• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.529-540
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• 1994

Rapidly progressive periodontitis is known to be usually associated with systemic problems and improved with antibiotic therapy. Recent experiments in which bioresorbable polycaprolactone was polymerized with minocycline has shown that the system released effective antibiotic concentration during the 7 days' period. This clinical trial was to compare the efficacy of a minocycline film(poly-caprolactone+polyglycol+10% minocycline) insertion plus supragingival scaling(MS) or subgingival scaling & root planing(MSRP) with the scaling(S) or subgingival scaling & root planing alone(SRP), at improving the periodontal condition in RPP. Fifteen patients were examined for plaque accumulation, gingival inflammation, probing depth and attachment loss at baseline, then 1, 2, 4 and 8 weeks after 4 treatment regimens were randomly undergone in 4 comparable sites(PD>5mm, LA>3mm) in each subject. Results revealed statistically significant treatement effect with a reduction in a probing depth in SRP(2.0mm), MS(1.8mm), and MSRP(2.1mm). There was no significant reduction in the supragingival scaling alone group(0.6mm). Similarly, attachment levels were significantly improved in the SRP(1.5mm), MS(2.0mm) and MSRP(2.0mm) groups. Net % BOP reduction at 8 week compared to baseline was 6.7% (S), 26.7% (MS), 26.7% (SRP), and 33.3% (MSRP). MSRP produced the greatest improvement in BOP at 8 week. This data suggests that a subgingival minocycline delivery system as a adjunct to scaling alone or scaling & root planing may produce significant clinical benefits over scaling alone in rapidly progressive periodontitis patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.438-443
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• 2003

Purpose : This study evaluated the usefulness of resorbable plate and screw for treatment of maxillofacial bone fractures. Patients and methods : From july, 2000 to july, 2002, we used resorbable plates and screws($Biosorb^{(R)}$ FX, Bionix Inc, Finland) on 126 patients for treatment of maxillofacial bone fractures. Among them, 80 patients were capable of periodic following up to present season. We evaluated these patients with clinical, radiographic findings and subjective satisfaction. Results : 80 patients composed of 63 men and 17 women. Complication rates are 7.5%(6/80) recorded. 1 of bulging sensation, 3 of infection sign, 2 of the plate detachment were shown. The plates involved in such complications were removed. The other patients(92.5%) were not shown any problems. We could not find complete resorption of screw holes in the mandibular symphysis area even though two years later after surgery. Conclusion : Bioresorbable plates and screws are useful as fixation material at maxillofacial fractures although strength is thought to be weaker than titanium plate. But to reduce the possible complicaions, need to careful clinical and radiographical evaluations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.499-503
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• 2007

Introduction: In orthognathic surgery, internal fixation has been usually done with titanium plates and screws. Recently, Biodegradable plates and screws have been frequently used but the reports of long term results of postoperative stability are rare, especially after maxillary reposition in orthognathic surgery. Objective: In order to clarify the clinical utility of self-reinforced bioresorbable poly-70L/30DL-Lactide miniplates & screws in maxillary fixation after LeFort I osteotomy, this study examined the postsurgical changes in maxilla and complications of biodegradable plates and screws. Study design: Nineteen patients who had undergone maxillary internal fixation using biodegradable plates and screws were evaluated radiographically and clinically. A comparison study of the changes in maxilla position after surgery in all 19 patients was performed with 1-week, 1-month, 3-months, 6-months and/or 1-year postoperative lateral cephalograms by tracing. Complication of the biodegradable plates and screws was evaluated by follow-up roentgenograms and clinical observation. And one-way ANOVA test was used for statistical analysis. Results: The position of the maxillary bone was stable after surgery and was not changed significantly from 1 week to 1 year after operation. And we could not find any complication of biodegradable plates and screws. Conclusions: Internal fixation of the maxilla after LeFort I osteotomy using self-reinforced biodegradable plates and screws is a reliable method for maintaining postoperative position of the maxilla after LeFort I osteotomy.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.13-28
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• 2021

Since transient electronic devices can operate under harsh conditions such as electrolytic solutions or inside the body, and be removed by hydrolysis after operation, they can replace conventional electronic devices in various research areas like biomedical implantable devices. Moreover, transient electronic devices that can dissolve in water and enzymes are the focus of the new concept of green technology, which can solve electrical waste issues. However, the surroundings of transient electronic devices can deteriorate internal device components. Thus, an encapsulation strategy is introduced for stable operation in solution by shielding the outside of a device with a passive barrier. This article summarizes recent research trends in transient electronic devices, including their background, dissolution behavior, and encapsulation strategies to enhance reliability by blocking water permeation.

