Teeth with thin root walls exhibit high fracture rate; it is therefore achallenge to fi nd the ideal method to provide them with resistance.To this end, posts, either unfilled or filled with intra-root fillinghave been used, nevertheless, to this date, no certainty has beenestablished on the differences among these therapeutic options.The main purpose of the present review was to compare evidenceresults on resistance to fracture of teeth with weakened rootswhich had been reinforced with either fi lled or unfi lled posts, afterbeing subjected to compressive forces. An electronic search wasconducted in different databases (Medline, Embase, PubMed andOvid). The search was unrestricted with respect to year or language.Aforementioned search produced 148 articles. Each authorindependently 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 concludedthat resistance increase in root-weakened teeth was effected whenintra-root posts were used, irrespectively of whether these posts hador did not have dentin root reinforcement material.