Does the severity of untreated dental caries of preschool children influence the oral health-related quality of life?

AIM: To assess the impact of untreated dental caries and its severity on the oral health-related quality of life (OHRQoL) of Kuwaiti preschool children and their caregivers. METHODS: Participants were 4- and 5-year-old kindergarten children attending preselected public schools from one of the Governorates in Kuwait. Early childhood caries (ECC) was evaluated by clinical examinations and presented using decayed, missed, filled teeth/surface (dmft/dmfs). The clinical consequences of untreated dental caries were assessed using the pufa (pulp, ulcers, fistula, abscess) index for primary teeth. A structured questionnaire obtained demographic information of children and their caregivers. OHRQoL was assessed using the Arabic version of Early Childhood Oral Health Impact Scale (A-ECOHIS). RESULTS: Among the 334 participants, 171 were kindergarten level-1 (KG1), and 163 were level-2 (KG2). The overall prevalence of dental caries was 78.9% for KG1 children and 67.4% for KG2 children. Decayed teeth were the main component for both dmft (84%) and dmfs (68%). The total mean (SD) pufa score was 0.54 (1.5), and about 19.2% of participants had at least one tooth with pufa > 0. A total of 207 A-ECOHIS were completed. Both family and child impact scores were significantly higher for children with a dmft score of 1 or more (p < 0.001) or with one or more pufa (p < 0.001). Child impact section scores were significantly higher with the increasing degrees of untreated caries (dt) (p = 0.004). CONCLUSION: The severity of untreated dental caries and caries experience had a negative impact on the OHRQoL of Kuwaiti preschool children and their families. Using the pufa index had provided additional information about the effect of the caries severity on the OHRQoL than assessing the caries experience alone. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12903-023-03274-7.