Aim: To evaluate the international scientific literature that refers to techniques, clinical results, and bone healing process of alveolar ridge preservation procedures when using xenografts and allografts and those allowing alveolar healing process. Methods: This literature review was performed using the scientific search engines Medline/PubMed, Wiley Online Library, OVID, EBSCO, ScienceDirect and Nature.com. Articles in English, Spanish and Italian published in journals indexed in scientific databases available online were included. The search was carried out with the MeSH term alveolar ridge preservation. The search was not restricted by publication date. All the full-text articles available on line were included. Results: 99 journal articles were found. It is evident that less vertical and horizontal bone loss occurs on preserved alveolar ridges than on non-treated sites. On-site treatments with allografts show a results ranging from 1.3 mm vertical bone gain to 1.8 mm vertical bone loss. On-site treatments with xenografts showed a range of response such as 0.7 mm vertical bone gain and 1.0 mm vertical bone loss. It was found that the use of allografts showed a horizontal bone loss of 0.5-1.8 mm while responses to xenografts were 0.5-2.1 mm. Conclusions: A statistical analysis of the evidence was not possible to carry out due to differences in inclusion criteria among the studies. Despite the clinical and histological differences were not significant, the evidence analyzed reports better results of alveolar ridge preservation using xenografts.