This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness 0.2-0.3 mm) was implanted into the mandibular angle of 20 New Zealand White rabbits to cover a through-and-through defect (12!6 mm). In group 1, the defects were left unfilled but covered with membrane and in group 2 the defects were filled with bioactive glass mesh and covered with membrane, too. Controls were left uncovered and unfilled. The animals were followed for 6, 12, 24 and 52 weeks, respectively. The material was evaluated by qualitative analysis of histological reactions and newly formed bone.We found that PDTE carbonate elicited a modest foreign body reaction in the tissues, which was uniform throughout the study. New bone formation was seen in all samples after six weeks. Group 1 had more new bone formation until 24 weeks and after this the difference settled. Based on findings of this study it was concluded that PDTE carbonate membranes have good biocompatibility and are sufficient to enhance bone growth without additional supportive matrix.

Standardized bilateral through-and-through defects (12x6 mm) were created extraorally in the mandibular angle of 18 New Zealand White rabbits. Animals were divided in to three groups (n=6) according to the intended healing time. On the left side, defects were covered with a poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane wrapped around the inferior border of the mandible and fixed with bioabsorbable sutures. On the right side, the defects were filled with a mesh made of bioactive glass 13-93 and 3 wt% chitosan. The defects were covered with the same membranes. Periosteal flap was sutured over the membrane. Radiographically, bone ingrowth was seen in all specimens at 12 weeks postoperatively. At 24 weeks, completely ossified area remained approximately at the same level as at 12 weeks, but the non-ossified area decreased to almost zero. However, the bioactive glass mesh did not improve the results. Nevertheless, enveloping the defect with PDTE carbonate membrane seemed to play a crucial role in new bone formation. Based on these results, we conclude that tyrosine polycarbonate is a promising new material for guided bone regeneration.

The aim of this study was to evaluate rabbit soft tissue reactions to bioactive glass 13-93 mesh by using a histological and immunohistochemical analysis. Bioactive glass (13-93) mesh fixed with 3 wt % chitosan was implanted into the dorsal subcutaneous space of New Zealand White rabbits (n=18) for six, 12, and 24 weeks, respectively. After 6 weeks the bioactive glass remnants were surrounded by foreign-body granuloma with eosinophilic granulocytes. After 12 and 24 weeks the implanted material was mainly absorbed, but, if any particles still remained the foreign-body reaction was notably milder. Yet, a mild chronic inflammatory infiltrate was present. Matrix metalloproteinase (MMP) -2, -3, -13 and tissue inhibitory protein (TIMP-1 and -2) expressions were studied by immunohistochemistry. MMP-3, -13, TIMP-1, and -2 positivity were detected throughout the follow-up period. MMP-2 positivity was only occasionally seen in the 24 week samples, which is constitutively expressed but is not related to inductive MMP-3 and -13 cascade. The presence of eosinophilic granulocytes in some of the samples raises the possibility of an allergic reaction to the materials. MMP-3 and -13 are suggested to participate in the host reaction to either bioactive glass or chitosan.

Different bioabsorbable polymers and their co-polymers have been used to construct an optimal material for guided bone regeneration applications. Our aim was to evaluate a novel bioabsorbable material in a soft tissue environment. In this study, a poly(DTE carbonate) membrane (0.2-0.3 mm) was implanted into 20 NZW rabbits' subcutaneous pouches for 6, 12, 24 and 52 weeks. The material was evaluated by means of histological reactions to the material and mechanical properties of the membrane. Based on this study, it can be concluded that poly(DTE carbonate) elicited a very modest foreign body reaction in the soft tissues. This reaction was uniform throughout the study. Varying amounts of calcification was seen in the fibrous capsule surrounding the implant. The number of calcified bodies did not correlate to healing time.

Background and aim:  During dental education, it would be beneficial for the students to be able to combine theoretical teaching with practical work in a logical manner. For this purpose, a Portfolio software has been developed to facilitate ICT‐based learning with DecaMedia Ltd. Test phase had several aims; test the functionality of the software and add necessary refinements, test the flow of information from teachers to students in different forms and to analyse the possible problems in the use of this software and in ICT‐based learning in general. Material and methods:  A group of teachers and students were gathered to test the usefulness of the new software. Prior to this phase, there had been some testing and a questionnaire study on ICT skills and attitudes. During the first period of this project, the software was customized by DecaMedia to meet our demands. Different access levels were created. The students gathered interesting patient cases and took documents in several media forms. The teachers added theoretical material to combine scientific knowledge with practical work either directly or using links. Results and conclusions:  In general, the following areas were noted: this media is good for supporting assessment . When patient files are added, the importance of privacy protection is high as the files are transferred via network. For theoretical material, the copyright has to be considered as well as the size of network‐delivered documents. This program has a user‐friendly interface. Attachment of different file types was straightforward. The operating language of the program is Finnish, which helps less‐experienced students to get started. There are still some limitations, mainly in stability. We found the program useful to support dental education, but more ICT training will be required for both students and teachers. ICT learning can be beneficial addition in dental education.