• Journal of Periodontal and Implant Science
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• v.50 no.2
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• pp.97-105
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• 2020

Purpose: The present retrospective clinical study aimed to evaluate and compare the clinical and radiographic parameters, complications, and satisfaction in patients who received fixed prostheses supported by narrow-diameter implants (NDIs) in the anterior and posterior jaw. Methods: Patients aged ≥30 years who had NDI-supported fixed prostheses in the anterior or posterior region of either jaw for at least 2 years were included. Complications such as chipping of the crown; loosening or fracture of the screw, crown abutment, or implant; and loss of retention were recorded. Clinical peri-implant outcomes and crestal bone loss (CBL) were measured. A questionnaire was used to record responses regarding the aesthetics and function of the fixed restorations. Analysis of variance was used to assess the significance of between-group mean comparisons. The log-rank test was performed to analyze the influence of location and prosthesis type on technical complications. Results: Seventy-one patients (mean age: 39.6 years) provided informed consent with a mean follow-up duration of 53 months. Only bleeding on probing showed a statistically significant difference between NDIs in the anterior and posterior regions. The complication rate for NDIs in the posterior region was significantly higher than that for NDIs in the anterior region (P=0.041). For NDIs, CBL was significantly higher around splinted crowns than single crowns (P=0.022). Overall mean patient satisfaction was 10.34±3.65 on a visual analogue scale. Conclusions: NDIs in the anterior and posterior jaws functioned equally well in terms of periimplant soft and hard tissue health and offered acceptable patient satisfaction and reasonable complication rates.

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.396-404
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• 2016

Purpose: The aim of this retrospective study was to determine the association between dental implants in the posterior region and traumatic occlusion in the adjacent premolars, using data collected during from 2002 to 2015. Methods: Traumatic occlusion in the adjacent premolars was assessed by examining clinical parameters (bleeding on probing, probing pocket depth, fremitus, and tooth mobility) and radiographic parameters (loss of supporting bone and widening of the periodontal ligament space) over a mean follow-up of 5 years. Clinical factors (gender, age, implant type, maxillary or mandibular position, opposing teeth, and duration of functional loading) were evaluated statistically in order to characterize the relationship between implants in the posterior region and traumatic occlusion in the adjacent premolars. Results: The study inclusion criteria were met by 283 patients, who had received 347 implants in the posterior region. The incidence of traumatic occlusion in the adjacent premolars was significantly higher for splinted implants (P=0.004), implants in the maxillary region (P<0.001), and when implants were present in the opposing teeth (P<0.001). The other clinical factors of gender, age, and duration of functional loading were not significantly associated with traumatic occlusion. Conclusions: This study found that the risk of traumatic occlusion in the adjacent premolars increased when splinted implants were placed in the maxillary molar region and when the teeth opposing an implant also contained implants.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.399-406
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• 2013

Reports about the intrusion of a natural tooth bounded by implants are very rare, although some concerns have been discussed on the intrusion of teeth connected to implants. A female aged 56 years received an implant (mandibular right first premolar) and post/core onto root rest (mandibular right second premolar) and was restored by single zirconia crown, respectively. Molars were implant restorations. Four month after loading, second premolar was intruded and prominent gap was shown between opposite tooth. Because nonspecific discomfort was expressed, observation was decided after explanation of prognosis of tooth without treatment. Three month later reversal to original position was detected on the periapical radiographs and fully recovered position with intimate contact was completed 11 more months later. Till now 2 years and 3 month observation is being performed. Through the observation of spontaneous recovery of a natural tooth bounded by implants, the cause of intrusion and a mechanism of spontaneous recovery could be estimated.

