STATEMENT OF PROBLEM: Resonance frequency analysis has been increasingly served as a noninvasive and objective method for clinical monitoring of implant stability. Many clinical studies must be required for standardized data using RFA. PURPOSE: This study was performed to evaluate RFA value changes in two anodized implant groups. MATERIAL AND METHOD: Among a total of 24 implants, twelve screw shaped implants as a test group (H2-R8.5) were manufactured, which had a pitch-height of 0.4 mm, an outer diameter of 4.3 mm, a length of 8.5 mm, and external hexa-headed, were turned from 5 mm rods of commercially pure titanium (ASTM Grade IV, Warantec Co., Seoul, Korea), and another twelve implants as a control group were Branemark Ti-Unite MK4 (diameter 4.0 mm, length 8.5 mm). Each group was installed in tibia of rabbit. Two implants were placed in each tibia (four implants per rabbit). Test two implants were inserted in right side and control two in left side. ISQ values were measured using Osstell(TM) (Integration Diagnostics Ltd. Sweden) during fixture installation, and 12 weeks later and evaluated the RFA changes. RESULTS: Mean and SD of baseline ISQ values of test group were 75.0 +/- 3.4 and 68.7 +/- 8.1 for control group. Mean and SD of ISQ values 12 weeks after implant insertion were 73.2 +/- 4.7 for test group and 72.6 +/- 3.9 for control group. There were no statistically significant differences between groups in ISQ values after 3months (P>0.05). From the data, RFA gains after 3 months were calculated, and there was statistically significant difference between groups (P<0.05). CONCLUSION: Although there were RFA changes between groups, implant stability after experimental period shows alike tendency and good bone responses.
Seoul ; Tibia ; Titanium

STATEMENT OF PROBLEM: It is difficult about assessing the loosening tendency of conical connection type implant after cyclic loading with diamond like carbon coating one-piece abutments, and also about the retightening effect. PURPOSE: This study was performed to investigate the influence of one-piece abutment screw retightening after 5.0X10(4) cyclic loading and Diamond like coating MATERIAL AND METHODS: Thirty two ITI implant were divided to 4 groups. Group 1,3-titanium abutment, group 2,4 - diamond like carbon coated abutment. Group 1,2 - 20.0X10(4) cyclic loading after 5.0X10(4) cyclic loading, Group 3,4- after 20.0X10(4) Cyclic loading. After cyclic loading, periotest values were taken and removal torque values of abutments were measured with a digital torque gauge. RESULTS: 1. The removal torque of group 2 after 5.0X10(4) cyclic loading is slightly greater than the other groups but not significantly higher than others (P>0.05). 2. The final removal torque values after 20.0X10(4) cyclic loading of group 1 is bigger than group 3, and group 2 is bigger than group 4, but not significantly higher (P>0.05). 3. The final removal torque values after 20.0X10(4) cyclic loading of all groups are not significantly different (P>0.05).
Carbon ; Diamond ; Torque

PURPOSE: To date most of finite element analysis assumed the presence of 100% contact between bone and implant, which is inconsistent with clinical reality. In human retrieval study bone-implant contact (BIC) ratio ranged from 20 to 80%. The objective of this study was to explore the influence of bone-implant contact pattern on bone of the interface using nonlinear 3-dimensional finite element analysis. MATERIALS AND METHODS: A computer tomography-based finite element models with two types of implant (Mark III Branemark(R), Inplant(R)) which placed in the maxillary 2nd premolar area were constructed. Two different degrees of bone-implant contact ratio (40, 70%) each implant design were simulated. 5 finite element models were constructed each bone-implant contact ratio and implant design, and sum of models was 40. The position of bone-implant contact was determined according to random shuffle method. Elements of bone-implant contact in group W (wholly randomized osseointegration) was randomly selected in terms of total implant length including cortical and cancellous bone, while ones in group S (segmentally randomized osseointegration) was randomly selected each 0.75 mm vertically and horizontally. RESULTS: Maximum von Mises strain between group W and group S was not significantly different regardless of bone-implant contact ratio and implant design (P=.939). Peak von Mises strain of 40% BIC was significantly lower than one of 70% BIC (P=.007). There was no significant difference between Mark III Branemark(R) and Inplant(R) in 40% BIC, while average of peak von Mises strain for Inplant(R) was significantly lower (4886 +/- 1034 microm/m) compared with MK III Branemark(R) (7134 +/- 1232 microm/m) in BIC 70% (P<.0001). CONCLUSION: Assuming bone-implant contact in finite element method, whether the contact elements in bone were wholly randomly or segmentally randomly selected using random shuffle method, both methods could be effective to be no significant difference regardless of sample size.
Bicuspid ; Finite Element Analysis ; Humans ; Nitrogen Mustard Compounds ; Sample Size ; Sprains and Strains

