• The Journal of Advanced Prosthodontics
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• v.8 no.2
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• pp.150-157
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• 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 Periodontal and Implant Science
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• v.53 no.5
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• pp.376-387
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• 2023

Purpose: Peri-implantitis (PI) is an inflammatory condition associated with the destruction of bone tissue around a dental implant, and diode lasers can be used to treat this disease. In this study, we aimed to evaluate the effectiveness of a 940-nm diode laser for the nonsurgical treatment of PI. Methods: Twenty patients (8 women and 12 men) were enrolled in a split-mouth randomized controlled study. In the control group (CG), mechanical debridement with titanium curettes accompanied by airflow was performed around the implants. The test group (TG) was treated similarly, but with the use of a diode laser. Clinical measurements (plaque index, gingival index [GI], probing pocket depth [PPD], bleeding on probing [BOP], clinical attachment level, and interleukin-1β [IL-1β] in the peri-implant crevicular fluid) were evaluated and recorded at baseline and 3 months. IL-1β levels were determined using the enzyme-linked immunosorbent assay method. Results: The symptoms were alleviated in both groups at 3 months as assessed through clinical measurements. GI, BOP, and PPD were significantly lower in the TG than in the CG (P<0.05). The IL-1β level increased post-treatment in both groups, but this increase was only statistically significant (P<0.05) in the CG. Conclusions: The diode laser enabled improvements in clinical parameters in the periimplant tissue. However, it did not reduce IL-1β levels after treatment. Further studies about the use of diode lasers in the treatment of PI will be necessary to evaluate the effects of diode lasers in PI treatment.

• Journal of Periodontal and Implant Science
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• v.52 no.6
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• pp.509-521
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• 2022

Purpose: Systemic health has a profound effect on dental treatment. The aim of this study was to evaluate peri-implant bone loss and health screening data to discover factors that may influence peri-implant diseases. Methods: This study analyzed the panoramic X-rays of patients undergoing health screenings at the Health Promotion Center at Seoul St. Mary's Hospital in 2018, to investigate the relationship between laboratory test results and dental data. The patients' physical data, such as height, weight, blood pressure, hematological and urine analysis data, smoking habits, number of remaining teeth, alveolar bone level, number of implants, and degree of bone loss around the implant, were analyzed for correlations. Their associations with glycated hemoglobin, glucose, blood urea nitrogen (BUN), creatinine, and severity of periodontitis were evaluated using univariate and multivariate regression analysis. Results: In total, 2,264 patients opted in for dental health examinations, of whom 752 (33.2%) had undergone dental implant treatment. These 752 patients had a total of 2,658 implants, and 129 (17.1%) had 1 or more implants with peri-implant bone loss of 2 mm or more. The number of these implants was 204 (7%). Body mass index and smoking were not correlated with peri-implant bone loss. Stepwise multivariate regression analysis revealed that the severity of periodontal bone loss (moderate bone loss: odds ratio [OR], 3.154; 95% confidence interval [CI], 1.175-8.475 and severe bone loss: OR, 7.751; 95% CI, 3.003-20) and BUN (OR, 1.082; 95% CI, 1.027-1.141) showed statistically significant predictive value. The severity of periodontitis showed greater predictive value than the biochemical parameters of blood glucose, renal function, and liver function. Conclusions: The results of this study showed that periodontal bone loss was a predictor of peri-implant bone loss, suggesting that periodontal disease should be controlled before dental treatment. Diligent maintenance care is recommended for patients with moderate to severe periodontal bone loss.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.4
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• pp.458-467
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• 2016

Cement-retained implant prosthesis has several advantages in the esthetic and occlusal aspects. However, the difficulty of the retrievability and the possibility of peri-implantitis induced by the cement excess would be a threatening factor to the implant prognosis. Peri-implantitis resulting from the remaining cement could occur later on to the patients with periodontitis history. Retention can be controlled by selecting the right cement type. Retention of the cement was the strongest in the resin cement, followed by resin modified glass ionomer cement, poIycarboxylate cement, zinc phosphate cement and glass ionomer cement. Retention of the provisional cement weakened after thermocycling. Other factors such as the abutment number, abutment alignment, height and taper of the abutment can also affect the total retention. To the success of the cement-retained prosthesis, it's important to select the right cement for the clinical purpose. The prosthesis should be fabricated in accordance with the biomechanical requirements. The prosthesis should be cemented with the techniques to reduce the excess cement as much as possible. In addition, the excess cement should be identified using the radiography and carefully removed.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.749-763
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• 2001

