Feasibility Analysis of Autogenous Tooth-based Bone Graft Material after Guided Bone Regeneration Technique

Abstract Background: We set out to determine the possibility of radiographically evaluating the degree of marginal bone loss in humans after functional loading of implants at sites of guided bone regeneration (GBR) with autogenous tooth-based bone graft (ATBBG) material (AutoB

Evaluation of Early Bone Response to Fluoride-Modified and Anodically Oxidized Titanium Implants Through Continuous Removal Torque Analysis

PURPOSE: To compare between a bioactive and a bioinert implant with different geometries by continuous measurement of the removal torque and calculation of the angular momentum of each surfaced implant.MATERIALS AND METHODS: Six New Zealand white rabbits were used in the study. Each rabbit received 2 implants. A bioactive fluoride-modified implant with a conical connection and microthread design was inserted into one tibia, and a bioinert anodically oxidized implant with an external connection design was inserted into the other. After 2 weeks of implant insertion, the removal torque values were continuously measured according to time. Using the time-torque curve resulting from the measurements, the maximum values were determined, and the angular momenta were calculated.RESULTS: The anodically oxidized implant had significantly higher peak removal torque and angular momentum values than the fluoride-modified implant (P < 0.05).CONCLUSIONS: The impact of the fluoride-modified bioactive implant on early bone response remains unclear. Considering the angular momentum of dental implants may assist in the elucidation of the effect of implant geometry on bone response.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/2008003883/3SEQ:3PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:1.05FILENAME:Implant Dent 201210 21(5) 427-32.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:YCONFIRM:

Identification of a bioactive core sequence from human laminin and its applicability to tissue engineering

Finding bioactive short peptides derived from proteins is a critical step to the advancement of tissue engineering and regenerative medicine, because the former maintains the functions of the latter without immunogenicity in biological systems. Here, we discovered a bioactive core nonapeptide sequence, PPFEGCIWN (residues 2678e2686; Ln2-LG3-P2-DN3), from the human laminin a2 chain, and investigated the role of this peptide in binding to transmembrane proteins to promote intracellular events leading to cell functions. This minimum bioactive sequence had neither secondary nor tertiary structures in a computational structure prediction. Nonetheless, Ln2-LG3-P2-DN3 bound to various cell types as actively as laminin in cell adhesion assays. The in vivo healing tests using rats revealed that Ln2-LG3-P2-DN3 promoted bone formation without any recognizable antigenic activity. Ln2-LG3-P2-DN3-treated titanium (Ti) discs and Ti implant surfaces caused the enhancement of bone cell functions in vitro and induced faster osseointegration in vivo, respectively. These findings established a minimum bioactive sequence within human laminin, and its potential application value for regenerative medicine, especially for bone tissue engineering.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/2008003883/7ADJUST_YN:YEMP_ID:A078517DEPT_CD:861CITE_RATE:8.557FILENAME:044-biomaterials 201512 73() 96-109.pdfDEPT_NM:치의학과SCOPUS_YN:YCONFIRM:

Commentary on an article by Kwon TK, et al.: "First-Order Mathematical Correlation between Damping and Resonance Frequency Evaluating the Bone-Implant Interface"

A recent study on implantology reported a statistical linear correlation between two measures at the bone-implant interface: Periotest evaluation of the damping effect at the interface and resonance frequency analysis. The publication formulated a linear function of the dependent variable, the Periotest value (PTV), to the independent variable, the implant stability quotient value, by homogenizing the density of bone blocks and thoroughly controlling the engaged depth of implants inserted into these blocks. A correlation such as this can be mathematically explained using a second-order differential equation to describe a mechanical vibration model in physics; free vibration with damping. Although several clinical studies have found no significant correlation between the two values, it is important to investigate the reasons for the discrepancy between theory and experimental results in order to understand the nature of the bone around an implant.OAIID:RECH_ACHV_DSTSH_NO:T201700821RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A078517CITE_RATE:0FILENAME:062-038 J Dent Oral Biol 201701 2(2) 1025.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:NFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/7d0e2ff8-390c-4767-9ef2-f626a6ea4e67/linkCONFIRM:

The reliability of an easy measuring method for abutment convergence angle with a computer-aided design (CAD) system

PURPOSE. The purpose of this study was to evaluate the intra-rater reliability and inter-rater reliability of three different methods using a drawing protractor, a digital protractor after tracing, and a CAD system. MATERIALS AND METHODS. Twenty-four artificial abutments that had been prepared by dental students were used in this study. Three dental students measured the convergence angles by each method three times. Bland-Altman plots were applied to examine the overall reliability by comparing the traditional tracing method with a new method using the CAD system. Intraclass Correlation Coefficients (ICC) evaluated intra-rater reliability and inter-rater reliability. RESULTS. All three methods exhibited high intra-rater and inter-rater reliability (ICC>0.80, P<.05). Measurements with the CAD system showed the highest intra-rater reliability. In addition, it showed improved inter-rater reliability compared with the traditional tracing methods. CONCLUSION. Based on the results of this study, the CAD system may be an easy and reliable tool for measuring the abutment convergence angle.OAIID:oai:osos.snu.ac.kr:snu2014-01/102/2008003883/3SEQ:3PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:0FILENAME:j adv prosthodont 201406 6(3) 185-93.pdfDEPT_NM:치의학과SCOPUS_YN:NCONFIRM:

Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

PURPOSE: All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident.MATERIALS AND METHODS: Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also duplicated from the original prepared tooth for fracture testing. A universal testing machine was used to determine the fracture strength of the crowns.RESULTS: THE MEAN FRACTURE STRENGTHS WERE AS FOLLOWS: 54.9 ± 15.6 N for the Lava CAD/CAM zirconia crowns and 87.0 ± 16.0 N for the Digident CAD/CAM zirconia crowns. The difference between the mean fracture strengths of the Lava and Digident crowns was statistically significant (P<.001). Lava CAD/CAM zirconia crowns showed a complete fracture of both the veneering porcelain and the core whereas the Digident CAD/CAM zirconia crowns showed fracture only of the veneering porcelain.CONCLUSION: The fracture strengths of CAD/CAM zirconia crowns differ depending on the compatibility of the core material and the veneering porcelain.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/2008003883/8SEQ:8PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861FILENAME:j adv prosthodont 201305 5(2) 92-7.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:NCONFIRM:

Marginal fit of anterior 3-unit fixed partial zirconia restorations using different CAD/CAM systems

PURPOSE : Few studies have investigated the marginal accuracy of 3-unit zirconia fixed partial dentures (FPDs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) system. The purpose of this study was to compare the marginal fit of zirconia FPDs made using two CAD/CAM systems with that of metalceramic FPDs. MATERIALS AND METHODS : Artificial resin maxillary central and lateral incisors were prepared for 3-unit FPDs and fixed in yellow stone. This model was duplicated to epoxy resin die. On the resin die, 15 three-unit FPDs were fabricated per group (45 in total): Group A, zirconia 3-unit FPDs made with the Everest system; Group B, zirconia 3-unit FPDs made with the Lava system; and Group C, metal-ceramic 3-unit FPDs.They were cemented to resin dies with resin cement. After removal of pontic, each retainer was separated and observed under a microscope (Presize 440C). Marginal gaps of experimental groups were analyzed using oneway ANOVA and Duncan test. RESULTS : Mean marginal gaps of 3-unit FPDs were 60.46 μm for the Everest group, 78.71 μm for the Lava group, and 81.32 μm for the metal-ceramic group. The Everest group demonstrated significantly smaller marginal gap than the Lava and the metal-ceramic groups (P.05). CONCLUSION : The marginal gaps of anterior 3-unit zirconia FPD differed according to CAD/CAM systems, but still fell within clinically acceptable ranges compared with conventional metal-ceramic restoration.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/2008003883/10SEQ:10PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:0FILENAME:첨부된 내역이 없습니다.DEPT_NM:치의학과EMAIL:[email protected]_YN:NCONFIRM:

The effect of the DLTIDDSYWYRI motif of the human laminin α2 chain on implant osseointegration

Considerable effort has been directed towards replacing lost teeth using tissue-engineering methods such as titanium implants. A number of studies have tried to modify bioinert titanium surfaces by coating them with functionally bioactive molecules for faster and stronger osseointegration than pure titanium surfaces. Recently, peptides have been recognized as valuable scientific tools in the field of tissue-engineering. The DLTIDDSYWYRI motif of the human laminin-2 α2 chain has been previously reported to promote the attachment of various cell types; however, the in vivo effects of the DLTIDDSYWYRI motif on new bone formation have not yet been studied. To examine whether a laminin-2-derived peptide can promote osseointegration by accelerating new bone formation in vivo, we applied titanium implants coated with the DLTIDDSYWYRI motif in a rabbit tibia model. The application of the DLTIDDSYWYRI motif-treated implant to tibia wounds enhanced collagen deposition and alkaline phosphatase expression. It significantly promoted implant osseointegration compared with treatment with scrambled peptide-treated implants by increasing the bone-to-implant contact ratio and bone area. These findings support the hypothesis that the DLTIDDSYWYRI motif acts as an effective osseointegration accelerator by enhancing new bone formation.Considerable effort has been directed towards replacing lost teeth using tissue-engineering methods such as titanium implants. A number of studies have tried to modify bioinert titanium surfaces by coating them with functionally bioactive molecules for faster and stronger osseointegration than pure titanium surfaces. Recently, peptides have been recognized as valuable scientific tools in the field of tissue-engineering. The DLTIDDSYWYRI motif of the human laminin-2 α2 chain has been previously reported to promote the attachment of various cell types; however, the in vivo effects of the DLTIDDSYWYRI motif on new bone formation have not yet been studied. To examine whether a laminin-2-derived peptide can promote osseointegration by accelerating new bone formation in vivo, we applied titanium implants coated with the DLTIDDSYWYRI motif in a rabbit tibia model. The application of the DLTIDDSYWYRI motif-treated implant to tibia wounds enhanced collagen deposition and alkaline phosphatase expression. It significantly promoted implant osseointegration compared with treatment with scrambled peptide-treated implants by increasing the bone-to-implant contact ratio and bone area. These findings support the hypothesis that the DLTIDDSYWYRI motif acts as an effective osseointegration accelerator by enhancing new bone formation.Tissue-engineeringThis work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by MEST (Grant No. 2011-0007662) and the Mid-career Researcher Program through NRF, funded by MEST (Grant No. 2010-0014662).OAIID:oai:osos.snu.ac.kr:snu2013-01/102/2008003883/1SEQ:1PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:7.404FILENAME:Biomaterials 201305 34(16) 4027-37.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:YCONFIRM:

Discovery of Q203, a potent clinical candidate for the treatment of tuberculosis

New therapeutic strategies are needed to combat the tuberculosis pandemic and the spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) forms of the disease, which remain a serious public health challenge worldwide1, 2. The most urgent clinical need is to discover potent agents capable of reducing the duration of MDR and XDR tuberculosis therapy with a success rate comparable to that of current therapies for drug-susceptible tuberculosis. The last decade has seen the discovery of new agent classes for the management of tuberculosis3, 4, 5, several of which are currently in clinical trials6, 7, 8. However, given the high attrition rate of drug candidates during clinical development and the emergence of drug resistance, the discovery of additional clinical candidates is clearly needed. Here, we report on a promising class of imidazopyridine amide (IPA) compounds that block Mycobacterium tuberculosis growth by targeting the respiratory cytochrome bc1 complex. The optimized IPA compound Q203 inhibited the growth of MDR and XDR M. tuberculosis clinical isolates in culture broth medium in the low nanomolar range and was efficacious in a mouse model of tuberculosis at a dose less than 1 mg per kg body weight, which highlights the potency of this compound. In addition, Q203 displays pharmacokinetic and safety profiles compatible with once-daily dosing. Together, our data indicate that Q203 is a promising new clinical candidate for the treatment of tuberculosis