PUFA Index was introduced to detect the clinical consequences of untreated dental caries. To date, there are no studies on the reliability and accuracy of the PUFA index as a screening tool. Other than indices, radiographs were sometimes used as a screening tool using the validated Periapical Index (PAI). The aim of this study was to evaluate the reliability and accuracy of PUFA and PAI in screening for clinical outcomes of untreated caries, specifically pulpal and periapical diseases. The reference standard is the clinical diagnosis, as categorized by the American Association of Endodontists. Intra- and inter-examiner reliability will be determined using Cohen's kappa. Sensitivity, specificity, positive predictive value, and negative predictive value will be calculated. Receiver Operating Characteristics (ROC) contrast estimation will be computed to compare the two index tests.

The index of decayed-missing-filled permanent teeth (DMFT) records decayed (D), missing (M), or filled (F) teeth in an individual, but it fails to give information about the clinical outcomes of untreated dental caries. A new index complements the DMFT index by recording the advancement of the caries lesion into surrounding tissues, including pulpal involvement (P), ulceration due to tooth fragments (U), fistula formation (F) and abscess (A). The PUFA index has yet to be validated in the adult population. Other than indices, radiographs were sometimes used as a screening tool using the validated Periapical Index (PAI). Hence, the aim of this study is to evaluate the reliability and accuracy of PUFA and PAI in screening for clinical outcomes of untreated caries, specifically pulpal and periapical diseases. The study will be carried out in Primary Care Clinic, Faculty of Dentistry, Universiti Kebangsaan Malaysia. Consecutive sampling will be used; all eligible patients are invited to participate. The inclusion criteria are as follow:

i. New patient, not receiving active dental treatment at the time of study ii. Adult patient (18 years old or above) iii. Having at least 12 teeth in the oral cavity iv. Presented with the clinical situation for which radiograph(s) were indicated v. No radiograph was taken within the last six months The reference standard is the clinical diagnosis, as categorized by the American Association of Endodontists. A comprehensive examination will be carried out for each tooth, followed by investigation using orthopantomography (OPG), periapical radiograph, periodontal probing, heat test, cold test, electric pulp tester when indicated, to aid in arriving at the definitive diagnosis.

Two independent, trained dentists are employed to screen the participants using DMFT and PUFA indices, blinded to the clinical diagnosis and PAI scoring. The examination is done using only a mouth mirror.

Another two independent, trained dentists, blinded to the clinical diagnoses and the PUFA scoring, will score each tooth on the orthopantomograph for the periapical status using the Periapical Index (PAI).

The outcome of PUFA is dichotomized as Positive (PUFA>0) or Negative (PUFA=0) for each tooth. Similarly, the PAI was dichotomized as Positive (PAI≥3) or Negative (PAI<3). Intra- and inter-examiner reliability will be determined using Cohen's kappa. Sensitivity, specificity, positive predictive value, and negative predictive value will be calculated. ROC contrast estimation will be computed to compare the two index tests.

Inclusion Criteria:

• New patient, not receiving active dental treatment at the time of the study
• Adult patient (18 years old or above)
• Has at least 12 teeth in the oral cavity
• Presented with the clinical situation for which radiograph(s) were indicated (American Dental Association 2012)
• No radiograph was taken within the last 6 months

Exclusion Criteria:

• Pregnant
• Medically compromised (American Society of Anesthesiologists ASA3)