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Tricalcium phosphate (TCP) bioceramics, available as α- and β-polymorphs, are frequently employed in the production of three-dimensionally (3D) printed bone scaffolds. Although hydrothermal immersion processing (HP) and sintering (S) are commonly adopted as post-printing techniques for bioceramics, a comprehensive comparative analysis of their effects on the osteogenic performance of α- and β-polymorphs in vivo remains inadequately investigated. In this study, α-TCP and β-TCP scaffolds were fabricated via direct ink writing and subjected to hydrothermal immersion processing (α-TCP/HP) and sintering (β-TCP/S) prior to implantation in n = 12 skeletally mature sheep (n = 1 scaffold per group per animal), and the outcome variables were evaluated at 3 and 12 weeks postoperatively (n = 6 sheep per time point). The quantitative results showed no significant differences in bone deposition or scaffold resorption at 3 weeks postoperatively (p = 0.618 and p = 0.898, respectively). However, at 12 weeks, there was a significant increase in osteogenesis and scaffold resorption in the β-TCP/S cohort relative to the α-TCP/HP counterparts (p < 0.001 and p = 0.004, respectively). β-TCP scaffolds subjected to post-print sintering exhibited superior osteoconductive and resorptive profiles compared to hydrothermal immersion-processed α-TCP scaffolds over the 12-week healing period.

Peri-implant disease and gingival recession may be partially attributed to inadequate keratinized tissue. Soft tissue augmentation procedures utilizing non-autologous biomaterials, such as porcine-derived collagen membranes, have been gaining prominence and exogenous crosslinking is being actively investigated to improve the collagen membrane’s stability and potential for keratinized tissue gain. The aim of this preclinical study was to evaluate the performance of a novel, crosslinked porcine collagen membrane (ZdermTM, Osteogenics Biomedical, Lubbock, TX, USA) relative to an established, commercially available, non-crosslinked counterpart (Mucograft®, Geistlich Pharma North America Inc., Princeton, NJ, USA) in a canine mandibular model. Bilateral split-thickness mucosal defects were created in adult beagles (n = 17), with each site receiving one membrane. Qualitative and quantitative histomorphometric analyses of groups were performed after 4, 8, and 12 weeks of healing and compared to unoperated, positive controls from the same subject. No significant differences in membrane presence were observed between ZdermTM and Mucograft® at 4, 8, and 12 weeks of permitted healing (p > 0.05). Similarly, the average keratinized tissue (KT) length between ZdermTM and Mucograft® groups was statistically equivalent across all healing times (p > 0.05). However, qualitative histological evaluation revealed greater rete ridge morphology amongst defects treated with ZdermTM in comparison to Mucograft®. Nevertheless, both membranes exhibited excellent biocompatibility and are well-suited for soft tissue augmentation procedures in the oral cavity.

