Efficacy of Socket Grafting for Alveolar Ridge Preservation

The purpose of this study is to clinically and radiographically assess whether the use of a ridge preservation technique significantly minimizes alveolar ridge resorption following tooth extraction.

Subjects requiring single-rooted tooth extractions and future tooth replacement therapy with implant-supported restorations will be recruited. Subjects will be randomly assigned to either a control (tooth extraction alone) or an experimental group (tooth extraction and ridge preservation using an allograft to fill the alveolar socket covered with a non-absorbable, dense polytetrafluoroethylene membrane \[dPTFE\]). Clinical linear measurements of the ridge (horizontal and vertical) will be obtained using a tooth-supported stent. Following extraction, primary closure of the socket will not be attempted. Subjects will be re-evaluated at 1 and 4 weeks. Implant placement surgery will be performed at 16 weeks. Clinical measurements will be repeated upon surgical re-entry. Cone beam computed tomographic (CBCT) scans will be obtained at baseline (after tooth extraction) and at 14 weeks (prior to implant placement) to assess alveolar ridge volumetric changes (primary outcome). Secondary outcome measures include changes in bucco-lingual and apico-coronal clinical measurements of the ridge and changes in modified wound healing index changes overtime. The influence of the thickness of the facial and lingual bone of the alveolar ridge and the width of the keratinized tissue on the remodeling of the ridge will be evaluated.

Eligibility Criteria:
Inclusion Criteria:

* Age: 18 to 75 years.
* Gender: No restriction.
* Subjects must require a single-rooted tooth extraction (Tooth deemed as periodontally and/or restoratively hopeless), except lower incisors and second premolars.
* Subjects must be able and willing to follow instructions related to the study procedures.
* Subjects must have read, understood and signed an informed consent form.

Exclusion Criteria:

* Reported allergy or hypersensitivity to any of the products to be used in the study.
* Severe hematologic disorders, such as hemophilia or leukemia.
* Active severe infectious diseases that may compromise normal healing.
* Liver or kidney dysfunction/failure.
* Currently under cancer treatment or within 18 months from completion of radio- or chemotherapy.
* Subjects who have a long-term history of oral bisphosphonate use (i.e. 10 years or more).
* Subjects with a history of IV bisphosphonates.
* Subjects with uncontrolled diabetes.
* Subjects with severe metabolic bone diseases, such as Paget's disease of bone, will be excluded.
* Pregnant women or nursing mothers.
* Smokers: Subjects who have smoked within 6 months of study onset.
* Concomitant medications: Subjects on concomitant drug therapy for systemic conditions that may affect the outcomes of the study will not be included in the study.

NOTE: Occasional, short-term use (7-14 days) of analgesics or common cold medications is permitted. Use of such medications will be reviewed and recorded by the investigator.

- Any other non-specified reason that from the point of views of the investigators will make a candidate not a suitable subject for the study (e.g. limited mouth opening).