• Archives of Craniofacial Surgery
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• v.23 no.4
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• pp.178-182
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• 2022

Postoperative temporal hollowing is a common complication of craniotomy. Damage and repositioning of the temporalis muscle can lead to a depression in the temporal side of the skull with inferior bulging, worsening aesthetic outcomes. We report a case of cranioplasty with three-dimensional (3D) printed mesh involving an additional correction using a temporalis muscle sling to help address this problem. A 3D-printed bioabsorbable mesh was prepared based on preoperative facial computed tomography, and was fixed to the hollowed area for tissue augmentation. The temporalis muscle was elevated and fanned out to its original position, and a sling was attached to a screw that was fixed to the mesh. For reinforcement, an additional sling was attached to another screw fixed to the mesh 2-3 cm vertically above the first screw. Aesthetic results were confirmed immediately after surgery and later during outpatient follow-up. Both depression and lateral bulging were resolved, and there was no delayed drooping of the temporalis muscle on 6-month follow-up. There were no complications, and the patient was satisfied with the appearance. This is a simple yet effective technique with a low risk of complications, and should be considered for postoperative temporal hollowing patients, especially those with severe lateral bulging.

• Journal of Periodontal and Implant Science
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• v.46 no.5
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• pp.303-319
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• 2016

Purpose: The purpose of this animal study was to perform a 3-dimensional micro-computed tomography (micro-CT) analysis in order to investigate the influence of root surface distance to the alveolar bone and the periodontal ligament on periodontal wound healing after a guided tissue regeneration (GTR) procedure. Methods: Three adult Sus scrofa domesticus specimens were used. The study sample included 6 teeth, corresponding to 2 third mandibular incisors from each animal. After coronectomy, a circumferential bone defect was created in each tooth by means of calibrated piezoelectric inserts. The experimental defects had depths of 3 mm, 5 mm, 7 mm, 9 mm, and 11 mm, with a constant width of 2 mm. One tooth with no defect was used as a control. The defects were covered with a bioresorbable membrane and protected with a flap. After 6 months, the animals were euthanised and tissue blocks were harvested and preserved for micro-CT analysis. Results: New alveolar bone was consistently present in all experimental defects. Signs of root resorption were observed in all samples, with the extent of resorption directly correlated to the vertical extent of the defect; the medial third of the root was the most commonly affected area. Signs of ankylosis were recorded in the defects that were 3 mm and 7 mm in depth. Density and other indicators of bone quality decreased with increasing defect depth. Conclusions: After a GTR procedure, the periodontal ligament and the alveolar bone appeared to compete in periodontal wound healing. Moreover, the observed decrease in bone quality indicators suggests that intrabony defects beyond a critical size cannot be regenerated. This finding may be relevant for the clinical application of periodontal regeneration, since it implies that GTR has a dimensional limit.

• Polymer(Korea)
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• v.30 no.1
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• pp.14-21
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• 2006

Tissue engineering techniques require the use of a porous biodegradable/bioresorbable scaffold, which server as a three-dimensional template for initial cell attachment and subsequent tissue formation in both in vitro and in vivo. Small intestinal submucosa (SIS) has been investigated as a source of collagenous tissue with the potential to be used as biomaterials because of its inherent strength and biocompatibility. SIS-loaded poly(L-lactide-co-glicolide)(PLGA) scaffolds were prepared by solvent casting/particle leaching. Characterizations of SIS/PLGA scaffold were carried out by SEM, mercury porosimeter, and so on. Muscle-derived stem cells can be differentiated in culture into osteoblasts, chondrocytes, and even myoblasts by the controlling the culture environment. Cellular viability and proliferation were assayed by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium-bromide(MTT) test. Osteogenic differential cells were analyzed by alkaline phosphatase(ALP) activity. SIS/PLGA scaffolds were implanted into the back of athymic nude mouse to observe the effect of SIS on the osteoinduction compared with controlled PLGA scaffolds. Thin sections were cut from paraffin embedded tissues and histological sections were conducted hematoxylin and eosin (H&E), Trichrome, and von Kossa. We observed that bone formatioin of SIS/PLGA hybrid scaffold as natural/synthetic scaffold was better thean that of only PLGA scaffold. It canb be explained that SIS contains various kinds of bioactive molecules for osteoinduction.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.305-324
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• 2000