Achieving the appropriate primary stability for immediate or early loading in areas with low-density bone, such as the posterior maxilla, is challenging. A three-dimensional (3D) stabilization implant design featuring a tapered body with continuous cutting flutes along the length of the external thread form, with a combination of curved and linear geometric surfaces on the thread’s crest, has the capacity to enhance early biomechanical and osseointegration outcomes compared to implants with traditional buttressed thread profiles. Commercially available implants with a buttress thread design (TP), and an experimental implant that incorporated the 3D stabilization trimmed-thread design (TP 3DS) were used in this study. Six osteotomies were surgically created in the ilium of adult sheep (N = 14). Osteotomy sites were randomized to receive either the TP or TP 3DS implant to reduce site bias. Subjects were allowed to heal for either 3 or 12 weeks (N = 7 sheep/time point), after which samples were collected en bloc (including the implants and surrounding bone) and implants were either subjected to bench-top biomechanical testing (e.g., lateral loading), histological/histomorphometric analysis, or nanoindentation testing. Both implant designs yielded high insertion torque (ITV ≥ 30 N⋅cm) and implant stability quotient (ISQ ≥ 70) values, indicative of high primary stability. Qualitative histomorphological analysis revealed that the TP 3DS group exhibited a continuous bone–implant interface along the threaded region, in contrast to the TP group at the early, 3-week, healing time point. Furthermore, TP 3DS’s cutting flutes along the entire length of the implant permitted the distribution of autologous bone chips within the healing chambers. Histological evaluation at 12 weeks revealed an increase in woven bone containing a greater presence of lacunae within the healing chambers in both groups, consistent with an intramembranous-like healing pattern and absence of bone dieback. The TP 3DS macrogeometry yielded a ~66% increase in average lateral load during pushout testing at baseline (T = 0 weeks, p = 0.036) and significantly higher bone-to-implant contact (BIC) values at 3 weeks post-implantation (p = 0.006), relative to the traditional TP implant. In a low-density (Type IV) bone model, the TP 3DS implant demonstrated improved performance compared to the conventional TP, as evidenced by an increase in baseline lateral loading capacity and increased BIC during the early stages of osseointegration. These findings indicate that the modified implant configuration of the TP 3DS facilitates more favorable biomechanical integration and may promote more rapid and stable bone anchorage under compromised bone quality conditions. Therefore, such improvements could have important clinical implications for the success and longevity of dental implants placed in regions with low bone density.

Alveolar ridge preservation by guided bone regeneration (GBR) is a surgical procedure that can be performed prior to implant placement to increase the likelihood of survival. Autogenic, allogenic, or xenogeneic derived bone (particulate graft) are frequently placed in conjunction with a barrier membrane for GBR; however, advancements in tissue engineering have led to the development of promising synthetic alternatives. Fiber-based scaffolds exhibit high surface-to-volume ratio and thereby improve cellular adhesion, reduce the likelihood of dehiscence and poor bone regeneration often associated with poorly immobilized particulate graft. This study aimed to evaluate the performance of a novel electrospun composite scaffold coated in a recombinant variant of human bone morphogenetic protein-2 (OsteoAdapt) relative to a porcine-derived xenograft. Further, it sought to determine if OsteoAdapt would remain within the defect without a membrane in place, as this is not feasible with the particulate xenograft currently used in clinical practice. Four-walled mandibular defects were created in each adult beagle dog (n = 4 defects per dog; n = 4 dogs for a total of 16 defects). Each defect received one of three experimental (test) groups: (i) OsteoAdapt without membrane (OA), (ii) OsteoAdapt with porcine membrane (OA/ZM), (iii) OsteoAdapt mixed with porcine particulate xenograft (Zcore™) with porcine membrane (OA/P/ZM) and compared to a positive control - Zcore™ with porcine membrane (CTRL). After 4-weeks , bone regeneration was assessed through qualitative volumetric reconstruction, qualitative and quantitative histological analyses. Histomorphometric measurement of bone regeneration (% bone) within the region of interest revealed no significant differences between OA, OA/ZM, or OA/P/ZM in comparison to the CTRL at 4-weeks ( = 0.086, = 0.218, and = 0.806, respectively). Similarly, evaluation of soft tissue presence (% soft tissue) indicated no significant differences between experimental groups OA, OA/ZM, or OA/P/ZM relative to the CTRL ( = 0.341, = 0.679, = 0.982, respectively). However, qualitative analysis of the histological micrographs demonstrated advanced bone healing characterized by an abundance of nucleation sites for regeneration to occur in defects treated with OA relative to the CTRL. Bone overgrowth beyond the limits of defect borders was observed in groups treated OA/ZM and OA/P/ZM. In contrast to the treatment groups, minimal woven bone was visualized in the CTRL group. Compared to defects treated with porcine-derived particulate and barrier membrane (CTRL), defects filled with OA exhibited bone regeneration throughout the defect, with bone overgrowth when covered by a barrier membrane at 4-weeks . This suggests that the novel combination of AMP-2 and a bioceramic/synthetic polymer-based electrospun scaffold is a suitable candidate for GBR procedures, without a barrier membrane to secure its place within a defect.