## 4 Discussion
### BP Use and Dental Implants  
BPs are prescribed in several pathologies, whether they affect the bone (osteoporosis, OI, Paget's disease) or in malignant pathologies (malignant hypercalcemia, bone metastases, lung and breast cancer, and MM), because they prevent bone resorption. Of the studies included in this systematic review, 44 patients had osteoporosis, 8 had MM, 10 had breast cancer, 2 had lung cancer, 1 had prostate cancer, 1 had Langerhans cell histiocrosis, and 1 had OI. The administration of BPs is more prevalent in patients with osteoporosis, since, as reported in the literature, this is one of the most common bone pathologies in developed countries and one which has the most indication for the prescription of these drugs due to the risk of occurrence of bone fractures [29]. Of all the studies included, the presence of patients undergoing therapy with second generation (Alendronate, Pamidronate) [14; 15; 16; 17; 18; 19; 20; 25] and third generation BPs (Risedronate, Zoledronate and Ibandronate) [14; 16; 17; 19; 21; 22; 23; 24; 25] were greater than the use of first generation (Clodronate) [26]. The first generation seems to show a decreasing trend in use nowadays. On the other hand, the failure rate for osseointegration proved to be lower in patients who used therapy with second generation of BPs (about 37%) compared to patients who had therapy with first and third generations. Second generation BPs have been shown to be a well-tolerated drug, with low side effects. This fact has been shown through their growing use in recent years [30]. The interruption of therapy with BPs was a parameter with varied results in this systematic review, from patients who did not discontinue to patients who discontinued for 2, 3, or 6 months before surgery, with respective resumption for 1, 3, or 8 months after surgery. [PERSON] et al. [16] reported the case of two female patients, both in their seventh decade of life, who requested rehabilitation with implant placement. The patients were medicated with second and third generation BPs (Alendronate and Risedronate). After consultation with the attending physician, the patients discontinued BPs 3 months before and resumed 3 months after implant placement. They received antibiotic therapy after surgical interventions, and the treatment plan was completed uneventfully and without complications during a 2-year follow up. In another study, [PERSON] [15] reported the case of a female patient (56 years old), who intended to carry out the prosthetic reconstruction of the crown of two molars lost in the maxilla with the placement of two implants. She was medicated with Alendronate (a second-generation BP) for osteoporosis. There was no bone loss around both implants, and it was observed that the peri-implant soft tissue did not show any signs of inflammation. [PERSON] et al. [21] reported that the placement of dental implants in patients with MM undergoing therapy with third generation BPs (Zoledronate) can be performed. Therefore, a meticulous selection of cases, an adequate medical consultation, and a minimally invasive surgery should be considered. [PERSON] [15], [PERSON] et al. [18], and [PERSON] et al. [20] recommended that patients (n = 13) not interrupt their therapy with BPs during implant placement surgery. [PERSON] [15] and [PERSON] et al. [18] obtained a low failure rate in the implant placement procedure of 0% and 12% respectively. On the contrary, [PERSON] et al. [20] had a complete failure rate (100%). Similarly, in the study carried out by [PERSON] et al. [17], a complete failure of implant placement was observed in patients who started therapy with BPs before implant placement surgery. Otherwise, [PERSON] et al. [21] reported the discontinuation of BP therapy for6 months before surgery that was resumed therapy 8 months after surgery. The failure rate was 0%, and no complications were observed. The same happened with [PERSON] et al. [16] who interrupted therapy 3 months before the surgery and resumed it for 3 months after.