This study compared the short-term(4 months) clinical results of regenerative therapy with bioabsorbable membranes($BioMesh^{(R)}$) and bone allograft for the treatment of periodontal(intrabony and furcation) defects in smokers and nonsmokers.(16 smokers) 32 subjects with 92 defects participated in the study(46 in smokers and 46 in non-smokers). This study also evaluated a bioresorbable barrier with and without decalcified freeze-dried bone allograft(DFDBA). The 92 periodontal defects were randomly treated with either the resorbable barrier alone or resorbable barrier in combination with DFDBA following thorough defect debridement and root preparation with tetracycline. Each patient received both types of treatment modalities. Clinical examinations(probing depth, gingival recession, clinical attachment level, plaque index and gingival index) were carried out immediately before and 4 months after surgery. Significant(p<0.001) gains in mean attachment level were observed for both smokers(2.93mm) and non-smokers(3.30mm) but there were not significant difference between two groups. Similarly, significant reductions in mean probing depthshowed for smokers(4.52mm) and non-smokers(4.26mm). However, when comparing gingival recession, smokers were found to exhibit significantly poorer treatment results(1.59mm vs 0.96mm, p<0.05). Using the split-mouth-design, no statistically significant difference between the two modalities could be detected with regard to pocket depth reduction, gingival recession, or attachment gain. These results illustrate that the attachment gain is better in the non-smoker and the best in the non-smoker with the combination therapy of resorbable barrier and DFDBA than with resorbable barrier alone but smoking had no significant effect on clinical treatment outcome, even though smokers show more significant gingival recession. In addition, both treatments, either resorbable barrier plus DFDBA or resorbable barrier alone, promoted significant resolution of periodontal defects but the addition of DFDBA with a bioabsorbable membrane appears to add no extra benefit to the only membrane treatment.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.217-234
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• 1997

The purpose of present study is to compare the effect of treatment using $Guidor^{(R)}$ as a barrier membrane in conjunction with platelet-derived growth factor and insulin like growth factors on experimental dehiscence defects. Following the resection of premolar crowns, roots were submerged. After 12 weeks of healing period, experimental dehiscence defects of 4mm in height and 4mm in width were surgically created on the mid-facial aspect of the lower premolar roots in each of 4 adult dogs. After root planning and demineralization of the root surface with citric acid, the control groups received 4% methylcellulose gel only, the test group I received 4% methylcellulose gel and were covered by $Guidor^{(R)}$ and the test group II were treated with PDGF and IGF and 4% methylcellulose gel with $Guidor^{(R)}$ coverage. Histological and histomorphometric analysis following 8 weeks of healing revealed the following results. 1. The new bone formation showed no statistically significant difference in all groups with $0.59{\pm}0.82mm$($14.03{\pm}19.60%$) for control, $0.70{\pm}0.39mm$($16.30{\pm}9.01%$) for group I, $0.87{\pm}0.76mm$($18.74{\pm}16.03%$) for group II. 2. The new cementum formation showed no statistically significant difference in all groups with $0.54{\pm}0.48mm$($l6.38{\pm}14.57%$) for control, $0.95{\pm}0.38mm$($23.43{\pm}9.30%$) for group I, $1.01{\pm}0.75mm$($22.10{\pm}16.ll%$) for gorup II. 3. The root resorption showed statistically significant differences betweenthe control group and all test groups(p<0.05) with $2.11{\pm}0.53mm$($52.93{\pm}12.32%$) for control, $0.63{\pm}0.27mm$($15.32{\pm}7.05%$) for group I, $0.89{\pm}0.33mm$ ($19.26{\pm}7.11%$) for group II. On the bases of these results, there were no statistically difference between treatment using resorbable membrane and resorbable membrane in conjunction with PDGF and IGF in the dehiscence defects, where it was difficult to maintain space. The use of membrane seemed to be more effective in the inhibition of root resorption.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.6
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• pp.481-491
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• 2005

Purpose: The aim of the present study is to evaluate the effect of autogenous bone and allograft material coverd with a bioresorbable membrane on bone regeneration after a simultaneous installation of implant. Materials and methods: Twelve healthy rabbits, weighing about $3{\sim}4$ kg, were used in this experiment. Following impalnt(with 3.25 mm diameter and 8 mm length) site preparation by surgical protocol of $Oraltronics^{(R)}$, artificial bony defect, 5mm sized in height and depth, was created on femoral condyle using trephine drill(with 5 mm diameter and 5 mm length). Then implant was inserted. In the experimental group A, the bony defect was filled with autogenous particulated bone and coverd with $Lyoplant^{(R)}$ resorbable membrane. In the experimental group B, the bony defect was filled with allograft material(Orthoblast $II^{(R)}$) containing demineralized bone matrix and covered with $Lyoplant^{(R)}$. In the control group, without any graft materials, the bony defect was covered with $Lyoplant^{(R)}$. The experimental group A and B were divided into each 9 cases and control group into 3 cases. The experimental animals were sacrificed at 3, 6 and 8 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E staining and then, measured BIC and bone density with KAPPA Image $Base^{(R)}$ system. Results: As a result of this experiment, bone formation and active remodeling process were examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. Especially bone to-implant contact fraction ranged from 12.7% to 43.45% in the autogenous bone group and from 9.02% to 29.83% in DBM group, at 3 and 8 weeks. But, bone density ranged from 15.67% to 23.17% in the autogenous bone group and from 25.95% to 46.06% in DBM group at 3 and 6 weeks, respectively. Although the bone density of DBM group was better than that of autogenous bone group at 3 and 6weeks, the latter was better than the former at 8 weeks, 54.3% and 45.1%, respectively. Therefore these results showed that DBM enhanced the density of newly formed bone at least initially.