Determinants of Bone Dimensional Changes After Extraction and Alveolar Ridge Preservation

The null hypothesis for this study is that there is no difference in bone ridge width and height changes 4 months following extraction and alveolar ridge preservation at sites that undergo immediate post-extraction socket expansion or no immediate post-extraction ridge width change. Patients of the Graduate Periodontics Clinic at Marquette University School of Dentistry scheduled for extraction, bone graft and resorbable membrane will be recruited for this study.

After providing informed consent and prior to local anesthesia and extraction, the following parameters will be recorded: age, gender, race, medical history, medications, tooth site, reason for extraction and tooth mobility. Gingival width will be recorded prior to local anesthesia and extraction, and at 4 months. Gingival thickness will be recorded after local anesthesia and prior to extraction, and at 4 months. Buccolingual ridge width and ridge height will be recorded immediately before, immediately after extraction, and at 4 months. Immediately after extraction, the following measurements will be recorded: buccal bone thickness, number of roots, root length and width, instruments used for extraction, need for flap elevation, duration of extraction, anesthetic amount, type and approach, and operator experience.

• observational study (Other): Observational study; alveolar ridge preservation

Primary outcomes

• Buccolingual ridge width [(1) After local anesthesia and before extraction, (2) immediately after extraction and (3) 4 months after extraction and alveolar ridge preservation]: Buccolingual ridge width will be measured through a stent via ridge mapping calipers. The measurement locations will be at 1mm, 3mm and 5mm from the midbuccal crest. The same measurements will be recorded at all selected time points.
• Ridge height [(1) After local anesthesia and before extraction, (2) immediately after extraction and (3) 4 months after extraction and alveolar ridge preservation]: Ridge height will be measured through a stent via a periodontal probe as the distance between bone and predetermined landmarks on the stent. The measurement locations will be mesial buccal, midbuccal, distal buccal, mesial lingual, midlingual and distal lingual. The same measurements will be recorded at all selected time points.

Sex: All, ages: 18 Years to 75 Years, accepts healthy volunteers

Inclusion Criteria:

* Adult patients (18-75 years)
* Good general health (controlled conditions)
* Controlled periodontal disease
* Scheduled for single tooth extraction with bone graft placement and resorbable membrane
* Tooth to be extracted must have adjacent teeth
* Socket wall integrity

Exclusion Criteria:

* Smoking
* Pregnancy
* Active periodontal disease
* Systemic conditions that affect healing
* Lack of socket wall integrity (bone loss ≥50 %) prior to extraction, teeth with severe infection requiring pre-extraction antibiotic treatment to control infection), and contraindications for tooth extraction.

• Vrisiis Kofina, DDS, MS, Principal investigator, Marquette University