Osseointegrated titanium implants have become an integral therapy for the replacement of teeth lost. For dental implant materials, titanium, hydroxyapatite and alumina oxide have been used, which of them, titanium implants are in wide use today. Titanium is known for its high corrosion resistance and biocompatability, because of the high stability of oxide layer mainly consists of $TiO_2$. With the development of peri-implantitis, the implant surface is changed in surface topography and element composition. None of the treatments for cleaning and detoxification of implant surface is efficient to remove surface contamination from contaminated titanium implants to such extent that the original surface elemental composition. In this sights, the purpose of this study was to evaluate rough surface titanium implants by means of scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS) with respect to surface appearance and surface elemental composition. Moreover, it was also the aim to get the base for treatments of peri-implantitis. For the SEM and XPS study, rough surface titanium models were fabricated for control group. Six experimental groups were evaluated: 1) long-time room exposure, 2 ) air-powder abrasive cleaning for 1min, 3) burnishing in citric acid(pH1) for 1min, 4) burnishing in citric acid for 3min, 5) burnishing in tetracycline for 1min, 6) burnishing in tetracycline for 3min. All experimental treatments were followed by 1min of rinsing with distilled water. The results were as follows: 1. SEM observations of all experimental groups showed that any changes in surface topography were not detected when compared with control group. (750 X magnification) 2. XPS analysis showed that in all experimental groups, titanium and oxygen were increased and carbon was decreased, when compared with control group. 3. XPS analysis showed that the level of titanium, oxygen and carbon in the experimental group 3(citric acid treatment for 1min, followed by 1min of distilled water irrigation) reached to the level of control group. 4. XPS analysis showed that significant differences were not detected between the experimental group 1 and the other experimental groups except of experimental group 3. The Ti. level of experimental group 2, airpowder abrasive treatment for lmin followed by 1min of saline irrigation, was lower than the Ti. level of tetracycline treated groups, experimental group 5 and 6. From the result of this study, it may be concluded that the 1min of citric acid treatment followed by same time of rinsing with distilled water gave the best results from elemental points of view, and can be used safely to treat peri-implantitis.

• Journal of dental hygiene science
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• v.17 no.2
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• pp.175-182
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• 2017

From March 1, 2016 to August 31, 2016, 375 dental implant patients between the ages of 30 and 70 years to evaluate their subjective symptoms and satisfaction according to prosthesis methods. The collected data were analyzed using the chi-square distribution test, t-test, one-way analysis of variance, and multiple logistic regression. Of the patients with subjective symptoms of peri-implantitis, 40.5% reported food impaction, 49.1% reported bleeding, 61.1% reported pain, 61.9% reported halitosis, and the overall satisfaction level with the implants was 3.95 points. In the prosthesis methods, implant-teeth connective group showed the lowest level of the food impaction (21.3%), the pain (35.5%), and the halitosis (36.6%) (p<0.001), and the lowest bleeding was the implant single (33.8%) (p<0.05). Patient satisfaction was higher in the implant-teeth connective group (4.06 points) and the group without bone grafting (4.03 points) (p<0.01). Factor analysis showed that implant satisfaction was 0.43 times lower in the single implant group and 0.44 times lower in the implant-implant connective group than in the implant-teeth connective group. As a result of the study, it is expected that the method of extending the life of adjacent teeth and restoring the function of the tooth defect region is an implant-teeth connection method, so that it can be utilized positively through various clinical studies.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.133-139
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• 2020

Purpose: This study compared 2 cone-beam computed tomography (CBCT) systems in the detection of mechanically simulated peri-implant buccal bone defects in dry human mandibles. Materials and Methods: Twenty-four implants were placed in 7 dry human mandibles. Peri-implant bone defects were created in the buccal plates of 16 implants using spherical burs. All mandibles were scanned using 2 CBCT systems with their commonly used acquisition protocols: i-CAT Gendex CB-500 (Imaging Sciences, Hatfield, PA, USA; field of view [FOV], 8 cm×8 cm; voxel size, 0.125 mm; 120 kVp; 5 mA; 23 s) and Orthopantomograph OP300 (Intrumentarium, Tuusula, Finland; FOV, 6 cm×8 cm; voxel size, 0.085 mm; 90 kVp; 6.3 mA; 13 s). Two oral and maxillofacial radiologists assessed the CBCT images for the presence of a defect and measured the depth of the bone defects. Diagnostic performance was compared in terms of the area under the curve (AUC), accuracy, sensitivity, specificity, and intraclass correlation coefficient. Results: High intraobserver and interobserver agreement was found (P<0.05). The OP300 showed slightly better diagnostic performance and higher detection rates than the CB-500 (AUC, 0.56±0.03), with a mean accuracy of 75.0%, sensitivity of 81.2%, and specificity of 62.5%. Higher contrast was observed with the CB-500, whereas the OP300 formed more artifacts. Conclusion: Within the limitations of this study, the present results suggest that the choice of CBCT systems with their respective commonly used acquisition protocols does not significantly affect diagnostic performance in detecting and measuring buccal peri-implant bone loss.