Purpose: This study was conducted in order to examine the usefulness of osteoconductive bone substitutes with zeta potential control (geneX® ds; Biocomposites, England) by comparing the complications and radiographic evaluation with or without geneX® ds augmentation for internal fixation with proximal femur nail antirotation (PFNA) for treatment of osteoporotic unstable intertrochanteric fractures. Materials and Methods: A retrospective study of 101 patients who underwent fixation with PFNA in osteoporotic unstable intertrochanteric fractures was conducted from December 2015 to August 2020. The radiographic evaluation and complication rates were compared between patients with geneX® ds (Group A: 41 cases) and those without geneX® ds (Group B: 60 cases). Results: In radiological valuation, the degree of blade sliding from the time immediately after surgery to one year after surgery was 1.4±1.2 mm and 5.8±2.7 mm in Group A and Group B, respectively (P<0.001). During the same time frame, a significant difference of 2.3±2.2° and 7.4±3.1° , respectively (P<0.001), in varus collapse, was observed for Group A and Group B. Conclusion Among patients fixed with PFNA for treatment of unstable intertrochanteric fractures, less blade sliding and varus collapse was observed for those with geneX® ds augmentation compared to those without it. In addition, there was no increase in the incidence of complications. The authors believe it can be regarded as a safe and effective additive for intramedullary fixation for treatment of unstable intertrochanteric fractures.

The study was the clinical analysis of 509 patients with pure ocular injuries who visited to Chonnam University Hospital Emergency center from July 1, 1996 to June 30, 1997 retrospectively. Clinical data survey including sex and age distribution, causes of trauma, injury site, ocular disease, and surgical intervention was done. Most of ocular injury patients were male. 3rd and 4th decade who were socially active were nearly 50%. Direct and indirect injury from foreign body was the most common cause of ocular injuries followed by fist blow, traffic accident, falling down, and sport injury. Cornea was the most common ocular injury site (209 patients, 41.1%). The incidence of the traumatic ocular disease showed corneal erosion (117 patients, 22.9%) and then eyeball perforation, traumatic hyphema etc. by frequency of order. Eyeball perforation was the most common ocular injury which needed a emergency surgical intervention. As a results, emergency physicians have to pay attention to the cornea in case of any type of ocular injuries and eyeball perforation which caused by direct and indirect injury from foreign body.
Accidents, Traffic ; Age Distribution ; Cornea ; Emergencies ; Foreign Bodies ; Humans ; Hyphema ; Incidence ; Jeollanam-do ; Male ; Retrospective Studies ; Sports

BACKGROUND: We postulate that a delay in the implementation of hepatic arterial embolization for traumatic liver injury patients will negatively affect patient prognosis. Our work also seeks to identify factors related to the mortality rate among traumatic liver injury patients. METHODS: From January 2008 to April 2014, patients who had been admitted to the emergency room, were subsequently diagnosed with traumatic liver injury, and later underwent hepatic arterial embolization were included in this retrospective study. RESULTS: Of the 149 patients that underwent hepatic arterial embolization, 86 had the procedure due to traumatic liver injury. Excluding the 3 patients that were admitted to the hospital before procedure, the remaining 83 patients were used as subjects for the study. The average time between emergency room arrival and incidence of procedure was 164 min for the survival group and 132 min for the non-survival group; this was not statistically significant (p = 0.170). The average time to intervention was 182 min for the hemodynamically stable group, and 149 min for the hemodynamically unstable group, the latter having a significantly shorter wait time (p = 0.047). Of the factors related to the mortality rate, the odds ratio of the Glasgow Coma Score (GCS) was 18.48 (p < 0.001), and that of albumin level was 0.368 (p = 0.006). CONCLUSIONS: In analyzing the correlation between mortality rate and the time from patient admission to arrival for hepatic arterial embolization, there was no statistical significance observed. Of the factors related to the mortality rate, GCS and albumin level may be used as prognostic factors in traumatic liver injury.
Coma ; Embolization, Therapeutic ; Emergency Service, Hospital ; Humans ; Incidence ; Liver* ; Mortality* ; Odds Ratio ; Patient Admission ; Prognosis ; Retrospective Studies ; Time Factors

