Periodontal Screening and Recording (PSR) Index Scores Predict Periodontal Diagnosis

Research Article

J Dent App. 2014;1(1): 8-12.

Periodontal Screening and Recording (PSR) Index Scores Predict Periodontal Diagnosis

Primal KS1, Esther SR2 and Boehm TK3*

1OSF Health Care, 530 NE Glen Oak Avenue, Peoria, Illinois 61637, USA

2University of Minnesota School of Dentistry, Moos Tower, 515 Delaware St. SE, Minneapolis, Minnesota 55455, USA

3College of Dental Medicine, Western University of Health Sciences, 309 E Second Street, Pomona, CA 91766, USA

*Corresponding author: Boehm TK, College of Dental Medicine, Western University of Health Sciences, 309 E Second Street, Pomona, CA 91766, U.S.A

Received: June 10, 2014; Accepted: June 17, 2014; Published: June 19, 2014


Objective: The objective of this study was to determine the probability of periodontal disease diagnosis given the highest Periodontal Screening and Recording Index (PSR) encountered during a screening exam. Diagnostic characteristics of the PSR in a large number of adults attending a dental school clinic were determined.

Materials and Methods: In this cross-sectional study of 2299 adult patients attending a dental school clinic, PSR scores were correlated to periodontal diagnoses based on attachment levels, and sensitivity, specificity, predictive value of the PSR were determined.

Results: The highest PSR score correlated well with eventual periodontal diagnosis and PSR scores display high specificity in regards to periodontal diagnosis. Patients with PSR scores of zero are most likely periodontally healthy with no history of attachment loss (in 93% of cases); PSR scores less than 3 most likely indicate plaque-induced gingivitis (79% of cases), and a PSR score of 4 usually indicates chronic periodontitis (81% of cases).

Conclusions: Although not intended for diagnosis, PSR scores can be used to predict periodontal diagnosis. This also applies to CPITN scores as the scoring system is the same, and known diagnostic characteristics of the CPITN are similar to the diagnostic characteristics of the PSR observed in this study.

Keywords: Epidemiology; Gingivitis; Chronic periodontitis


AAP: American Academy of Periodontology; CPITN: Community Index of Periodontal Treatment Needs; NHANES: National Health and Nutrition Examination Survey; PSR: Periodontal Screening and Recording Index.


Diagnosis of periodontal disease often involves a comprehensive periodontal exam including full mouth probing and measurement of attachment levels. Since these examsare time intensive and often require a dental assistant for charting,epidemiologic studies often use the Community Periodontal Index of Treatment Needs (CPITN) as defined by Ainamo et al. [1], to estimate periodontal disease and treatment needs. For the same reasons, it appears that general dentists tend not to perform full periodontal exams [2], and it has been suggested that general dentists should use the CPITN to facilitate identification of periodontal disease [3]. Following this suggestion, the American Dental Association and American Academy of Periodontology developed the Periodontal Screening and Recording Index (PSR)to improve periodontal disease detection and collaboration between general dentists and periodontists. The PSR is derived from the CPITN, uses the same specialized probe [4] and scoring system [5], and involves probing of all teeth. Based on the site with the worst probing depth, calculus and gingival bleeding, scores are assigned to each sextant. It has been suggested that for patients with none or mild periodontal disease (scores 0 to 2), PSR scores may suffice as periodontal record, whereas PSR scores of 3 (highest probing depth 5.5 mm) in two or more sextants, or a PSR score of 4 (probing depth greater than 5.5 mm) in any sextant would warrant further periodontal assessment [6], although the scientific evidence for this suggestion is unclear.

Even though PSR and CPITN systems may be useful for screening purposes, scores are not diagnostic since neither system measures clinical attachment levels. To our knowledge, no study exists that correlates PSR and CPITN scores to periodontal diagnoses based on attachment levels. In order to correct this deficit, we determined in this cross sectional study of adults attending a large general practice dental clinic the correlation between highest PSR score and periodontal diagnosis. Along with diagnostic probabilities of each PSR score, we also determined prevalence, predictive values, sensitivity, specificity, and reliability for the PSR system, as existing data is limited. Findings from this study should allow clinicians to predict the likelihood of certain periodontal diseases based on PSR scores alone, and allow periodontal disease prevalence estimates from epidemiologic studies that report PSR and CPITN scores.

