## 3 Results and Discussion
### Prophylaxis  
In recent years, the attempts to evaluate the validity of determining the marker levels of bone turnover in the serum before any surgical intervention in patients treated with anti-resorptive drugs have been made to predict the risk of medication-related osteencrosis in the postoperative period. The indicators that are marked include: s-CTX (C-terminal cross-linked telopeptide of the alpha chain type I collagen), s-OC (osteoclacin), s-PTH (parathormone), and s-BAP (bone isoform of the alkaline phosphatase) [19; 20]. The results of conducted research are pointing to differences in s-CTX, s-OC, s-PTH, and s-BAP levels in patients undergoing anti-resorptive treatment in comparison with the control group [19; 20]. Due to insufficient data from small study groups, there is no hard evidence that would justify a routine marking of those indicators in patients that are at a risk of developing MRONJ [19; 20]. A research of [PERSON] et al. shows that even a 5 month break from intravenous BP therapy is not effective in osteeonecrosis prevention [20]. Other studies show statistically significant differences in the incidence of MRONJ as a result of implementing the so-called \"drug holiday,\" although anti-resorption therapy may not always be discontinued [21]. On the basis of animal studies, [PERSON] et al. demonstrated the validity of local management (bone plasty and wound closure), antibiotic therapy, and the implementation of a break in the use of bisphosphonate (i.e., zoledronic acid) [21]. Patients that belong to the MRONJ risk group are absolutely required to maintain proper oral hygiene as well as systematically visit the dental office for regular hygiization [21, 22]. Dental checkups should be completed every 3 to 4 months [21]. All conservative or endodontic dental procedures should be carried out in accordance with a standard protocol and should not be postponed in order to avoid any surgical intervention [21, 22]. Prosthetic and orthodontic treatment, if properly performed, is classified as low risk for MRONJ occurrence [23]. The implantoprosthetic treatment, on the other hand, has been proven to increase the risk of MRONJ both before and during the anti-resorptive therapy [24]. When a surgical intervention is required in the oral cavity area it ought to be minimally invasive. According to some authors, teeth extractions should be singular and atraumatic, others believe that multiple extractions completed under antibiotic prophylaxis and completed with a tight flap plastic surgery are completely safe [25]. A mucoperiosteal flap should be created when needed and its base should be as wide as possible for maintaining sufficient blood supply [25]. In each case of mucous membrane disruption, the wound requires closure with surgical sutures avoiding tissue overtension [25]. One week prior to the scheduled surgical procedure the patient should implement 0.12% chlorhexidine (CHX) mouth rinsing three times per day and continue with it until the wound is completely healed [25]. The recommendations of the Polish Dental Association and National Programme to Protect Antibiotics Working Group (PDA/NTPAWG) concerning the use of antibiotics in dentistry from 2019 suggest routine antibiotic prophylaxis in patients treated with bisphosphonate, denosumab, or bevacizumabb before all surgical procedures on the jaw bones (teeth extraction, surgery performed on the alveolar process, endodontic or periodontal surgery), which is in line with other guidelines [25, 26, 27]. The antibiotic prophylaxis, according to PDA/NTPAWG protocol, should be implemented one day prior to the procedure and continued for 3 days postsurgery (the so-called short term prophylaxis); in cases of coexisting risk factors for osteonecrosis in the jaw bones, it is advised to prolong the antibiotic therapy up to 14 days (long term prophylaxis) [26]. Detailed risk factors include taking the zoledronic acid orally, bisphosphonates intravenously, using this medication for at least 3 years, and having a history of inflammation or osteonecrosis [26].