Dislodgement of a crown or extension bridge and the loosening of a retainer of a bridge is a serious clinical problem in fixed restoration. Generally these problems are considered to be associated with deformation of the restoration. During biting, the restoration is subjected to complex forces and deforms considerably within the limit of its elasticity. Deformation of the restoration under the occlusal force induces excessive stress in the cement film, which then leads to the cement fracture. Such a fracture may eventually cause loss of the restoration. Because most of the past retention tests for full veneer crown were done without fatigue loading, they were not exactly simulating intraoral environment. And the purpose of this study was to evaluate the effect of cyclic cantilever loading on the retentive strength of full veneer crowns depending on different type of cements and taper of prepared abutment. Steel dies with 8degrees or 16degrees convergence angle were fabricated through milling and crowns with the same method. These dies and crowns were divided into 8 groups. Group 1: 16degrees taper die, cementation with zinc phosphate cement, without loading Group 2: 16'taper die, cementation with zinc phosphate cement, with loading Group 3: 8degrees taper die, cementation with zinc phosphate cement, without loading Group 4: 8degrees taper die, cementation with zinc phosphate cement, with loading Group 5: 16degrees taper die, cementation with Panavia 21, without loading Group 6: 16degrees taper die, cementation with Panavia 21, with loading Group 7: 8degrees taper die, cementation with Panavia 21, without loading Group 8: 8degrees taper die, cementation with Panavia 21, with loading After checking the fit of die and crown, the luting surface of dies and inner surface of crowns were air-abraded for 10 seconds. The crowns were cemented to the dies, with cements mixed ac cording to the manufacturer' s recommendations. A static load of 5 kg was then applied for 10 min utes with static loading device. Twenty-four hours later, group 1,3,5,7 were only thermocycled, group 2,4,6,8 were subjected to cyclic loading after thermocycling. Retentive tests were performed on the Instron machine. From, the finding of this study, the following conclusions were obtained. 1. Panavia 21 showed significantly higher retentive strength than zinc phosphate cement for all groups(p<0.05). 2. There was a significant difference in the retentive strength between 8degrees and 16degrees taper for zinc phosphate cement(p<0.05), but no significant difference for Panavia 21(p>0.05). 3. Cyclic loading significantly decreased the retentive strength for all groups (p<0.05) . 4. For zinc phosphate cement, there was 35% reduction of the retentive strength after loading in the 16degrees taper die, 25% in the 8degrees taper die, and for Panavia 21, 21% in the 16degrees taper die, 18% in the 8degrees taper die.
Bite Force ; Cementation ; Crowns* ; Elasticity ; Fatigue ; Steel ; Zinc ; Zinc Phosphate Cement