• Journal of Periodontal and Implant Science
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• v.48 no.2
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• pp.84-91
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• 2018

Purpose: The purpose of this study was to visualize and identify peri-implant bone defects in optical coherence tomography (OCT) images and to obtain quantitative measurements of the defect depth. Methods: Dehiscence defects were intentionally formed in porcine mandibles and implants were simultaneously placed without flap elevation. Only the threads of the fixture could be seen at the bone defect site in the OCT images, so the depth of the peri-implant bone defect could be measured through the length of the visible threads. To analyze the reliability of the OCT measurements, the flaps were elevated and the depth of the dehiscence defects was measured with a digital caliper. Results: The average defect depth measured by a digital caliper was $4.88{\pm}1.28mm$, and the corresponding OCT measurement was $5.11{\pm}1.33mm$. Very thin bone areas that were sufficiently transparent in the coronal portion were penetrated by the optical beam in OCT imaging and regarded as bone loss. The intraclass correlation coefficient between the 2 methods was high, with a 95% confidence interval (CI) close to 1. In the Bland-Altman analysis, most measured values were within the threshold of the 95% CI, suggesting close agreement of the OCT measurements with the caliper measurements. Conclusions: OCT images can be used to visualize the peri-implant bone level and to identify bone defects. The potential of quantitative non-invasive measurements of the amount of bone loss was also confirmed.

• The Journal of the Korean dental association
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• v.53 no.9
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• pp.618-627
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• 2015

Purpose : The purpose of this clinical study was to evaluate the effect of chelating and deproteinizing agent containing dental conditioning gel on alleviation of peri-implant mucosa inflammation. Methods: 36 patients with functionally loaded implants for at least 1 year and have clinical signs of peri-implant mucositis were recruited. At baseline, all implants received subgingival prophylaxis with ultrasonic scaler. In the test group, patients were provided a chelating and deproteinizing agent dental conditioning gel (Clinplant$^{(R)}$) and were given instructions to applicate it around the implants using an interdental brush for 2 weeks. Chlorhexidine and saline were provided to the positive control group and negative control group, respectively. The modified sulcus bleeding index (mSBI), modified plaque index (mPI), and probing pocket depth (PPD) were evaluated at baseline, 1 week, and 2 weeks. Results: In the Clinplant$^{(R)}$ and chlorhexidine group, mSBI (-0.81, -0.85 respectively; p<0.01), mPI (-0.46, -0.5 respectively; p<0.01), and PPD (-0.58, -0.48 respectively; p<0.01) at 2 weeks were significantly reduced from baseline. In the saline group, all the clinical parameters were reduced but there was no statistical significance. The saline may be attributed to the influence of prophylaxis at baseline. Conclusions: The present study demonstrated the beneficial clinical effects of chelating and deproteinizing agent containing dental conditioning gel to decrease peri-implant mucosa inflammation equivalent to chlorhexidine. This dental conditioning gel might be useful for alleviation of peri-implant mucosa inflammation.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.575-584
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• 2007

The present study was performed to evaluate the effect of citric acid on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface, and HA coated surface were utilized. Pure titanium machined surface and HA coated surface were rubbed with pH 1 citric acid for 30s., 45s., 60s., 90s., and 120s. respectively. Then, the specimens were processed for scanning electron microscopic observation. The following results were obtained. 1. The specimens showed a few shallow grooves and ridges in pure titanium machined surface implants. The roughness of surfaces conditioned with pH 1 citric acid was slightly increased. 2. In HA-coated surfaces, round particles were deposited irregularly. The specimens were not significant differences within 45s. But, began to be changed from 60s. The roughness of surfaces was lessened and the surface dissolution was increased relative to the application time. In conclusion, pure titanium machined surface implants and HA coated surface implants can be treated with pH 1 citric acid for peri-implantitis treatment if the detoxification of these surfaces could be evaluated.