Shade-selection Consistency by Dentists with Minimal Training in Spectrophotometer Utilization

OBJECTIVES: To determine whether: (1) dentists with minimum training in spectrophotometer (SP) usage obtain the same shade measurements as those with extensive training, (2) significant differences are found in shade measurements obtained by group of minimally trained dentists, and (3) a dentist's body posture influences shade measurements. METHODS: After 10-15 minutes of training in the use of a spectrophotometer (Crystaleye, Olympus, Japan) given by an investigator with extensive training, ten dentists recorded the CIE L*a*b* coordinates for the cervical, middle, and incisal thirds of six natural teeth embedded in maxillary and mandibular typodonts of three manikins (KaVo, Germany). Measurements were taken thrice from two vantage points (standing and sitting). Cervical, body, and incisal DL*a*b* and DEs were computed with reference measurements those obtained by the experienced investigator. RESULTS: Intraclass correlation coefficients for measurements taken thrice, were high (>0.9), therefore, the computed means were used for analyses. Mean cervical, body, and incisal L*a*b* values were similar for the 10 clinicians (ANOVAs, p>0.05); standing or sitting showed little difference (t-tests, p>0.05). Table lists percentage of dentists obtaining DE values above and below clinically noticeable 3.6 threshold; most were above 3.6.

			DE cervical		DE body		DE incisal
Position	Tooth	Manikin	<3.6	>3.6	<3.6	>3.6	<3.6	>3.6
Standing	Maxillary central incisor	1	67%	33%	78%	22%	78%	22%
		2	78%	22%	100%	0%	100%	0%
		3	89%	11%	100%	0%	100%	0%
	Mandibular lateral incisor	1	100%	0%	100%	0%	100%	0%
		2	89%	11%	100%	0%	89%	11%
		3	100%	0%	100%	0%	100%	0%
Sitting	Maxillary central incisor	1	70%	30%	80%	20%	70%	30%
		2	90%	10%	100%	0%	80%	20%
		3	100%	0%	100%	0%	100%	0%
	Mandibular lateral incisor	1	90%	10%	80%	20%	70%	30%
		2	30%	70%	100%	0%	100%	0%
		3	100%	0%	100%	0%	100%	0%

CONCLUSION: Even with minimal training and regardless of body posture dentists can obtain consistent shade measurements using a spectrophotometer.