Regeneration Candidate or Not: An Intrabony Defect Decision
A 45-year-old man, non-smoker, is referred for evaluation of tooth 19. He completed non-surgical therapy 3 months ago. Tooth 19 has a probing depth of 9 mm on the mesial aspect, bleeding on probing, and a radiographic vertical defect on the mesial root with a 4 mm intrabony component and a 2 mm interproximal space. The tooth is vital, has no mobility, and the adjacent tooth 18 is missing. The patient's plaque score is 18% and he brushes twice daily but does not use interdental aids. He asks whether 'bone grafting' can save the tooth. His medical history is unremarkable.
1. Is tooth 19 a candidate for regenerative periodontal surgery? Justify using defect and patient factors.
Read the worked answer
Regeneration is most predictable in a deep, narrow intrabony defect with a contained morphology. Here the defect is 4 mm intrabony with a 2 mm interproximal space, which is narrow and contained, and the tooth is vital with no mobility; these are favorable defect factors. However, the patient's plaque score of 18% with no interdental cleaning is a concern: regenerative outcomes depend on postoperative plaque control, and a patient who does not clean between teeth is at high risk of failure. The 9 mm probing depth and bleeding indicate active inflammation that should be resolved before surgery. The missing adjacent tooth 18 removes one source of interdental plaque but also means the mesial aspect of 19 is now a terminal surface that may be easier to maintain. My judgment: the defect morphology is favorable, but I would not operate until the patient demonstrates improved interdental hygiene and the site is reassessed after further non-surgical therapy. Regeneration is a reasonable option if hygiene improves; otherwise, the risk of failure is high.
2. What would you tell the patient about expected outcomes and alternatives, and what monitoring would you plan?
Read the worked answer
I would explain that regenerative surgery aims to fill the intrabony component and reduce probing depth, but it does not guarantee new attachment and requires strict home care. Realistic expectations include reduced pocket depth and possible radiographic fill, with the need for ongoing maintenance. Alternatives include continued non-surgical maintenance with frequent recall, or extraction and replacement. Because the defect is contained and the tooth is vital and stable, attempting regeneration is defensible if hygiene improves; if the patient cannot maintain interdental cleaning, extraction may be more predictable long term. Monitoring would include probing depths, bleeding on probing, and radiographs at 6 and 12 months, with a 3-month maintenance interval initially. I would also emphasize that smoking cessation is not an issue here, but diabetes and plaque control are the main modifiable risks. The decision should be revisited if bleeding persists or probing depth does not improve.