Table 2.

Description of key methodologies and findings reported in studies that used an open-ended methodology.

Publication Title	Author (Year of Publication) Location	Sample Group (Sample Size)	Methodology: Pre-testing, Reliability	Mode of WTP elicitation	Results (key findings on WTP)
Baseline Characteristics and Treatment Preferences of Oral Surgery Patients	Atchison, K. A., Gironda, M.W. et al (2007) USA	Patients (98 - mandibular fracture, 105 - third molar)	-	Questionnaire (form)	Patients receiving treatment for mandibular fractures (Median(SD)=$37.4K(31.2K)) were willing to pay more for a special treatment to restore function for a jaw fracture without scarring or nerve damage than patients scheduled for third molar removals (Median(SD)=$30.6K(28.7K)).
Cost effectiveness of personalized plaque control for managing the gingival manifestations of oral lichen planus	Stone, S. J., McCracken, G.I. et al (2013) UK	Patients (39 - intervention group)	-	Questionnaire	All patients stated a positive maximum WTP value (range £65–£1500).
Evaluation of three methods assessing the relative value of a dental program	Tuominen, R. (2008) Finland	Medical/Dental Students (120 - medical, 36 - dental)	-	Questionnaire (written)	Respondents were willing to make the highest donations for running the helicopter ambulance service (38.90 euros) and least for the dental check-up programme for 7-year-olds (14.34 euros). An independent sample T-test reported a statistically significant difference (p<0.01).
Implant Overdentures for edentulous elders: study of patient preferences	Esfandiari, S., Lund, J.P. et al (2009) Canada	Patients (23 - implant overdenture, 13 - conventional denture)	-	Face-to-face interview	Wilcoxon signed rank test reported that the median supplemental amount above $1200 for another type of denture that the implant group would pay for an implant-supported denture was $1000 (range $100-3800), which was significantly higher (p<0.001) than that for the conventional denture group ($300). 89% of respondents were willing to pay more to receive implant treatment if they could make monthly instalments.
The value of caries preventive care among 19-year olds using the contingent valuation method within a cost-benefit approach	Oscarson, N., Lindholm, L. et al (2007) Sweden	Adolescents (30 - high risk group, 52 – control group)	Pilot test interview (5 participants)	Questionnaire	Linear regression models showed that the mean monthly WTP for preventive dental care among those with high caries risk (117.12SEK) was significantly higher than those with low caries risk (90.58SEK) (B(SE)=26.54(12.22); p=0.03). Net social benefit was >0.
Willingness and ability of Bulgarian consumers to pay for improved public health care services	Pavlova, M., Groot, W. et al (2004) Bulgaria	General public (990)	Questionnaire tested in pilot study	Face-to-face interview	WATP (Willingness and Ability To Pay) for a dental check-up (Median=2.00BGL; Mean=2.67BGL; SD=2.75) was lower than that for filling/treatment of a tooth (Median=10.00BGL; Mean=11.44BGL; SD= 9.24), extraction of a tooth (Median=10.00BGL; Mean=9.58BGL; SD=8.73), and placement of dental prostheses (Median=15.00, Mean=15.85; SD=15.01). Based on Tobit regression, a higher family budget was associated with a higher WATP for a dental check-up (β(SE)=0.0005(0.000); p<0.05), a filling (β(SE)=0.0005(0.000); p<0.05), an extraction (β(SE)=0.0005(0.000); p<0.05), and the placement of dental prostheses (β(SE)= 0.0004(0.000); p<0.05). Staying in a village rather than in the city was associated with a lower WATP for filling (β(SE)=-0.1057(0.035); p<0.05) and extraction (β(SE)=-0.1320(0.041); p<0.05
Willingness and ability to pay for unexpected dental expenses by Finnish adults	Widström, E. & Seppälä, T. (2012) Finland	General public (704)	-	Questionnaire (postal)	For immediate replacement of a lost filling, 93.2% of respondents were willing to pay the lower price charged in the Public Dental Service and 46.2% were willing to pay the private fee. Logistic regression analysis for willingness to pay the same or a higher price than the replacement of a lost filling would have cost (after reimbursement) in the private sector (80 €) showed that a higher yearly income (EUR 25 to >50k) was positively associated with WTP [25-50k vs <10k] (B(95% CI)=1.254(0.247-2.261); p=0.02); [>50k vs <10k] (B(95% CI)=1.893(0.761-3.025); p=0.001).
Willingness to pay for dental fear treatment. Is supplying dental fear treatment socially beneficial?	Halvorsen, B. & Willumsen, T. (2004) Norway	Patients (62)	-	Telephone survey	While only 24% of the patients were willing to pay the actual cost of the treatment before attending, 71% were willing to pay afterwards. Ordinary least squares regression reported that higher incomes, benefits from dental treatment (B=1041; p<0.05), and changes in dental health capital [treated surfaces] (B=165; p<0.01) were significantly associated with WTP for dental/dental fear treatment.
Willingness to pay for dentin regeneration in a sample of dentate adults	Birch, S., Sohn, W. et al (2004) USA	General public (611)	Test–retest reliability (40 adults)	Questionnaire (Computer aided home interview, self-administered questionnaire)	At a success rate of 95%, the mean WTP for dentin regeneration was $262.70 (non-insured subjects) and $11.00 per month (insured subjects). For a success rate of 75%, the corresponding values were $210.90 and $9.20 per month. Linear regression analysis showed that while regular dental visit was significantly associated with WTP for dentin regeneration among non-insured subjects (β(SE)=95.2(44.7); p=0.03), individuals’ valuations of treatments involve substantial unexplained variation.