p-valor	Piezoeléctrico			p-valor
		Leve	Moderada	Grave		Leve	Moderada	Grave
Edema 3 días
Edad	18 a 21 años	4 (25%)	5 (31.3%)	7 (43.8%)	0.740	8 (57.1%)	4 (28.6%)	2 (14.3%)	0.460
	22 a 25 años	1 (25%)	2 (59.0%)	1 (25%)		5 (83.3%)	1 (16.7%)	0 (0%)
Edema 5 días
Edad	18 a 21 años	9 (56.3%)	4 (25%)	3 (18.8%)	0.160	11 (78.6%)	2 (14.3%)	1 (7.1%)	0.790
	22 a 25 años	1 (25%)	3 (75%)	0 (0%)		5 (83.3%)	1 (16.7%)	0 (0%)
Edema 8 días
Edad	18 a 21 años	12 (75%)	4 (25%)	0 (0%)	1.000	12 (85.7%)	2 (14.3%)	0 (0%)	0.320
	22 a 25 años	3 (75%)	1 (25%)	0 (0%)		6 (100%)	0 (0%)	0 (0%)
Dolor 3 días
Edad	18 a 21 años	9 (56.3%)	6 (37.5%)	1 (6.3%)	0.060	10 (71.4%)	4 (28.6%)	0 (0%)	0.270
	22 a 25 años	2 (50%)	0 (0%)	2 (50%)		4 (66.7%)	1 (16.7%)	1 (16.7%)
Dolor 5 días
Edad	18 a 21 años	13 (81.3%)	2 (12.5%)	1 (6.3%)	0.030	13 (92.9%)	0 (0%)	1 (7.1%)	0.240
	22 a 25 años	1 (25%)	3 (75%)	0 (0%)		5 (83.3%)	1 (16.7%)	0 (0%)
Dolor 8 días
Edad	18 a 21 años	16 (100%)	0 (0%)	0 (0%)	<0.001	14 (100%)	0 (0%)	0 (0%)	0.110
	22 a 25 años	2 (50%)	2 (50%)	0 (0%)		5 (83.3%)	1 (16.7%)	0 (0%)
Edema 3 días
Sexo	Masculino	4 (44.4%)	2 (22.2%)	3 (33.3%)	0.180	6 (60%)	4 (40%)	0 (0%)	0.140
	Femenino	1 (9.1%)	5 (45.5%)	5 (45.5%)		7 (70%)	1 (10%)	2 (20%)
Edema 5 días
Sexo	Masculino	5 (55.6%)	2 (22.2%)	2 (22.2%)	0.480	8 (80%)	2 (20%)	0 (0%)	0.510
	Femenino	5 (45.5%)	5 (45.5%)	1 (9.1%)		8 (80%)	1 (10%)	1 (10%)
Edema 8 días
Sexo	Masculino	6 (66.7%)	3 (33.3%)	0 (0%)	0.430	10 (100%)	0 (0%)	0 (0%)	0.130
	Femenino	9 (81.8%)	2 (18.2%)	0 (0%)		8 (80%)	2 (20%)	0 (0%)
Trismus 3 días
Sexo	Masculino	6 (66.7%)	3 (33.3%)	0 (0%)	0.490	9 (90%)	1 (10%)	0 (0%)	0.120
	Femenino	5 (45.5%)	5 (45.5%)	1 (9.1%)		6 (60%)	4 (40%)	0 (0%)
Trismus 5 días
Sexo	Masculino	7 (77.8%)	2 (22.2%)	0 (0%)	0.290	10 (100%)	0 (0%)	0 (0%)	0.020
	Femenino	5 (45.5%)	5 (45.5%)	1 (9.1%)		6 (60%)	4 (40%)	0 (0%)
Trismus 8 días
Sexo	Masculino	7 (77.8%)	2 (22.2%)	0 (0%)	0.450	10 (100%)	0 (0%)	0 (0%)	0.130
	Femenino	6 (54,5%)	4 (36,4%)	1 (9,1%)		8 (80%)	2 (20%)	0 (0%)

Prueba Chi cuadrado (p < 0,05)