Validation of PUFA Index in Assessing Untreated Dental Caries Among Malaysian Adult Subpopulation
Phase: NA
Conditions: Pulpitis, Apical Periodontitis
Sponsor: Universiti Kebangsaan Malaysia Medical Centre

 
 
 
 
 
 
 
Validation of PUFA Index in Assessing 
Untreated Dental Caries Among Malaysian 
Adult Subpopulation  
 
RESEARCH PROTOCOL 
10 September 2015 

Introduction 
Dental caries is considered a major factor of tooth ache and tooth loss in population all over the 
world (Fejerskov & Kidd 2003). In the year 2000, 90% of the adult Malaysian population had been 
reported to be living with caries (Oral health Division, Ministry of Health, Malaysia 2011). Dental 
caries in its advanced stages may influence the health and quality of life, causing pain, disturbances 
in sleeping patterns, eating difficulties, and reduced body weight (Jorge et al. 2014). In severe 
cases, it might even lead to hospitalization (Figueriredo et al. 2011). In many developing nations, 
access to oral health service is extremely restricted and teeth are often left untreated or extracted 
because of pain or discomfort (Peterson 2003). 
Traditionally, information on caries has been gathered by utilizing the DMFT index. The 
DMFT Index is expressed as the total number of teeth that are decayed (D), missing (M), or filled 
(F) in an individual. This established index provides information on the presence of caries, the 
restorative needs and any surgical intervention performed on a patient (Larmas 2010). The 
drawback of DMFT is that it fails to give information about the clinical outcomes of untreated 
dental caries. A deep caries cavity with pulpal involvement is still considered as decayed and 
pulpal involvement is not mentioned at all in the caries scoring system.  
Hence, a new index was developed to record the full continuum of untreated dental caries. 
The PUFA 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) (Monse et al. 2010). Ideally, this index should reflex the 
underlying pulpal and periapical involvement of the carious lesion, thereby serving as a screening 
tool for further clinical and radiographic examinations to diagnose an pulpal and periapical 
diseases. 

The PUFA index had been used in prevalence study among Philipino (Monse et al. 2010), 
Polish (Baginska et al. 2013) and Indian (Mehta & Sumatibhalia 2014) children. The 
reproducibility of the index was good, with intraexaminer kappa value of 0.85 and intraexaminer 
kappa values ranging from 0.80 to 0.97 (Monse et al. 2010). Despite that, currently the capability 
of the index in meeting the intended purpose of capturing the clinical sequelae of untreated dental 
caries was not assessed. This limits its use in triaging patients in a large practice, or in 
epidemiological survey (prevalence study) of a population. Therefore, it is paramount to ensure 
the index performs adequately as a screening tool when compare to conventional clinical 
procedures in disease detection. Furthermore, the PUFA index should also be tested in an adult 
population since the existing literature focused only on children. 
Besides PUFA, variants of indices using the same concept were developed. In an attempt 
to simplify PUFA, Pulpal Involvement-Roots-Sepsis (PRS) Index was modified by redefining P 
as caries process reached pulp chamber, R as non-restorable caries. Also, Fistula and Abscess were 
combined as S (Baginska & Stokowska 2013). On the other hand, the Caries Spectrum and 
Treatment (CAST) Index was developed to combine both ICDAS II and PUFA (Frecken et al. 
2011), but this resulted in a complex index with ten codes. 
Other than indices, more accurate measurements such as radiographs were sometimes used 
as a screening tool for pulpal and periapical diseasess. In fact, radiological assessment is crucial 
because chronic apical periodontitis often develops without subjective symptoms (Huumonen & 
Ørstavik 2002).  However, there is no standard criteria for the registration of apical periodontitis 
in surveys and epidemiological study, either for periapical radiographs or panoramic radiographs. 
This makes comparison between studies difficult. With the validated Periapical Index (PAI), 
calibrated observers could use it for such purpose (Huumonen & Ørstavik 2002). Nevertheless, 

periapical and panoramic radiographs were reported with high specificity (0.98 and 1.00, 
respectively) but low sensitivity (0.55 and 0.28, respectively) when compared against CBCT 
(Estrela et al 2008). Hence, the use of these conventional imaging tends to detect only advanced 
lesions and therefore underestimate disease prevalence.  
Apart from the issue of accuracy, the use of panoramic radiographs were controversial, 
especially in striking a balance between increased radiation exposures, cost to the health care 
system and diagnostic yield (Rushton et al. 2001). Panoramic radiographs, in combination with a 
limited number of intra-oral radiographs, yield good diagnostic information with low radiation 
dose (Molander et al 1993). Therefore, many dentists reported using it for screening oral diseases 
in new patients (Rushton et al 1999). Although many radiological findings could be observed on 
panoramic radiographs, Rushton et al. (2001) argued against its use because the findings are also 
revealed on bitewing radiographs, or are often not contributive towards treatment planning.  
 