Statement of problem. Titanium is the most important material for biomedical and dental implants because of their high corrosion resistance and good biocompatibility. These beneficial properties are due to a protective passive oxide film that spontaneously forms on the surface. Purpose. The purpose of this study was to evaluate the responses of osteoblast-like cells on different surface treatments on Ti discs. Material and Methods. Group 1 represented the machined surface with no treatment. Group 2 surfaces were sandblasted with 50microm Al2O3 under 5 kgf/cm2 of pressure. Groups 3 and 4 were sandblasted under the same conditions. The samples were treated on a titanium oxide surface with reactive sputter depositioning and thermal oxidation at 600degree C (Group 3) and 800degree C (Group 4) for one hour in an oxygen environment. The chemical composition and microtopography were analyzed by XRD, XPS, SEM and optical interferometer. The stability of TiO2 layer was studied by potentiodynamic curve. To evaluate cell response, osteoblast extracted from femoral bone marrow of young adult rat were cultured for cell attachment, proliferation and morphology on each titanium discs. Results and Conclusion. The results were as follows : 1.Surface roughness values were, from the lowest to the highest, machined group, 800degree C thermal oxidation group, 600degree C thermal oxidation group and blasted group. The Ra value of blasted group was significantly higher than that of 800degree C thermal oxidation group (P=0.003), which was not different from that of 600degree C thermal oxidation group (P<0.05). 2. The degree of cell attachment was highest in the 600degree C thermal oxidation group after four and eight hours (P<0.05), but after 24 hours, there was no difference among the groups (P>0.05). 3. The level of cell proliferation showed no difference among the groups after one day, three days, and seven days (P>0.05). 4. The morphology and arrangement of the cells varied with surface roughness of the discs.
Animals ; Bone Marrow ; Cell Proliferation ; Corrosion ; Dental Implants ; Humans ; Osteoblasts ; Oxygen ; Rats ; Titanium* ; Young Adult

BACKGROUND: Since the establishment of biological augmentation to improve the treatment of rotator cuff tears, it is imperative to explore newer techniques to reduce the retear rate and improve long-term shoulder function after rotator cuff repair. This study was undertaken to determine the consequences of a gel-type atelocollagen injection during arthroscopic rotator cuff repair on clinical outcomes, and evaluate its effect on structural integrity. METHODS: Between January 2014 and June 2015, 121 patients with full thickness rotator cuff tears underwent arthroscopic rotator cuff repair. Of these, 61 patients were subjected to arthroscopic rotator cuff repair in combination with an atelocollagen injection (group I), and 60 patients underwent arthroscopic rotator cuff repair alone (group II). The visual analogue scale (VAS) for pain and the Korean Shoulder Society (KSS) scores were evaluated preoperatively and postoperatively. Magnetic resonance imaging (MRI) was performed at 6 months postoperatively, to assess the integrity of the repair. RESULTS: VAS scores were significantly lower in group I than in group II at 3, 7, and 14 days after surgery. KSS scores showed no significant difference between groups in the 24 months period of follow-up. No significant difference was obtained in the healing rate of the rotator cuff tear at 6 months postoperatively (p=0.529). CONCLUSIONS Although a gel-type atelocollagen injection results in reduced pain in patients at 2 weeks after surgery, our study does not substantiate the administration of atelocollagen during rotator cuff repair to improve the clinical outcomes and healing of the rotator cuff.

PURPOSE: In patients with independent mobility, full hip range of motion and sufficient muscle strength for daily life without cognitive impairment, treatment of a femoral neck fracture with total hip arthroplasty (THA) may be a better option compared to bipolar hip hemiarthroplasty. Here, functional outcomes and complications in patients who underwent THA for femoral neck fracture based on their comorbidity status were analyzed. MATERIALS AND METHODS: Between January 2013 and December 2018, 110 patients were treated with THA for femoral neck fractures at our institution. These patients were retrospectively analyzed for clinical outcomes at final follow-up (mean=24.4 months, range: 6–81 months) using the Harris hip score (HHS) and the presence or absence of two potential comorbidities: i) diabetes mellitus (DM; 35 with and 75 without) and ii) hypertension (HTN; 50 with and 60 without). RESULTS: The incidence of superficial infections at the surgical site in patients with DM was significantly higher compared with patients without DM (P=0.024). There were no significant differences in other potential complications based on DM status. HHS at final follow-up between patients with and without DM and with and without HTN were not significantly different (83.3 vs. 81.0, P=0.39 and 81.6 vs. 82.4, P=0.75, respectively). CONCLUSION: Superficial infections occurred more frequently in patients with DM compared with patients without DM. DM and HTN status are not correlated with HHS.
Arthroplasty, Replacement, Hip ; Cognition Disorders ; Comorbidity ; Diabetes Mellitus ; Femoral Neck Fractures ; Femur Neck ; Follow-Up Studies ; Hemiarthroplasty ; Hip ; Humans ; Hypertension ; Incidence ; Muscle Strength ; Range of Motion, Articular ; Retrospective Studies