• Imaging Science in Dentistry
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• v.47 no.3
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• pp.175-180
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• 2017

Purpose: Pineal gland calcification has been proposed to play a role in the pathogenesis of Alzheimer disease. This study evaluated the prevalence and extent of pineal gland calcification in cone-beam computed tomography (CBCT) scans of patients referred for dental implant therapy who could possibly be a vulnerable group for this condition. Materials and Methods: A retrospective evaluation of 500 CBCT scans was conducted. Scans that showed the area where the pineal gland was located were included. The scans were initially screened by a single observer to record the prevalence and extent of calcification. Six weeks following the completion of the study, another investigator randomly reviewed and selected 50 scans to investigate inter-observer variation, which was evaluated using reliability analysis statistics. The prevalence and measurements of the calcifications were reported using descriptive statistics. The chi-square test was used to compare the prevalence between males and females. Results: The prevalence of pineal gland calcification was 58.8%. There was no statistically significant correlation between age and the extent of the calcification. The prevalence of calcification was 58.6% in females and 59.0% in males. The average anteroposterior measurement was $3.73{\pm}1.63mm$, while the average mediolateral measurement was $3.47{\pm}1.31mm$. The average total calcified area was $9.79{\pm}7.59mm^2$. Conclusion: The prevalence of pineal gland calcification was high in patients undergoing implant therapy. While not all pineal gland calcifications lead to neurodegenerative disorders, they should be strongly considered in the presence of any symptoms as a reason to initiate further investigations.

• Journal of Powder Materials
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• v.12 no.5 s.52
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• pp.325-331
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• 2005

Implant prototypes with various porosities were fabricated by electro-discharge-sintering of atomized spherical Ti-6Al-4V powders. Single pulse of 0.75 to 2.0 kJ/0.7 g-powder, using 150, 300, and $450{\mu}F$ capacitors was applied to produce a fully porous and porous surfaced implant compact. The solid core formed in the center of the compact after discharge was composed of acicular ${\alpha}+{\beta}$ grains and porous layer consisted of particles connected in three dimensions by necks. The solid core and neck sizes increased with an increase in input energy and capacitance. On the other hand, pore volume decreased with increased capacitance and input energy due to the formation of solid core. Capacitance and input energy are the only controllable discharge parameters even though the heat generated during a discharge is the unique parameter that determines the porosity of compact. It is known that electro-discharge-sintering of spherical Ti-6Al-4V powders can efficiently produce fully-porous and porous surfaced Ti-6Al-4V implants with various porosities in a short time less then 400 isec by manipulating the discharging condition such as input energy and capacitance including powder size.

• Journal of Periodontal and Implant Science
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• v.53 no.3
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• pp.218-232
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• 2023

Purpose: This study evaluated the efficacy of a tube-shaped poly(ε) caprolactone - β tricalcium phosphate (PCL-TCP) scaffold with the incorporation of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) and platelet-rich plasma (PRP) for bone regeneration in the procedure of single-stage sinus augmentation and dental implantation in minipigs. Methods: Implants were placed in the bilateral sides of the maxillary sinuses of 5 minipigs and allocated to a PCL-TCP+hUCMSCs+PRP group (n=5), a PCL-TCP+PRP group (n=5), and a PCL-TCP-only group (n=6). After 12 weeks, bone regeneration was evaluated with soft X-rays, micro-computed tomography, fluorescence microscopy, and histomorphometric analysis. Results: Four implants failed (2 each in the PCL-TCP+hUCMSCs+PRP and PCLTCP+hUCMSC groups). An analysis of the grayscale levels and bone-implant contact ratio showed significantly higher mean values in the PCL-TCP+hUCMSCs+PRP than in the PCL-TCP group (P=0.045 and P=0.016, respectively). In fluoromicroscopic images, new bone formation around the outer surfaces of the scaffolds was observed in the PCLTCP+hUCMSCs+PRP group, suggesting a tenting effect of the specially designed scaffolds. Bone regeneration at the scaffold-implant interfaces was observed in all 3 groups. Conclusions: Using a tube-shaped, honeycombed PCL-TCP scaffold with hUCMSCs and PRP may serve to enhance bone formation and dental implants' osseointegration in the procedure of simultaneous sinus lifting and dental implantation.

