• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.2
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• pp.116-126
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• 2009

The use of short implants has been accepted risky from biomechanical point of view. However, short implants appear to be a long term viable solution according to recent clinical reports. The purpose of this study was to investigate the effect of different diameter and length of implant size to the different type of bone on the load distribution pattern. Stress analysis was performed using 3-dimensional finite element analysis(3D-FEA). A three-dimensional linear elastic model was generated. All implants modeled were of the various diameter(${\phi}4.0$, 4.5, 5.0 and 6.0 mm) and varied in length, at 7.0, 8.5 and 10.0 mm. Each implant was modeled with a titanium abutment screw and abutment. The implants were seated in a supporting D2 and D4 bone structure consisting of cortical and cancellous bone. An amount of 100 N occlusal load of vertical and $30^{\circ}$ angle to axis of implant and to buccolingual plane were applied. As a result, the maximum equivalent stress of D2 and D4 bones has been concentrated upper region of cortical bone. As the width of implant is increased, the equivalent stress is decreased in cancellous bone and stress was more homogeneously distributed along the implants in all types of bone. The short implant of diameter 5.0mm, 6.0mm showed effective stress distribution in D2 and D4 bone. The oblique force of 100N generated more concentrated stress on the D2 cortical bone. Within the limitations of this study, the use of short implant may offer a predictable treatment method in the vertically restricted sites.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.280-289
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• 2018

Purpose: The purpose of this randomized clinical trial is to determine whether implant length and the crown-to-implant (C/I) ratio influence implant stability and peri-implant marginal bone loss (MBL). Materials and Methods: 46 patients with single tooth missing in the posterior molar region of the mandible were included in this study. 19 implants (CMI IS-III $active^{(R)}$ long implant) of 5.0 mm diameter and 10 mm length were installed for the control group, while 27 implants (CMI IS-III $active^{(R)}$ short implant) of 5.5 mm diameter and 6.6, 7.3 or 8.5 mm length were placed for the experimental group. Each implant was inserted and immediately loaded using the digitally pre-fabricated surgical template and provisional restoration. The CAD-CAM monolithic zirconia crown was fabricated at 3 months after the surgery as a definitive restoration. The ISQ value and the MBL was measured at 48 weeks after the surgery. The correlation between the C/I ratio, MBL, and secondary implant stability was analyzed. Results: Successful results in terms of ISQ and MBL were achieved with both groups. There was no significant difference between the groups in terms of ISQ values and MBL at 48 weeks after the surgery (P > 0.05). No significant correlation was found between the C/I ratio and secondary stability as well as the C/I ratio and the MBL (P > 0.05). Conclusion: The influence of C/I ratio in both groups was not shown on the stability nor the marginal bone loss in implants supporting single crown of the mandible. Short implant could be a preferable alternative option in the reduced bone height mandible under the limited condition despite its higher C/I ratio.

• Journal of Korean Dental Science
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• v.2 no.2
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• pp.24-30
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• 2009

Two component orthodontic C-implants have been introduced as intermaxillary fixation (IMF) screws in cases of periodontal problems with bone loss, severely damaged teeth, or short roots. This retrospective research sought to investigate the complications and risk factors associated with the failure of two-part C-implants for IMF cases and to show the possible indications compared to one-component mini-implants. The study sample consisted of 46 randomly selected patients who had a total of 203 implants. Pearson chi-square tests of independence were used to test for associations among categorical variables. At least 19 of the total 203 implants failed (9.3%). There was no significant difference in implant failure due to gender, oral hygiene, and placement, although a significant difference due to soft tissue characteristics and root contact was observed. The two-component design of the mini-implant is reliable for difficult IMF cases. Note, however, that the factors influencing implant failure were found to be age, root damage, and condition of soft tissues.

