# Allograft Customized Bone Blocks for Ridge Reconstruction: A Case Report and Radiological Analysis
## 11 Discussion  
Autogenous bone is often considered the \"gold standard\" material for bone augmentation procedures, with proven results [18; 19]. However, there are still controversial results regarding the long-term results after grafting with autogenous bone blocks. Significant graft resorption between 20% and 100% of the grafted volume might occur and should be taken into consideration, as shown earlier [20; 21]. In addition, clinical trials comparing autogenous grafts with bone substitutes observed no differences for the clinical outcomes [1]. Tutoplast(r)-processed bone allografts are widely used and have been studied extensively [22; 23; 24; 25; 26]. Up to 127% more vital bone formation has been found after sinus grafting with allograft particulates compared to sinuses that have been grafted with a non-resorbable xenograft material [24; 27]. The amount of residual grafting material after 6 to 7 months of healing time is low, confirming the active remodeling of the allograft material, which seems to be completed after 11 months [28]. Comparing Tutoplast-processed bone allograft to other freeze-dried allografts, it has been shown that, after several months of healing time, the bone formation is higher and amount of residual allograft particulates is lower for Tutoplast-processed bone allografts [29; 30]. The use of allogeneic bone blocks for facial reconstruction was firstly described by [PERSON] in 1950 [31]. Since then, allograft bone blocks have been compared with autogenous bone blocks in a variety of studies. [PERSON] et al. showed comparable bone formations when using Tutoplast(r)-processed allograft blocks compared to autogenous blocks in vertical  
Figure 21: Follow-up at 15 months: clinical view (**a**) and control radiograph (**b**). Figure 20: Bridge delivery (**a**) and control radiograph (**b**). defects in the posterior mandible [32]. Comparable implant survival and success rates of dental implants placed in autogenous block or allograft block-grafted sites have been published [33; 34]. [PERSON] et al. showed a minimal resorption and high-volume stability of 94.3 \(\pm\) 5.45% after allograft block grafting [35]. [PERSON] and coworkers focused on esthetic results after treating patients with autogenous and allograft blocks. Their results showed no differences in the Pink Esthetic Score (PES) between both groups [36]. Moreover, patients assessed the allograft procedure as less painful, since no second site surgery was needed to harvest a block [36]. However, for both types of block grafts, either autogenous blocks or pre-shaped allograft blocks, chairside manipulation is required to fit the block to the defect site, which results in increased surgery time and patient morbidity [37]. Finally, the fit of a manually shaped block graft will never be optimal, which might impact the revascularization and integration of the graft [37]. Customized allograft bone blocks may be beneficial due to their precise fit, which results in a reduced surgery time and risk of complications [3; 4; 34]. The shape of the block allows for a precise outcome in bone height and width, which is more random when using grafting techniques with particulate materials. The large contact surface area of the block improves in the growth of blood vessels and revascularization [37]. Puros\({}^{\circledR}\) Allograft Customized blocks have shown bone remodeling and integration after six months of healing and stable results in different indications and clinical reports [4; 38; 39]. Apart from the fit of the graft, the defect site preparation might have an influence on the integration and vascularization of the block graft. [PERSON] and coworkers showed that cortical perforation of the recipient site did not influence the angiogenesis and new bone formation compared to nonperforated sites [40].