• International Journal of Oral Biology
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• v.35 no.3
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• pp.129-135
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• 2010

Recent studies have implicated reactive oxygen species (ROS) as determinants of the pathological pain caused by the activation of peripheral neurons. It has not been elucidated, however, how ROS activate the primary sensory neurons in the pain pathway. In this study, calcium imaging was performed to investigate the effects of NaOCl, a ROS donor, on the intracellular calcium concentration ($[Ca^{2+}]i$) in acutely dissociated dorsal root ganglion (DRG) neurons. DRG was sequentially treated with 0.2 mg/ml of both protease and thermolysin, and single neurons were then obtained by mechanical dissociation. The administration of NaOCl then caused a reversible increase in the $[Ca^{2+}]i$, which was inhibited by pretreatment with phenyl-N-tertbuthylnitrone (PBN) and isoascorbate, both ROS scavengers. The NaOCl-induced $[Ca^{2+}]i$ increase was suppressed both in a calcium free solution and after depletion of the intracellular $Ca^{2+}$ pool by thapsigargin. Additionally, this increase was predominantly blocked by pretreatment with the transient receptor potential (TRP) antagonists, ruthenium red ($50\;{\mu}M$) and capsazepine ($10\;{\mu}M$). Collectively, these results suggest that an increase in the intracellular calcium concentration is produced from both extracellular fluid and the intracellular calcium store, and that TRP might be involved in the sensation of pain induced by ROS.

• Journal of Periodontal and Implant Science
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• v.41 no.5
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• pp.248-252
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• 2011

Purpose: The anterior region is a challenge for most clinicians to achieve optimal esthetics with dental implants. The provisional crown is a key factor in the success of obtaining pink esthetics around restorations with single implants, by soft tissue and inter-proximal papilla shaping. Provisional abutments bring additional costs and make the treatment more expensive. Since one of the aims of the clinician is to reduce costs and find more economic ways to raise patient satisfaction, this paper describes a practical method for chair-side fabrication of non-occlusal loaded provisional crowns used by the authors for several years successfully. Methods: Twenty two patients (9 males, 13 females; mean age, 36,72 years) with one missing anterior tooth were treated by using the presented method. Metal definitive abutments instead of provisional abutments were used and provisional crowns were fabricated on the definitive abutments for all of the patients. The marginal fit was finished on a laboratory analogue and temporarily cemented to the abutments. The marginal adaptation of the crowns was evaluated radiographically. Results: The patients were all satisfied with the final appearance and no complications occurred until the implants were loaded with permanent restorations. Conclusions: The use of the definitive abutments for provisional crowns instead of provisional abutments reduces the costs and the same results can be obtained.

• Archives of Plastic Surgery
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• v.33 no.2
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• pp.155-160
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• 2006

Although several reports have been introduced about dual plane augmentation mammaplasty, the description of periareolar approach dual plane augmentation mammaplasty was few. This article describes specific characteristics, and different classification and techniques for the periareolar dual plane breast augmentation while postoperative scars resulted from inframammary crease approach caused complaints. A total of 124 patients(248 breasts) had periareolar dual plane augmentation surgery from 1998 to 2004. Anatomic implants were used in 43 cases. Most of the patients were satisfied with the outcomes of periareolar dual plane augmentation. Periareolar dual plane augmentation mammaplasty adjusts implant and tissue relationships to ensure adequate soft-tissue coverage while optimizing implant-breast parenchymal dynamics to offer increased benefits and fewer faults compared to a single pocket location in a wide range of breast types with minimal scars. Two types of dual plane classifications are discussed in this study for the periareolar approach exclusively. The boundaries of retroglandular dissection remain constant, as the costal origin of pectoralis major are divided. Type A dual plane implies that the inferior edge of pectoralis muscle lies below the inferior areolar border, and type B dual plane implies that the inferior edge lies above the superior areolar border.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.5
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• pp.353-357
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• 2020

Fractures of the orbital floor and walls are among the most frequent maxillofacial fractures. Virtual three-dimensional (3D) planning and use of patient-specific implants (PSIs) could improve anatomic and functional outcomes in orbital reconstruction surgery. The presented case was a victim of a terrorist attack involving improvised explosive devices. This 58-year-old female suffered severe wounds caused by a single piece of metal from a bomb, shattering the left orbital floor and lateral orbital wall. Due to remaining hypotropia of the left eye compared to the right eye, late orbital floor reconstruction was carried out with a personalised 3D printed titanium implant. We concluded that this technique with PSI appears to be a viable method to correct complex orbital floor defects. Our research group noted good aesthetic and functional results one year after surgery. Due to the complexity of the surgery for a major bony defect of the orbital floor, it is important that the surgery be executed by experienced surgeons in the field of maxillofacial traumatology.