• The Journal of Advanced Prosthodontics
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• v.8 no.1
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• pp.62-69
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• 2016

PURPOSE. The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. MATERIALS AND METHODS. Forty screw-retained single crowns were connected to external and internal hex implants. The prepared titanium abutment screws were classified into 8 groups based on the number of threads (n = 5 per group): EH 12.5, 6.5, 3.5, 2.5 and IH 6.5, 5, 3.5, 2.5 threads. The abutment screws were tightened with 20 Ncm torque twice with 10-minute intervals. After 5 minutes, the initial RTVs of the abutment screws were measured with a digital torque gauge (MGT12). A customized jig was constructed to apply a load along the implant long axis at the central fossa of the maxillary first molar. The post-loading RTVs were measured after 16,000 cycles of mechanical loading with 50 N at a 1-Hz frequency. Statistical analysis included one-way analysis of variance and paired t-tests. RESULTS. The post-loading RTVs were significantly lower than the initial RTVs in the EH 2.5 thread and IH 2.5 thread groups (P<.05). The initial RTVs exhibited no significant differences among the 8 groups, whereas the post-loading RTVs of the EH 6.5 and EH 3.5 thread groups were higher than those of the IH 3.5 thread group (P<.05). CONCLUSION. Within the limitations of this study, the external hex implants with short screw lengths were more advantageous than internal hex implants with short screw lengths in torque maintenance after cyclic loading.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.671-679
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• 2007

Background: $TiUnite^{TM}$ is a highly crystalline and phosphate enriched titanium oxide surface which has a unique porous surface structure. This improved implant surface enhances bone response and reduces healing period. It also assures early stability of implant. These help to increase the success of implant. The aim of this study is to evaluate the survival rate of $TiUnite^{TM}$ surfaced single implant. Materials and methods: A retrospective analysis of 89 $TiUnite^{TM}$ surfaced implants replacing a single tooth was assessed according to their dental record. The age of the patients ranged from 17 to 82 years (mean age: $45.8{\pm}14.6)$. Data were recorded regarding the survival rate of these implants. Results: Fifty-two implants (57%) were placed in the maxilla, and 37 (43%) in the mandible. Over 75% were placed in the posterior area. Of the placed implants, 67% were the wide type. while 25% were the regular type and only 8% were of the narrow type. The single implants produced an overall clinical survival rate of 96.6% over the observation period (mean 17.9 months). Among 89 implants, only 2 implants were removed and one implant was submerged. Conclusion: According to these data, $TiUnite^{TM}$ surfaced implant in a single tooth restoration showed favorable survival rate although this study was done in a short term period.

• Journal of Periodontal and Implant Science
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• v.38 no.3
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• pp.413-428
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• 2008

Purpose: Given the predictability of dental implant procedure from the studies of successful osseointegration, implant dentistry is often the treatment of choice to replace missing teeth in edentulous patient instead of the fixed prosthesis or removable denture. The $Renova^{(R)}$ dental implant has a RBM(Resorbable Blast Media) surface, internal hex prosthetic connection and a tapered design. At this study gives the analysis of the implant and the short term survival rate of the implant. Material and Methods: In this study, a multilateral analysis was performed on the subjects undergoing placement with $Renova^{(R)}$ implant between August 2006 and February 2008 in Yonsei University dental hospital. 96 implants were placed in 56 patients and they were surveyed for cumulative survival rate. Among them 78 implants in 44 patients were surveyed for the rest analyses. Result: 1. The cumulative survival rate was 96.88% of 96 implants in 56 patients. 2. The mean marginal bone loss was 0.803mm and the marginal bone loss in augmentation group has higher value than the marginal bone loss in non augmentation group. 3. The health scale for the implants were 87% in success group, 9% in satisfactory survival group, 1% in compromised survival group, and 3% in failure group. 4. Two implants placed in poor bone posterior area by 2-stage failed during prosthetic procedure. Conclusion: $Renova^{(R)}$ dental implant showed high cumulative survival rate in installation on partial edentulous ridge and could be a predictable implant system.

