• Journal of Periodontal and Implant Science
• /
• v.49 no.1
• /
• pp.47-57
• /
• 2019

Purpose: This study was designed to observe the resorption pattern of biphasic calcium phosphate (BCP) used for maxillary sinus augmentation over a 3- to 6-year healing period, and to investigate factors affecting the resorption of BCP. Methods: A total of 47 implants placed in 27 sinuses of 22 patients were investigated. All patients had residual bone height less than 5 mm at baseline. The modified Caldwell-Luc approach was used to elevate the maxillary sinus membrane, and the sinus cavity was filled with BCP (70% hydroxyapatite and 30% ${\beta}$-tricalcium phosphate). Implant placement was done simultaneously or in a staged manner. Serial radiographic analysis was performed up to 6 years postoperatively. Results: During the follow-up period, no implant loss was reported. The mean reduced height of the augmented sinus (RHO) was $0.27{\pm}1.08mm$ at 36 months, and $0.89{\pm}1.39mm$ at 72 months postoperatively. Large amounts of graft material (P=0.021) and a long healing period (P=0.035) significantly influenced the amount of RHO. In particular, there was a significant relationship between a healing period longer than 40 months and RHO. Conclusions: BCP can achieve proper dimensional stability with minimal reduction of the graft height in a 3- to 6-year healing period after maxillary sinus augmentation. The healing period and the amount of graft material influenced the resorption of BCP.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1996.04a
• /
• pp.95-100
• /
• 1996

This paper presents the experimental study on hardening process of high-strength and high-flowable concrete. The experiments were performed to investigate any unfavorable construction situations since the actual concrete placement has been scheduled in cold weather period, so that the high quality concrete construction is convinced to be successfully carried out. The tests were conducted using 600nm and 1000nm height of steel tube to simulate the practical concrete filled steel tube columns according to the following variables as: the categories of chemical admixtures, curing temperatures and curing schemes. The test results were analyzed in terms of hardening speed, internal heat of hydration and history of strength gain. This paper emphasizes the importance of curing schemes on durability and the use of hardening accelerators on strength gain.

• The Journal of the Korean dental association
• /
• v.37 no.4 s.359
• /
• pp.279-286
• /
• 1999

In patients with severely atrophic mandibular posterior area, implant placement is a problematic surgical procedure. Inferior alveolar nerve transpositioning technique offers better initial stability of implant and reduce the risk of permanent nerve damages. In this case report, the patient has bilateral atrophic mandibular posterior edentulous area. We placed 3 implants on each mandibular posterior area in conjunction with bilateral inferior alveolar nerve transpositioning to achieve sufficient bone height. The patient complained of paresthesia in lower lip and chin area and ptosis of lower lip after surgery. Neurosensory function was normal in 10 weeks after surgery.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.22 no.1
• /
• pp.83-85
• /
• 2000

The purpose of this study is to evaluate the effect of $HTR^{TM}$ (hard tissue replacement, Bioplant Inc, U.S.A) polymer on short-term healing as a grafting material for alveolar ridge augmentation. A 48-year-old female presented insufficient bone height and width for the placement of implants. $HTR^{TM}$ polymer was used for ridge augmentation. Bone biopsy was harvested 8 months after the ridge augmentation procedure. $HTR^{TM}$ polymer displayed rapid bone regeneration and mature lamellar and trabecular bone redevelopment. Clinical and histologic observation from the treatment of the patient presented suggest that $HTR^{TM}$ polymer seems to be a appropriate material for alveolar ridge augmentation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.46 no.3
• /
• pp.211-217
• /
• 2020

In patients with insufficient bone height and width, the successful placement of dental implants is difficult with regards to maintaining an ideal pathway and avoiding important anatomical structures. Vertical and/or horizontal ridge augmentation may be necessary using various bone substitute materials and bone graft procedures. However, effective one-wall reconstruction has been challenging due to its poor blood supply and insufficient graft stability. In this paper, the authors summarize current evidence-based literature based on the author's clinical experience. Regarding bone substitutes, it is advantageous for clinicians to select the types of bone substitutes including autogenous bone. The most important consideration is to minimize complications through principle-based ridge augmentation surgery. Ridge augmentation should be decided with complete consent of the patients due to the possible disadvantages of surgery, complications, and unpredictable prognosis.

• Journal of International Society for Simulation Surgery
• /
• v.1 no.2
• /
• pp.90-94
• /
• 2014

Reconstruction of the mandible after ablative oral cancer surgery requires esthetic and functional rehabilitation. Restoring facial symmetry and dentition need accurate preoperative surgical planning and meticulous surgical technique. Free fibular flap is most useful tools to reconstruct mandible because of its adequate length and height, simultaneous harvest of soft and hard tissues and placing dental implants. In this case report, recurred squamous cell carcinoma in the right mandible had been resected and free fibular flap was utilized for mandible reconstruction using 3D rapid prototype. Simulation surgery before dental implant placement has been performed for esthetic and functional prosthodontics.

