Segmental mandibular bone reconstruction with a carbonate-substituted hydroxyapatite-coated modular endoprosthetic poly(ɛ-caprolactone) scaffold in Macaca fascicularis.

A bio-degradable scaffold incorporating osteoinductive factors is one of the alternative methods for achieving the regeneration of a mandibular bone defect. The current pilot study addressed such a bone reconstruction in a non-human primate model, Macaca fascicularis monkeys, with an engineered poly(ɛ-caprolactone) (PCL) scaffold, provided with a carbonate-substituted hydroxyapatite coating. The scaffolds were implanted into unilaterally created mandibular segmental defects in 24 monkeys.

The use of a polycaprolactone-tricalcium phosphate scaffold for bone regeneration of tooth socket facial wall defects and simultaneous immediate dental implant placement in Macaca fascicularis.

Bone regeneration and aesthetic outcomes may be compromised when immediate implants are placed at extraction sites with dehiscence defects. The aim of this study was to compare, in a monkey model, peri-implant bone regeneration and implant stability after immediate implant placement into tooth sockets with facial wall defects in two treatment groups. In eight control monkeys, the bony defect was reconstructed with autogenous particulate bone, whereas in 10 test monkeys a polycaprolactone-tricalcium phosphate (PCL-TCP) scaffold was used.

Effect of postoperative radiation therapy on mandibular reconstruction using a modular endoprosthesis - a pilot study.

The endoprosthetic system has been shown to be a potential option for mandibular reconstruction. The objective of this pilot in vivo animal study was to determine the effects of postoperative radiation using brachytherapy on bone and soft tissue healing in mandibles reconstructed with the endoprosthesis. Six adult Macaca fascicularis mandibles were reconstructed with a cemented endoprosthesis after segmental body resection.

Subcutaneous tissue response to titanium, poly(ε-caprolactone), and carbonate-substituted hydroxyapatite-coated poly(ε-caprolactone) plates: a rabbit study.

The aim of this study was to evaluate the soft tissue response to poly(ε-caprolactone) (PCL) implants with and without carbonate-substituted hydroxyapatite (CHA) coating compared to the commonly used titanium alloy (Ti-6Al-4V)-machined surface. Experimental materials were implanted subcutaneously in New Zealand white rabbits for 5 weeks. The tissue attachment strength, as evaluated by a tissue peel test, histological and histomorphology analysis, as well as scanning electron microscopy were compared between groups.

The modular endoprosthesis for mandibular body replacement. Part 1: mechanical testing of the reconstruction.

Introduction: In this paper we present the results of the mechanical testing of a new generation modular endoprosthesis, which has been designed to improve the results of mandibular reconstruction.

Materials And Methods: The new cementless endoprosthesis consists of a male part, a female part (both with screws on the stems), connected via a dove-tailed connection and secured with a coronal screw. The endoprosthesis was fitted into standardized blocks of synthetic bone (Synbone AG, Malans, Switzerland).

The modular endoprosthesis for mandibular body replacement. Part 2: finite element analysis of endoprosthesis reconstruction of the mandible.

Introduction: Problems with loosening of the modules for the modular endoprosthesis were encountered in animal studies for mandibular body replacement. We performed a finite element analysis to look at the stress distribution and areas of stress concentration in a human sized mandible. Variations were made to the stem and defect length to look at how the forces changed.

Biocompatibility and bone formation with porous modified PMMA in normal and irradiated mandibular tissue.

Unlabelled: A cemented mandibular endoprosthesis is a potentially viable option for mandibular reconstruction after ablative surgery. The commonly used PMMA cement has the inherent weakness of a lack of bioactivity. Improvement by the addition of porosities and bioactive compounds like calcium phosphates may resolve this issue.

Soft tissue adaptation to modified titanium surfaces.

Surface modification of titanium alloy implants to enhance soft tissue adherence is important to minimize soft tissue dehiscence. This study aimed to confirm if a dual acid etched "Osseotite®" titanium surface contributes to soft tissue adherence in muscle. It also aims to explore if a radio frequency magnetron sputtered hydroxyapatite (HA)/bioglass (BG) coating can serve this purpose and provides soft tissue adherence in mucosal tissue.

Replacement of the condyle and ascending ramus by a modular endoprosthesis in Macaca fascicularis--part 4: evaluation of the temporomandibular joints.

Purpose: To assess, using cone-beam computed tomography and histologic examination, whether the fixation of a condyle-ascending ramus mandibular modular endoprosthesis results in a physiologic condylar replacement in Macaca fascicularis.

Materials And Methods: The right condyle and ascending ramus were resected in 8 adult monkeys and replaced with a modular endoprosthesis, fixed with polymethyl methacrylate bone cement (Palacos). Four monkeys were sacrificed at 3 months and another 4 at 6 months postoperatively.

Replacement of the condyle and ascending ramus by a modular endoprosthesis in Macaca fascicularis--part 3: evaluation of peri-implant bone remodeling.

Purpose: To assess whether the fixation of a condyle-ascending ramus mandibular modular endoprosthesis, using bone cement, will result in stress-related bone resorption in the Macaca fascicularis.

Materials And Methods: The right condyle and ascending ramus were resected in 8 adult monkeys and replaced by a modular endoprosthesis, fixed with polymethylmethacrylate bone cement (Palacos). Four monkeys were sacrificed at 3 months and another 4 at 6 months postoperatively.

Replacement of the condyle and ascending ramus by a modular endoprosthesis in Macaca fascicularis-part 2: microcomputed tomographic and histologic evaluation of the ramus and stem.

Purpose: The present study presents the microcomputed tomographic and histologic evaluation of the peri-implant tissues of a modular endoprosthesis used to replace the condyle and ascending ramus in Macaca fascicularis.

Materials And Methods: The right condyle and ascending ramus were resected in 8 adult monkeys and replaced by a modular endoprosthesis, fixed with polymethylmethacrylate bone cement (Palacos). Four monkeys were sacrificed at 3 months and 4 at 6 months postoperatively.

Bone cements and their potential use in a mandibular endoprosthesis.

Bone cement was first used in the 1950s. Since then many modifications have been made and alternatives developed to the original polymethylmethacrylate (PMMA) cement. In view of the use of bone cement in a novel mandibular endoprosthetic system, we performed a review of the current literature on this material.

Replacement of the condyle and ascending ramus by a modular endoprosthesis in Macaca fascicularis--part 1: a clinical and radiographic study.

Purpose: To evaluate the feasibility of replacing the condyle and ascending ramus with a novel modular endoprosthesis in Macaca fascicularis.

Materials And Methods: Eight male adult monkeys (Macaca fascicularis) were used in this study. The right condyle and ascending ramus posterior to the lower second molar were resected.

Mandibular reconstruction in adults: a review.

Mandibular defects may result from trauma, inflammatory disease and benign or malignant tumours. Mastication, speech and facial aesthetics are often severely compromised without reconstruction. The goal of mandibular reconstruction is to restore facial form and function, implying repair of mandibular continuity and muscle attachments.

Upregulation of GADD153 expression in the apoptotic signaling of N-(4-hydroxyphenyl)retinamide (4HPR).

The molecular basis for the pharmacologic effects of N-(4-hydroxyphenyl)retinamide (4HPR) was investigated by studying the gene(s) that this compound may upregulate in cultured human epithelial tumor cells. Treatment of the cultured human nasopharyngeal carcinoma-derived cells (CNE3) with 4HPR caused modest cell-cycle arrest at G(1) and apoptosis. The mRNA levels of a total of 20 genes were downregulated with the majority of them involved in cell cycle-related functions.