O46 SUTURABLE MESH IMPROVES OUTCOMES FOR LAPAROTOMY CLOSURE IN COMPARISON TO POLYPROPYLENE SUTURE IN A REALISTIC PORCINE MODEL

Aim Laparotomy closures fail due to suture pull-through. We hypothesize that a novel suturable mesh device may limit pull-through via mechanisms of force distribution at the suture-tissue interface and fibrous encapsulation of the device filaments. This new tissue approximation device may lead to improved outcomes for laparotomy closure. Material and Methods Fifteen domestic swine 74 kg in size were randomly allocated to three groups for epigastric laparotomy closure with either size 0 suturable mesh, number 1 suturable mesh, or number 1 polypropylene. All three devices were placed in running fashion with 1 cm bites and 1 cm travels. Primary endpoints were hernia formation at 13 weeks and a semiquantitative analysis of the histological tissue response. Secondary endpoints included adhesions, surgical site occurrence (SSO), and documentation of “loose sutures”. Results There were numerically fewer hernias in the number 1 suturable mesh group. Nine of the 10 suturable mesh devices were well encapsulated within the tissues and could not be pulled away, while 4 of the 5 polypropylene sutures were loose. Adhesions were least for number 1 suturable mesh. Histologically, the suturable mesh implanted devices showed good fibrovascular ingrowth and were judged to be “non-irritants”. The soft tissue response was statistically greater (p = .006) for the number 1 suturable mesh than for the number 1 polypropylene. Conclusions The mechanism of how meshes support closure sites is clearly demonstrated with this model. Suturable mesh has the potential to change surgical algorithms for abdominal wall closure.

Parametrizing the genioplasty: a biomechanical virtual study on soft tissue behavior

Purpose Sliding genioplasty is used to surgically correct a retruded or misaligned chin: in this procedure, an osteotomy is performed and the bony segment is repositioned. In this study we investigate the effect of surgical parameters (bony segment movement, osteotomy design) on postop soft tissue changes in a patient cohort. Methods Seven patients were retrospectively recruited. Cone beam computed tomography data were obtained and soft tissue and bone shape reconstructions were performed. 3D models were created and surgical cuts were replicated according to postop scans. Each model was imported in ANSYS 2019R1 (Ansys Inc, USA) for simulation: the effect of variation in osteotomy plane as well as extent of bony segment movement were assessed by means of design of experiment: surgical parameters were varied in a surgically acceptable range and the soft tissue predictions were evaluated as displacement output of five craniometric landmarks. Results Simulation results show the overall changes of the lower third of the face are sensitive to changes in horizontal and vertical displacement of the bony segment as well as segment rotation. No significant changes in the soft tissue response were to attribute to the osteotomy design. Conclusions Our results are consistent with experimental findings reported in the literature: when planning genioplasty in orthognathic surgery, particular focus on the segment movement (horizontal translation, vertical translation and rotation), rather than on the design of the osteotomy itself, should be considered.

Early soft tissue response to zirconium oxide and titanium healing abutments in vivo: a study in dogs

Background This study aimed to investigate the clinical characteristics and early soft tissue response to zirconium oxide (Zr) and titanium (Ti) healing abutments in dogs. Methods Eight implants (four at each hemi-mandible) were inserted after bilateral mandibular third and fourth premolars and first molar extraction in dogs. Then, two Zr and two Ti healing abutments were connected to each unilateral mandible eight weeks later. The ligation method was used to create a peri-implant mucositis model and the 24 abutments were divided into four groups: Zr or Ti healing abutments with ligation (ZrL, TiL) or non-ligation (ZrN, TiN). The clinical indices, peri-implant crevicular fluid (PICF), and inflammatory cytokines (TNF-α and IL-1β) were measured and analyzed on days 0 and 28. The dogs were then sacrificed on day 28, soft tissues around the implants were harvested, and inflammation infiltration was tested by immunohistochemistry. Normal distribution test and two-way analysis of variance was used to analyze the data. Results The results showed that the clinical indices were similar for Zr and Ti healing abutments. There was significantly more PICF in the ZrL and TiL groups compared to in the ZrN and TiN groups. The TNF-α levels in PICF were significantly different between ZrL and ZrN groups on day 28. And the TNF-α levels in PICF were significantly higher in TiL group on day 28 than that on day 0. However, the number of inflammatory cells was not significantly different between the groups as measured by immunohistochemistry. Conclusions These data indicate that soft tissue responses to Zr healing abutments with peri-implant mucositis were comparable to those of Ti healing abutments in vivo, providing a theoretical foundation for the clinical application of Zr abutments.

Will Zirconia Implants Replace Titanium Implants?

This review aims to discuss the advantages and disadvantages of zirconia implants compared with titanium implants. Moreover, it intends to review the relevant available long-term literature of these two materials regarding osteointegration, soft-tissue, microbiota, and peri-implantitis, focusing on clinical results. Briefly, titanium implants are a reliable alternative for missing teeth; however, they are not incapable of failure. In an attempt to provide an alternative implant material, implants made from ceramic-derivate products were developed. Owing to its optimal osseointegration competence, biocompatibility, and esthetic proprieties, zirconium dioxide (ZrO2), also known as zirconia, has gained popularity among researchers and clinicians, being a metal-free alternative for titanium implants with its main use in the anterior esthetic zones. This type of implant may present similar osseointegration as those noted on titanium implants with a greater soft-tissue response. Furthermore, this material does not show corrosion as its titanium analog, and it is less susceptible to bacterial adhesion. Lastly, even presenting a similar inflammatory response to titanium, zirconia implants offer less biofilm formation, suggesting less susceptibility to peri-implantitis. However, it is a relatively new material that has been commercially available for a decade; consequently, the literature still lacks studies with long follow-up periods.