Teeth with thin root walls exhibit high fracture rate; it is therefore a challenge to fi nd the ideal method to provide them with resistance. To this end, posts, either unfilled or filled with intra-root filling have been used, nevertheless, to this date, no certainty has been established on the differences among these therapeutic options. The main purpose of the present review was to compare evidence results on resistance to fracture of teeth with weakened roots which had been reinforced with either fi lled or unfi lled posts, after being subjected to compressive forces. An electronic search was conducted in different databases (Medline, Embase, PubMed and Ovid). The search was unrestricted with respect to year or language. Aforementioned search produced 148 articles. Each author independently conducted data extraction and quality assessment of each article, following parameters established in calibration (gauging). Finally, seven articles meeting with inclusion criteria were selected. After information collection and analysis, it was concluded that resistance increase in root-weakened teeth was effected when intra-root posts were used, irrespectively of whether these posts had or did not have dentin root reinforcement material.