Osteoporosis is a skeletal condition characterised by low bone mass and deterioration of the microstructure of bone, most often the spine, ribs, and hips.1 The International Osteoporosis Foundation estimates that osteoporosis affects more than 200 million individuals worldwide.2 The disease process in osteoporosis leads to defective bone formation and consequently weakening in the microstructure of trabecular bone, an increase in cortical porosity, bone fragility and the possibility of fracture. All of these raise concern for dental implant placement which is the topic of the systematic review. The PICO concepts in the review are incorrect. The intervention/exposure in this case is not the implants, but rather having or not having osteoporosis and what will affect the outcome of implant survival.

The review appropriately followed the methodology suggested and adapted the PRISMA statement to conduct the systematic review, searching several databases (four) to look for articles that met their inclusion criteria. Studies included in the search strategy were prospective, retrospective, cohort type/multicentre, case-control, cohort type/prospective and cross-sectional to assess osteoporotic and non-osteoporotic groups. As expected, the search strategy produced observational studies that were accepted for the review, 15 in total, of which six were retrospective cohort studies, five were prospective cohort studies, two were case-control studies and one was a cross-sectional study. A quality assessment was carried out using a level of evidence bias scale proposed by the Australian National Health and Medical Research Council. Most of the included studies were classified as low level of evidence.

The overall results were presented in the narrative section of the published article and were represented in a forest plot figure (meta-analysis).

The results for failure rate at the implant level included ten studies in the meta-analysis, the overall result is not statistically significant p-value: 0.11(RR 1.39, 95% CI 0.93-2.08).

A different meta-analysis was done for the outcome of implant failure at the patient level; the meta-analysis included six studies and the overall results concluded with no statistically significant results (p-value 0.94, RR 0.98, 95% CI 0.50-1.89) and the third forest plot examined marginal peri-implant bone loss and included five studies. This was the only meta-analysis where the results were statistically significant favouring bone loss for the osteoporosis group with a marginal bone loss around implants between patients with and without osteoporosis (0.18 mm, 95% CI 0.05–0.30, P = 0.005).

From the conclusions, it seems that having or not having osteoporosis does not affect dental implant outcome. A modest peri-implant bone loss may be associated.

Another issue to discuss is the use of the outcome survival and failure, the first outcome proposed was survival rate, the results reported and the meta-analysis used failure as the outcome. Survival implies the technique may still be in function; failure is a different complication that implies that the technique was completely unsuccessful.

Overall, the results should be interpreted with caution due to the possible bias of the available evidence.