Alveolar bone resorption after dental extraction frequently leads to situations in which long-term function and esthetic success of rehabilitations with dental implants is a challenge. "Pontic-shield" has been described as an alternative technique to maintain alveolar ridge after tooth extraction.

The aim of this study is to analyze the effectiveness of "Pontic-shield" technique in alveolar ridge preservation comparing to fresh socket and ridge preservation using deproteinized bovine bone and a porcine collagen membrane.

A three-arm randomized clinical study will be conducted:

• Group 1 (study group): Ridge preservation with "Pontic-shield" technique.
• Group 2 (positive control): Ridge preservation with deproteinized bovine bone and porcine collagen membrane after tooth extraction.
• Group 3 (negative control): Tooth extraction only (fresh socket).

A cone-beam computed tomography will be performed prior to tooth extraction and 4 months postoperative. Radiographic changes between before and after intervention will be evaluated to asses the effectiveness of "Pontic-shield" technique.

Inclusion Criteria:

• Patient from 18 to 80 years old
• Patients who sign the informed consent
• Need to perform extraction from second premolar to second premolar in maxilla and mandible

Exclusion Criteria:

• Tobacco consumption (more than 10 cigarettes per day)
• Severe systemic disease ( ASA III or IV - American Society of Anaesthesiology)
• Drug use that could interfere with alveolar bone healing
• Active periodontal disease
• Acute or chronic apical pathology of the tooth