Evaluation of simple periodontal screening technique currently used in the UK armed forces

The need to prioritise resources for periodontal care within the UK Armed Forces has led to the development and introduction of a simple periodontal screening technique, the Periodontal Index for Treatment (PIT), based upon the clinical assessment of six teeth (all first molars and the maxillary right and mandibular left central incisors) with a specially designed periodontal probe (the PIT probe) and the use of bitewing radiography. This paper describes the evaluation of the technique. This was carried out by examining 406 subjects aged from 16 to 64 yr in four groups. All subjects received a full mouth periodontal assessment, performed by one of two periodontists with standardised bitewing radiography of their premolar and first and second molars. They were then categorised as periodontally healthy (PIT 0), with gingivitis but no pocketing exceeding 4 mm (PIT 1), with pocketing 4-5 mm (PIT 2), or with 6 mm + pocketing (PIT 3). The subjects were then examined and categorised by one of 32 General Dental Practitioners using the PIT technique upon the six test teeth and subsequently viewing the bitewing radiographs. The results of the two types of examination, with and without bitewing radiographic evidence, were tested for sensitivity and specificity to detect pocketing in excess of 4 mm and/or bone loss. The results showed that, when used without bitewings as an adjunct, the PIT technique showed a specificity of 95-100% but a low sensitivity in three groups (36%, 52% and 59%) and of 94% in the fourth group who had in fact been referred for periodontal treatment. When bitewing radiographs were used as an adjunct to periodontal probing, the PIT technique showed a specificity of 100% in each group and a sensitivity of 89-100% when screening for pockets and/or bone loss. It was concluded that, in the subjects studied, the PIT technique when used in conjunction with bitewing radiography provided simple, rapid and reliable periodontal screening.