• Journal of Korean Dental Science
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• v.10 no.2
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• pp.87-95
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• 2017

This case study was to report the possible increase in the denture retention and psychological relief using the implant-supported fixed prostheses in a completely edentulous patient. The implants were placed in the anterior portion of the mandible in a patient who had completely edentulous state following the extraction of residual abutment teeth, and consequently a distal extension removable partial denture was fabricated. The patient's adaptation and satisfaction to the new prosthesis was monitored and confirmed in terms of masticatory function and esthetics, by restoring the oral condition similar to initial status before the residual teeth extraction. After 6 months, radiographic examination confirmed that both the abutment teeth and the implants were stable and well maintained. Considering the relatively short clinical follow-up period, however, continuous long-term monitoring was required.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.3
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• pp.175-182
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• 2021

Objectives: In this prospective randomized controlled trial, we measured the primary and secondary stability of two surface-treated implants placed in the posterior maxilla, applied 3-month loading protocols, and compared and analyzed the short-term outcomes of the implants. Patients and Methods: From June 2018 to June 2019, patients with a residual bone height of 4 mm in the posterior maxilla were enrolled and randomly divided into two groups to place SA implants (Osstem Implants, Korea) in Group A and NH implants (Hiossen, USA) in Group B. Finally, 14 implants placed in 13 patients in Group A and 17 implants placed in 14 patients in Group B were analyzed. The measured primary and secondary stability of each implant was represented by implant stability quotient (ISQ), and treatment outcomes were evaluated. Results: Group A consisted of patients with an average age of 62.2 years (range, 48-80 years), and Group B consisted of patients with an average age of 58.1 years (range, 35-82 years). Primary stability was 73.86±6.40 and 71.24±5.32 in Groups A and B, respectively (P=0.222). Secondary stability was 79.07±5.21 in Group A and 78.29±4.74 in Group B (P=0.667). A steep increase in ISQ during the healing period was observed in Group B, though it was not significant (P=0.265). The mean follow-up period was 378.5±164.6 days in Group A and 385.3±167.9 days in Group B. All implants in each group met the success criteria, and the success rate was 100%. Conclusion: Two surface-treated implants placed in the posterior maxilla with greater than 4 mm alveolar bone height exhibited successful one-year treatment outcomes if a primary stability of 65 or higher ISQ was obtained and a 3-month early loading protocol was applied.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.3
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• pp.360-365
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• 2000

The completely edentulous patient has few treatment options in conventional dentistry. When implants are considered, treatment plans range from a 2-implant overdenture to a completely implant-supported prosthesis. Fixed prosthesis is often the preferred selection of the edentulous patient. fixed full-arch cert amo-metal restorations can be a predictable implant treatment modality for the edentulous patient. Implant-supported fixed prosthesis has several advantages: predictability, fixedness, retrievability, improved function, lower maintenance of prosthesis, long-term published success. Edentulous patients with a severely resorbed mandible often experience problems with their dentures. Treatment concepts involving two to four implants for the support of an overdenture have been proposed. There seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion. Using short endosseous implants and an overdenture in the extremely resorbed mandible is a justified treatment option because of the relative simplicity and low morbidity of this treatment strategy. Implant-supported overdenture has several advantages: Cost, retrievability, hygiene access, profile and contour control, increased retention and stability, implant installed in a predicted region(ant. mandible).

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.3
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• pp.267-277
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• 2009

Recently implant supported single crown is the popular treatment option to replace a single missing tooth. The purpose of this retrospective study was to analyze and evaluate the survival of implants with the $TiUnite^{TM}$ surface for single tooth replacement. From September 2002 to December 2006, 269 TiUniteTM surfaced implants were used in single tooth replacements at the Institute of Oral Health Science, Samsung Medical Center. Twenty one cases were excluded because of neighbor implants, missing records & short follow up period. Among 248 implants, the 129 implants (52.0%) were inserted in the maxilla and 119 (48.0%) in the mandible. One hundred implants placement (40.3%) were combined with guided bone regeneration, and 36 implants placement (14.5%) were combined with sinus bone augmentation. Mean observation period was $26.0{\pm}11.8$ months after implant placement. Twelve implants were recorded as failures, rendering a single implant survival rate of 95.2% over the observation period. Among failed 12 implants, 10 implants placed in the maxilla. The survival rate in the maxilla was 92.2% and in the mandible was 98.3%. The use of $TiUnite^{TM}$ surfaced single implant placement showed high survival rate for short time period.