Materials and Methods


This study was a retrospective study of records from 3426 individuals who registered as patients at the Western University of Health Sciences Dental Center between September 2010 and April 2013. Records were excluded from this study for the following reasons: patient was unable to provide consent for examination, treatment, and use of records for research; patient did not receive a complete oral examination including PSR and periodontal diagnosis; patient was edentulous resulting in no PSR scores and periodontal diagnosis.

After applying exclusion criteria, 2299 patient records were reviewed to determine PSR-periodontal diagnosis correlation. Demographic information, medical history and dental findings were also retrieved to test if the dental school clinic's patient population was representative of the community at large. The study was approved by the Western University of Health Sciences Institutional Review Board (IRB#12/IRB/019) and has been conducted in full accordance with ethical principles outlined in the Declaration of Helsinki.


The Dental Center is a dental school clinic that was designed to mimic a large general dentistry group practice, and advertised as such attracting patients with general dentistry needs. Pairs of third and fourth year dental students provided basic patient care similar to a dental assistant-associate dentist pairing, and a licensed general dentist managing and supervising six student pairs. For examination and diagnosis, students examined a patient and assigned a diagnosis, which was then verified by a supervising dentist. As part of gaining clinic privileges, students and dentists were calibrated on performing PSR assessments and periodontal exams using slide presentations and video clips by a periodontist (TB). Dentists, students and periodontists were also calibrated by TB to use same amount of probing force (20g) using a letter scale (Escali, Minneapolis, Wisconsin) as part of initial calibration, and randomly thereafter.To ensure continued calibration, periodontist TB also randomly calibrated dental students and dentists individually throughout the years of this studyon live patients, and audited all patient records for diagnostic consistency.

Examination Procedure and Periodontal Diagnosis

Prospective patients were initially seen for a screeningexam to determine if their treatment needs could be met at the Dental Center, and this screening included a first PSR assessment. If accepted for treatment, patients would be seen for a comprehensive oral exam that included a second PSR assessment, and periodontal diagnosis based on attachment level as outlined in supplemental table S1, and following largely the current periodontal disease definitions as outlined by the 1999 International Workshop Classification of Periodontal Disease [7]. Both PSRs were used to determine interexaminer reliability of PSR measures, and the highest PSR score determined the comprehensive exam correlated with periodontal diagnosis made by periodontist TB.

Periodontist TB determined periodontal diagnosis by measuring attachment levels independently from the general dentist/student team either at the exam appointment, or at a subsequent appointment within a few weeks of the exam. Diagnosis made by the general dentist/student team and the periodontists were used to determine inter-examiner diagnostic reliability.

Statistical analysis

For assessment of inter-examiner reliability, we determined kappa by correlating American Academy of Periodontology Disease (AAP) Categories assigned independently by the dentist/student team and the periodontist, and by correlating PSR scores measured during the screening exam and during the subsequent comprehensive exam.

In addition, contingency tables for various periodontal disease diagnoses and PSR scores were constructed to determine probability of diagnosis, receiver-operator curves, sensitivity, specificity and predictive values. For tabulation of data we used Microsoft Excel 2010 (Redmond, WA), and analyzed the data using GraphPad Prism 6.02 (LaJolla, CA).


Calibration of the different providers regarding periodontal diagnosis was nearly ideal as determined by correlating diagnoses made by the periodontist and the general dentist/student teams. Interexaminer agreement was very good (examiners agreed 95% on diagnoses, kappa was 0.936 with a standard error 0.012; Pearson coefficient was 0.968 (95% confidence interval 0.962 to 0.972). If there was disagreement, assigned AAP categories were only off by one category most of the time. Therefore, we concluded that there was little disagreement between the periodontist and calibrated general dentist/student teams, and that the diagnostic process was extremely reliable.

Calibration of the different providers regarding PSR scoring was successful as PSRs determined by different providers at separate appointments did not differ on average between appointments (Table 1). Interexaminer agreement between PSR scores was good (examiners agreed 76% of observations, kappa=0.643 with standard error of 0.017; Pearson r coefficient was 0.8002 (95% confidence interval 0.7796 to 0.8190)). If there was disagreement, PSR scores were usually only off by a score of one, and agreement increased with increasing PSR scores (Table 1). Based on our PSR data and subsequent probing depth data, we estimated the chance of missing a pocket deeper than 5 mm during a PSR screening to be 0.9%