# Allogeneicic Demineralized Dentin Matrix Graft for Guided Bone Regeneration in Dental Implants
## 2 Materials and Methods
### Transplantation of DDM and Implant Placement  
Surgical procedures (extraction, implantation, and GBR) were performed by a single surgeon. Immediately after extraction, the implant (diameter: 3.8 mm, length: 10, 11.5, and 13 mm; Dio, Busan, Korea) was placed with simultaneous GBR using the DDM (Auto-DDM or Allo-DDM).  
Under local anesthesia using 2% lidocaine HCl with 1:100,000 epinephrine (Lidocaine HCl; Huons, Seongnam, Korea), crestal and mesio-distal vertical incisions were made with a No. 15 blade (Braun Manufacturing, Frankfurt, Germany). Following mucoperiosteal flap elevation, tooth extraction was performed. For the atraumatic extraction, the surgeon did not perform osteotomy on the remaining bone around the tooth. Copious removal of granulation tissues was performed by molt curettage, and profuse saline irrigation was performed. The remaining buccal marginal bone was trimmed to at least 0.5 mm thickness or more by 2.0 mm round burr without damaging the mucoperiosteal flap. Dental implants were placed to achieve primary stability with sufficient alveolar bone width (Figure 1a). The DDM was applied to the GBR to repair the damaged buccal alveolar wall (Figure 1b). Primary closure of the surgical sites was achieved with simple interrupted sutures using 4-0 vicryl sutures (Ethicon, Somerville, NJ, USA) after releasing incisions and coronally repositioned flaps. Barrier membranes were not applied because the collagen portion of the DDM was sufficient to bind to the patient's blood (Figure 1c). Patients were instructed to rinse their mouth twice daily with a 0.1% chlorhexidine solution and take oral antibiotics (625 mg, amoxicillin, Ilsung Pharmaceutical, Daejeon, Korea) twice daily for three days [24]. After three to six months, satisfactory clinical healing was observed in all patients without any sign of infection or graft failure, and the surgical site was re-opened for prosthetic loading. Implants were loaded with screw-retained provisional restorations. Further, a bone sample was harvested from the area overlying the implant cover screw using a surgical scalpel (Dentium, Seoul, Korea) from one patient who consented to undergo a biopsy (Figure 1d). The specimen was demineralized with 10% formic acid after fixation in 10% neutral-buffered formalin. Paraffin sections (thickness 5 \(\upmu\)m) were stained with hematoxylin and eosin (HE) for histological observation.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \begin{tabular}{c} **Age** \\ **(Years, SD)** \\ \end{tabular} & \(p\)**-Value** & \multicolumn{4}{c}{**Buccal Bone Height (mm, SD)**} \\ \cline{3-6}  & \
\begin{tabular}{c} **Age** \\ **(Years, SD)** \\ \end{tabular} & \(p\)**-Value** & \multicolumn{2}{c}{**T1**} & \multicolumn{2}{c}{**T2**} & \multicolumn{2}{c}{**T3**} & \(p\)**-Value** \\ \hline Total (n = 96) & 57.13 (8.11) & & 10.78 & 10.15 & 9.80 & \(<\)0.001 * \\ Sex & & & (1.84) & (1.82) & (1.64) & (Between each stage) \\ Male (n = 59) & 56.13 (6.97) & 0.117 \(\uptau\) & 11.31 & 10.66 & 10.22 & T1: 0.397 \(\uptau\) \\ Female (n = 37) & 58.73 (9.00) & & 11.09 & 10.45 & 9.91 & T2: 0.788 \(\uptau\) \\ Location & & & (1.81) & (1.86) & (1.80) & T3: 0.576 \(\uptau\) \\ Maxilla (n = 54) & 57.72 (6.97) & 0.410 \(\uptau\) & 11.46 & 10.68 & 10.14 & T1: 0.136 \(\uptau\) \\ Mandible (n = 42) & 56.38 (8.93) & & 10.92 & 10.44 & 10.15 & T2: 0.531 \(\uptau\) \\ Types of DDM & & & (1.76) & (1.60) & (1.54) & T3: 0.804 \(\uptau\) \\ Auto-DDM (n = 44) & 56.45 (7.61) & 0.436 \(\uptau\) & 11.76 & 11.09 & 10.45 & T1: 0.004 \(\uptau\) \\  & & 0.436 \(\uptau\) & (1.84) & (1.70) & (1.77) & T2: 0.011 \(\uptau\) \\ Allo-DDM (n = 52) & 57.71 (8.11) & & 10.78 & 10.45 & 9.80 & T3: 0.065 \(\uptau\) \\  & & (1.45) & (1.82) & (1.64) & & \\ \hline \hline \end{tabular}
\begin{tabular}{c} BMB; buccal marginal bone. * Paired \(t\)-test. + Independent-sample \(t\)-test. \\ \end{tabular}
\end{table}
Table 1: Demographic information of patients and buccal marginal bone (BMB) height at surgery (T1), at prosthetic loading (T2), and 12 months after loading (T3).