• The Journal of Advanced Prosthodontics
• /
• v.8 no.2
• /
• pp.150-157
• /
• 2016

PURPOSE. The modified lateral-screw-retained implant prosthesis (LSP) is designed to combine the advantages of screw- and cement-retained implant prostheses. This retrospective study evaluated the mechanical and biological complication rates of implant-supported single crowns (ISSCs) inserted with the modified LSP in the posterior region, and determined how these complication rates are affected by clinical factors. MATERIALS AND METHODS. Mechanical complications (i.e., lateral screw loosening [LSL], abutment screw loosening, lateral screw fracture, and ceramic fracture) and biological complications (i.e., peri-implant mucositis [PM] and peri-implantitis) were identified from the patients' treatment records, clinical photographs, periapical radiographs, panoramic radiographs, and clinical indices. The correlations between complication rates and the following clinical factors were determined: gender, age, position in the jaw, placement location, functional duration, clinical crown-to-implant length ratio, crown height space, and the use of a submerged or nonsubmerged placement procedure. RESULTS. Mechanical and biological complications were present in 25 of 73 ISSCs with the modified LSP. LSL (n=11) and PM (n=11) were the most common complications. The incidence of mechanical complications was significantly related to gender (P=.018). The other clinical factors were not significantly associated with mechanical and biological complication rates. CONCLUSION. Within the limitations of this study, the incidence of mechanical and biological complications in the posterior region was similar for both modified LSP and conventional implant prosthetic systems. In addition, the modified LSP is amenable to maintenance care, which facilitates the prevention and treatment of mechanical and biological complications.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.3
• /
• pp.238-244
• /
• 2000

The present study was aimed to investigate the effect of osseointegration according to implant placement timing in the distracted alveolar bone using intraoral distraction device. Six adult mongrel dogs of either sex, weighing about 15kg, were used. The animals were divided into 4-week and 8-week groups according to the timing of implant installation. The left upper and lower premolars and first molars were extracted and an alveoloplasty was performed to simulate an atrophic ridge. After 12 weeks of healing, a segmental osteotomy was made and an intraoral distraction device which was designed for augmentation of vertical height of the edentulous ridge was applied. Latency period was allowed for 5 days and then distraction was made at a rate of 1.2mm/day for 8 days. Four or eight weeks after distraction, implants were installed. Twelve weeks after implant installation, the animals were sacrificed. Macroscopic, radiographic, and histologic examinations of distracted alveolar ridge were performed. No significant abnormalities such as infection and dehiscence of overlying soft tissue were observed. Radiographically, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in the both groups. The satisfactory osseointegration was achieved in the distracted gap of the both groups, but fibrous tissue appeared on the buccal side of implant in the distracted gap in 4-week group. These results suggest that proper timing of implant installation is 8 weeks rather than 4 weeks after distraction when dental implant is to be placed onto the distracted bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.28 no.4
• /
• pp.326-329
• /
• 2002

Adequate alveolar bone height and width are required for the successful placement of dental implants. Conventional therapeutic regimens for alveolar atrophy are bone grafts or augmentation using allografts and membrane (GBR). Conventional graft techniques have some limitations and complications such as infection, soft tissue problem and high resorption rate. Recently, distraction osteogenesis of alveolar bone is considered as a new alternative for ridge augmentation. Distraction osteogenesis was originally defined and popularized by Ilizarov for lengthening of long bone. Some clinicians have tried to apply distraction osteogenesis in treatment of maxillofacial discrepancies. It was also used to augment alveolar bone. Cologne study group successfully applied the technique for augmentation of alveolar bone and designed several miniplate-distractor systems fabricated by Martin Medizintechnik GmbH in Germany. Vertical distraction of alveolar bone was successfully completed in 104 patients with miniplate-distractor systems. The mean distance of distraction was 10.2mm (range: 6-15 mm) and the mean length of segment was 45 mm (range: 6-127 mm). 162 dental implants in 54 patients were placed immediately or 4 weeks later after removal of the distractor. The results of our study show that vertical distraction of alveolar bone is an effective and reliable technique to restore alveolar atrophy and alveolar vertical defect caused by trauma or tumor.

• Journal of Periodontal and Implant Science
• /
• v.47 no.1
• /
• pp.2-12
• /
• 2017

The aim of this narrative review is to describe treatment options for the posterior regions of the mandible and the maxilla, comparing short implants vs. longer implants in an augmented bone. The dental literature was screened for treatment options enabling the placement of dental implants in posterior sites with a reduced vertical bone height in the maxilla and the mandible. Short dental implants have been increasingly used recently, providing a number of advantages including reduced patient morbidity, shorter treatment time, and lower costs. In the posterior maxilla, sinus elevation procedures were for long considered to be the gold standard using various bone substitute materials and rendering high implant survival rates. More recently, implants were even placed without any further use of bone substitute materials, but the long-term outcomes have yet to be documented. Vertical bone augmentation procedures in the mandible require a relatively high level of surgical skill and allow the placement of standard-length dental implants by the use of autogenous bone blocks. Both treatment options, short dental implants, and standard-length implants in combination with vertical bone augmentation procedures, appear to result in predictable outcomes in terms of implant survival rates. According to recent clinical studies comparing the therapeutic options of short implants vs. long implants in augmented bone, the use of short dental implants leads to a number of advantages for the patients and the clinician.