Problem Statement 
The PUFA index complements the widely used DMFT index by recording the 
advancement of the caries lesion into surrounding tissues, which includes pulpal involvement (P), 
ulceration due to tooth fragments (U), fistula formation (F) and abscess (A). However, this new 
index has yet to be validated, hence limits its use in prevalence study. On the hand, despite the 
importance of radiological diagnosis, screening pulpal and periapical diseases using panoramic 
radiographs (orthopantomographs OPG) are plagued with issues of accuracy and radiation risk. 
Therefore, comparison of the two screening methods, using PUFA index or panoramic radiograph, 
will inform clinicians and researchers in selecting the appropriate tool for screening pulpal and 
periapical diseases. 

 
Research Questions 
a. How reliable is the PUFA in screening pulpal and periapical diseases? 
b. How reliable is the PAI in screening pulpal and periapical diseases? 
c. How accurate is the PUFA in screening pulpal and periapical diseases? 
d. How accurate is the PAI in screening pulpal and periapical diseases? 
e. Is there a difference in the accuracy of PUFA and PAI in screening pulpal and periapical 
diseases? 
 
Hypotheses 
a. The PUFA index is highly reliable in screening pulpal and periapical diseases. 
b. The PAI is highly reliable in screening pulpal and periapical diseases. 
c. The PUFA index is highly accurate in screening pulpal and periapical diseases. 
d. The PAI is highly accurate in screening pulpal and periapical diseases. 
e. There is a difference in the accuracy of PUFA and PAI in screening pulpal and periapical 
diseases. 
 
 
 
 
 
 
 

 
 
 
Research Objective 
General Objective: 
To evaluate the reliability and accuracy of PUFA and PAI in screening for clinical outcomes of 
untreated caries, specifically pulpal and periapical diseases. 
 
Specific Objectives: 
a. To determine the intra- and inter-examiner reliability of PUFA in screening pulpal and 
periapical diseases. 
b. To determine the intra- and inter-examiner reliability of PAI in screening pulpal and periapical 
diseases. 
c. To determine the sensitivity, specificity and predictive values of PUFA in screening pulpal and 
periapical diseases. 
d. To determine the sensitivity, specificity and predictive values of PAI in in screening pulpal 
and periapical diseases. 
e. To compare the accuracy of PUFA and PAI in screening pulpal and periapical diseases. 
 
 

Methods 
Participants 
The study will be carried out in Primary Care Clinic, Univeristi 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 the study 
ii. Adult patient (18 years old or above) 
iii. Has at least 12 teeth in the oral cavity 
iv. Presented with the clinical situation for which radiograph(s) were indicated (American 
Dental Association 2012) 
v. No radiograph was taken within the last 6 months 
At the time of this study, the UKM dental clinic routinely ordered OPG for patients with multiple 
dental problems, particularly if they need periodontal, prosthodontic, orthodontic treatment or oral 
surgery. Hence, only patients who required OPG according to the screening procedure of this 
institution is included. Pregnant or medically compromised patients (American Society of 
Anesthesiologists ASA3) will be excluded.  
Sample size is estimated using the method described in Buderer (1996). Based on the systematic 
review, the prevalence of periapical radiolucency was about 5% (Pak et al 2012). As there was no 
prior data, the sensitivity of PUFA was assumed conservatively at 0.50 and specificity at 0.80. 
Therefore, a total of 1921 and 65 teeth are required, based on the assumed sensitivity and 
specificity, respectively. Since each patient must have at least 12 teeth, 161 patients will be 
sufficient for estimation of both sensitivity and specificity. Assuming 2% of the radiographs have 

overlapped images, poor contrast or poor quality, the sample size was adjusted to a total of 165 
patients. 
The unit of interest for analysis is at tooth level. A tooth is considered present in the mouth when 
any part of it was visible. The teeth excluded for scoring are unerupted teeth, congenitally missing 
teeth or supernumerary teeth, teeth removed for reasons other than dental caries, and primary teeth 
retained in the permanent dentition. 
 
