Patients were asked to keep their oral hygiene daily dairy. On follow up appointments all the patients had periodontal pockets measured and they were also asked about any problems after ozone treatment. The questions were about the status of the gingiva (bleeding or any discomfort) in the following days after the treatment with ozone. This was in a form of verbal questionnaire during the follow up appointment. On the three months follow up appointment BPE scores were also measured. Treatment with ozone was not repeated on follow up appointments. All the measurements, treatment and follow up appointments were carried out by one of the authors.