## 3 Results  
During the study period, twenty patients completed the protocol. Six patients were in treatment with BPs for cancer skeletal-related events (ONC group), the other fourteen patients (70%) were in treatment for metabolic bone disease (OST group) (Table 3). Three patients (15%) received concomitant systemic corticosteroid therapy, all belonging to the ONC group. Only four patients (20%) were no longer in treatment with BPs at the moment of the surgical procedure, all belonging to the ONC group (7 \(\pm\) 6.5 months). In the OST group, the period of assumption of BPs was of \(74.5\pm 34.73\) months, most of the patients were in treatment with alendronic acid per os (42.86%) and clodronic acid by IM (28.57%). Sixty-three tooth extractions were made (Figure 1a): thirty-three extractions (52.38%) were from the maxilla (eight anterior teeth, 25 posterior teeth) and thirty (47.62%) from the mandible (nine anterior teeth, 21 posterior teeth). Twenty-four teeth were extracted in the ONC group (four teeth/patient), while thirty-nine teeth were extracted in the OST group (2.7 teeth/patient) (Table 4). Figure 1: Surgical technical procedures in one cancer (ONC) patient taking intravenous bisphosphonates. (**A**) Pre-operative view of the two compromised teeth. (**B**) Intra-operative view after teeth extraction, bone curettage and osteoplastic procedures. (**C**) Packed platelet rich-plasma (PRP). (**D**) Sutures. In detail, in the ONC group the duration of BPs therapy was of \(34.17\pm 19.97\) months; all patients were in treatment with zoeldronic acid by IV, according to the standard regimen. Dental extraction was indicated for thirty-five teeth due to Miller degree 3 mobility (14 and 21 in the ONC and OST groups, respectively). Eighteen teeth were extracted because of large carious lesions that could not be treated conservatively (six and 12 in the ONC and OST groups, respectively). The remaining ten teeth (four and six in the ONC and OST groups, respectively) were extracted for other reasons (e.g., vertical root fracture, endodontic treatment failure). In 24 of 63 extraction sockets (38.09%), the healing of the oral mucosa was completed at the removal of sutures; the presence of granulation tissue was recorded in the other 39 of 63 extraction sockets (61.9%), but, at the following visit at one month, a stable healed mucosa was recorded. In a 62-year-old woman affected by breast cancer, and in treatment with zoeldronic acid for 72 months, a small area of bone exposure was detected after fifteen days, but it was resolved completely by the subsequent visit at one month, and never showed signs of ONJ in the follow up period. At the 12-month follow-up visit, all patients (100%) showed no clinical or radiological sign of BRONJ. At the most recent follow-up visit, all patients had intact mucosa and no clinical or radiological signs of ONJ (as example see Figures 1 and 2). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{2}{c}{**N Extraction (\%)**} & \multicolumn{1}{c}{**Maxilla/Mandible**} & \multicolumn{1}{c}{**Site**} & \multicolumn{1}{c}{\(N\) (\%)**} \\ \hline \multirow{4}{*}{**ONC group**} & \multirow{2}{*}{\
\begin{tabular}{c} 24 \\ (38.09\%) \\ \end{tabular} } & \multirow{2}{*}{Maxilla} & Anterior & 3 (4.8\%) \\ \cline{3-5}  & & & Posterior & 10 (15.9) \\ \cline{3-5}  & & & & Anterior & 2 (3.2\%) \\ \cline{3-5}  & & & Posterior & 9 (14.3\%) \\ \hline \multirow{4}{*}{**OST group**} & \multirow{2}{*}{
\begin{tabular}{c} 39 \\ (61.9\%) \\ \end{tabular} } & \multirow{2}{*}{Maxilla} & Anterior & 5 (7.9\%) \\ \cline{3-5}  & & & Posterior & 15 (23.8\%) \\ \cline{3-5}  & & & Anterior & 7 (11.1\%) \\ \cline{3-5}  & & & Posterior & 12 (19\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Descriptive details of the extracted teeth (total N=63).