Reference Standard 
The reference standard is the clinical diagnosis. This will be carried out by an endodontic 
postgraduate student, using the diagnostic criteria of AAE. Comprehensive examination will be 
carried out for each tooth, followed by investigation using OPG, periapical radiograph, periodontal 
probing, heat test, cold test, electric pulp tester when indicated, to aid in arriving at the definitive 
diagnosis. To observe the As Low As Reasonably Achievable (ALARA) principle, additional 
periapical radiographs were taken only when radiographic assessment is impossible with the OPG 
because of overlapping, blurred images or obscured periapical region. Because OPG has lower 
sensitivity than periapical radiograph in detecting apical periodontitis, periapical radiograph is also 
taken when periapical lesion cannot be seen on OPG but a tooth is having large caries or showing 
signs and symptoms of pulpal and periapical diseases. At the end of this comprehensive 
examination, each tooth will have pulpal and apical diagnoses. 
 
Index Test 1: PUFA 

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. Each tooth was scored either Decayed, Missing or Filled.  
If the tooth is present, PUFA scoring is done. A particular tooth can be scored as either one of 
Normal, Pulpal involvement, Ulceration, Fistula or Abscess. In case of doubt concerning the extent 
of odontogenic infection, the basic score (Pulpal involvement) is given.  Lesions in the surrounding 
tissues that are not related to a tooth with visible pulpal involvement as a result of caries are not 
recorded. 
 
Index Test 2: PAI 
The OPG will be taken for all participants by qualified radiographers using Sirona Orthophos 
(Sirona Dental System GmbH, Bensheim, Germany). All radiographs will be evaluated by two 
trained dentists, blinded to the clinical diagnoses and the PUFA scoring. Each tooth is scored for 
the periapical status using the Periapical Index (PAI) proposed by Ørstavik et al (1986). 
 
Ethical consideration 
Ethics approvals will be obtained from the research ethics committee of the university. The 
research will be conducted in accordance with the Declaration of Helsinki. Informed consent will 
be obtained from all participants in written form. Emergency treatment will be carried out if the 
patient is in pain or showing sign of systemic spread of infection (e.g. swelling, fever). Following 
the study, all participants will be arranged for appropriate treatment. 
 
Data analysis 

The demographic data of the patients will be analyzed using descriptive statistics. Mean DMFT 
and PUFA scores will be calculated. The assessment of the teeth will be tabulated.  
The pulpal diagnosis and apical diagnosis for each tooth will be dichotomized as Disease or No 
Disease. To determine the accuracy of the test, 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. To compare the two index tests, ROC contrast estimation will be computed. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

References 
Monse B, Heinrich-Weltzien R, Benzian H, Holmgren C, van Palenstein Helderman (2010) PUFA 
– An index of clinical consequences of untreated dental Caries. Community Dentistry Oral 
Epidemiology 38, 77–82. 
Fejerskov O, Kidd EAM (2003) Dental caries: the disease and its clinical management. Second 
Edition, Denmark. Blackwell Monksgaard. 
Oral health division, Ministry of Health Malaysia (2011) National Oral Health Plan for Malaysia 
2011–2020. 
Figueieredo MJ, de Amorim RG, Leal SC, Mulder J, Frencken JE (2011) Prevalence and severity 
of clinical consequence of untreated dentine carious lesion in children from a deprived area in 
Brazil. Caries Research 45, 435–42. 
Petersen PE. The World Oral Health Report (2003) Continuous improvement of oral health in the 
21st century –the approach of the WHO Global Oral Health Programme. Community Dentistry 
Oral Epidemiology 15, 3–24 
Larmas M (2010) Has dental caries prevalence some connection with caries index values in adults? 
Caries Research 44, 81–4. 
Baginska J, Rodakowska E, Wilezynska-Borawska M (2013) Index of clinical consequences of 
untreated dental caries (pufa) in primary dentition of children from north-east Poland. Advances 
in Medical Sciences 58, 442–7.  
Mehta A, Sumatibhalia (2014) Assessing consequences of untreated dental carious lesions using 
pufa index among 5-6 years old school children in an urban Indian population. Indian Journal of 
Dental Research 25, 23–7. 

Baginska J, Stokowska W (2013) Pulpal involvement-roots-sepsis index: A new method for 
describing the clinical consequences of untreated dental caries. Medical Principles and Practice 
22, 555–60. 
Frencken JE, de Amorim RG, Faber J, Leal SC (2012) The Caries Assessment Spectrum and 
Treatment (CAST) index: Face and content validation. International Dental Journal 62, 270–6. 
Huumonen S, Ørstavik D (2002) Radiological aspects of apical periodontitis. Endodontic Topics 
1, 3–25.   
Estrela C, Bueno MR, Leles CR, Azavedo B, Azevedo JR (2008) Accuracy of cone beam 
computed tomography and panoramic radiography for detection of apical periodontitis. Journal of 
Endodontics 34, 273–9. 
Rushton VE, Horner K, Worthington HV (2001) Screening panoramic radiology of adults in 
general dental practice: radiological findings. British Dental Journal 190, 495–501. 
Molander B, Ahlqwist M, Gröndahl HG, Hollender L (1993) Comparison of panoramic and 
intraoral radiography for the diagnosis of caries and periapical pathology. Dentomaxillofacial 
Radiology 22, 28–32. 
Rushton VE, Horner K, Worthington HV (1999) Aspects of panoramic radiography in general 
dental practice. British Dental Journal 186, 342–4. 
American Dental Association, Food and Drug Administration (2012) Dental radiographic 
examinations: recommendations for patient selection and limiting radiation exposure. Pp.5–7. 
Buderer NM (1996) Statistical methodology: I. Incorporating the prevalence of disease into the 
sample size calculation for sensitivity and specificity. Academic Emergency Medicine 3, 895–900. 
Pak JG, Fayazi S, White SN (2012) Prevalence of periapical radiolucency and root canal treatment: 
a systematic review of cross-sectional studies. Journal of Endodontics 38, 1170–6. 

Ørstavik D, Kerekes K, Eriksen HM (1986) The periapical index: a scoring system for 
radiographic assessment of apical periodontitis. Endodontics & Dental Traumatology 2, 20–34. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Data analysis 
Appendix 1. Flow chart 
 
 
 
 
 
 
 
 
 
 
 
Patient attending 
Primary Care Clinic
Screening with Indices
- DMFT
- PUFA
Screening with dental 
panoramic radiographs
- PAI
Clinical diagnosis
- Pulpal diagnosis
- Periapical diagnosis
Inclusion: 
New patient
≥ 18 years old
At least 12 teeth
Radiograph(s) indicated 
(ADA 2012)
No radiograph taken within 
the last 6 months
Exclusion:
Pregnant
Medically compromised 
(ASA 3)

Appendix 2. Dummy tables 
A total of x patients were invited to participate.  
X fulfill the inclusion criteria.  
X declined to participate because …… 
 
Table 1. Demographic distribution of the patients examined 
 
Count (%) 
Mean (SD) 
Total number of patient assessed 
 
 
Gender 
Male 
 
 
Female 
 
 
Age  
Age 
 
 
DMF 
Decayed  
 
 
Missing 
 
 
Filled 
 
 
DMFT 
 
 
DMFT > 0 
 
 
PUFA  
Pulpal involvement 
 
 
Ulceration 
 
 
Fistula 
 
 
Abscess 
 
 
PUFA 
 
 
PUFA > 0 
 
 
 
 
 
 
 
 

Table 2. Distribution of teeth assessed using DMFT, PUFA, PAI, Pulpal Diagnosis and 
Periapical Diagnosis 
 
Count 
Percent 
Total number of teeth assessed 
 
 
DMFT 
Decayed 
 
 
Missing 
 
 
Filled 
 
 
PUFA 
Pulpal involvement 
 
 
Ulceration 
 
 
Fistula 
 
 
Abscess 
 
 
PAI 
1 
 
 
2 
 
 
3 
 
 
4 
 
 
5 
 
 
Pulpal diagnosis 
Normal pulp 
 
 
Reversible pulpitis 
 
 
Symptomatic irreversible pulpitis 
 
 
Asymptomatic irreversible pulpitis 
 
 
Pulp necrosis 
 
 
Previously treated tooth 
 
 
Previously initiated therapy 
 
 
Apical diagnosis 
Normal apical tissue 
 
 
Symptomatic apical periodontitis 
 
 
Asymptomatic apical periodontitis 
 
 
Chronic apical abscess 
 
 
Acute apical abscess 
 
 
Condensing osteitis 
 
 
 
 

Table 3. Intra- and inter-examiner reliability (Cohen’s kappa) of DMFT, PUFA and PAI 
 
DMFT 
PUFA 
PAI 
Intra-examiner reliability 1 
 
 
 
Intra-examiner reliability 2 
 
 
 
Inter-examiner reliability  
 
 
 
 
Table 4. Accuracy of PUFA and PAI 
 
Gold Standard = Pulpal Diagnosis 
Gold Standard = Periapical Diagnosis 
 
PUFA 
PAI 
PUFA 
PAI 
TP 
 
 
 
 
FN 
 
 
 
 
TN 
 
 
 
 
FP 
 
 
 
 
Sensitivity 
 
 
 
 
Specificity 
 
 
 
 
PPV 
 
 
 
 
NPV 
 
 
 
 
 
Table 5. ROC contrast estimation  
Gold 
Standard 
Contrast 
Estimate 
SE 
95% Wald 
Confidence Limits 
Chi-
square 
P 
Lower 
Upper 
Pulpal 
diagnosis 
PUFA-
PAI 
 
 
 
 
 
 
Periapical 
diagnosis 
PUFA-
PAI