Marginal bone loss between internal- and external- abutment connection type implants placed in the first molar area

Purpose@#The purpose of this study was to investigate the effect of implant connection type on marginal bone loss (MBL) and to ana-lyze the factors that affect MBL. This study focuses on single implants planted in the upper and lower first molar area. @*Materials and Methods@#A total of 87 implants from 68 patients were tracked for a period over 5 years. There were 57 external connection type (EC) implants and 30 internal connection type (IC) implants in 38 males and 30 females. The MBL and EA were measured from intraoral radiograph images taken after 5 years at most. @*Results@#Significant difference in MBL between EC and IC type was observed in pa-tients without GBR or diabetes. Patients without GBR exhibited an MBL of -0.065 ± 0.859 mm in EC type and -0.627 ± 0.639 mm in IC type (P = 0.025). Using multiple regression analysis, a statistically significant negative correlation was observed between MBL and conditions including implant-abutment connection type (β = -0.303), diabetes (β = -0.113), emergence angle > 30° (β = -0.234), and age (β = -0.776). @*Conclusion@#Within this results, IC type implants had less MBL than EC type, and implant prosthesis with emergence angle over 30° showed greater MBL. To minimize the MBL of the implant and ensure implant stability, careful consideration should be given to the EA of implant prosthesis and its connection type.

Isolation of High Purity Mouse Mesenchymal Stem Cells through Depleting Macrophages Using Liposomal Clodronate

BACKGROUND@#The use of mouse bone marrow mesenchymal stem cells (mBMSCs) represents a promising strategy for performing preclinical studies in the field of cell-based regenerative medicine; however, mBMSCs obtained via conventional isolation methods have two drawbacks, i.e., (i) they are heterogeneous due to frequent macrophage contamination, and (ii) they require long-term culturing for expansion. @*METHODS@#In the present study, we report a novel strategy to generate highly pure mBMSCs using liposomal clodronate.This approach is based on the properties of the two cell populations, i.e., BMSCs (to adhere to the plasticware in culture dishes) and macrophages (to phagocytose liposomes). @*RESULTS@#Liposomal clodronate added during the first passage of whole bone marrow culture was selectively engulfed by macrophages in the heterogeneous cell population, resulting in their effective elimination without affecting the MSCs.This method allowed the generation of numerous high-purity Sca-1 ＋ CD44 ＋ F4/80 - mBMSCs ([ 95%) with just one passaging. Comparative studies with mBMSCs obtained using conventional methods revealed that the mBMSCs obtained in the present study had remarkably improved experimental utilities, as demonstrated by in vitro multilineage differentiation and in vivo ectopic bone formation assays. @*CONCLUSION@#Our newly developed method, which enables the isolation of mBMSCs using simple and convenient protocol, will aid preclinical studies based on the use of MSCs.

Radiologic evaluation and survival rate of taper-straight designed implant with SLA surface: A 1-year follow-up retrospective study / 대한치과보철학회지

Purpose@#This study was conducted to evaluate clinical usefulness by evaluating the marginal bone resorption and survival rate of an implant with a taper straight type SLA surface domestically available on the market recently. @*Materials and methods@#40 implants satisfying the including criteria were observed for one year of 125 implants of 83 adult men and women who had KISPLANT® implanted from August 2016 to December 2019 at the Department of Periodontology, Chonnam National University Dental Hospital. The marginal bone level was measured on periapical radiographs taken initially and 1 year later and we analyzed implant survival and success rates. A t-test was used for the analysis of the association between the marginal bone resorption and the severity of periodontitis, supportive periodontal therapy, the inserted site, the cause of extraction, immediate placement, and systemic disease. @*Results@#After 1 year of loading, the mesial bone resorption was 0.74 ± 1.07 mm, and the distal bone resorption was 0.53 ± 1.04 mm. The marginal bone resorption of 2 mm or more occurred at 3 implants out of 40 implants after 1 year, so the success rate of implant was 92.5% and survival rate was 100%. There was a significant difference in mesial marginal bone resorption according to the inserted site and no significant differences were found between marginal bone resorption and the other factors. @*Conclusion@#As a result of marginal bone resorption, success rate, and survival rate in this study, we found little marginal bone resorption and high survival and success rate. It can be concluded that they represent excellent clinical results.

Low serum 25-hydroxyvitamin D levels, tooth loss, and the prevalence of severe periodontitis in Koreans aged 50 years and older

Purpose@#Vitamin D deficiency may cause bone loss and increased inflammation, which are well-known symptoms of periodontal disease. This study investigated whether serum 25-hydroxyvitamin D (25(OH)D) levels are associated with periodontal disease status and tooth loss. @*Methods@#Cross-sectional data from 5,405 individuals aged ≥50 years (2,253 males and 3,152 females) were obtained from the 2008–2010 Dong-gu study, a prospective cohort study of risk factors for chronic diseases. Periodontal examinations were conducted to evaluate the number of remaining teeth, the periodontal probing depth (PPD), the clinical attachment level (CAL), and bleeding on probing. The percentages of sites with PPD ≥4 mm and CAL ≥4 mm were recorded for each participant. The severity of periodontitis was classified using the Centers for Disease Control and Prevention and the American Academy of Periodontology case definitions.Serum 25(OH)D levels were classified as reflecting severe deficiency, deficiency, insufficiency, or sufficiency. Multivariate linear regression analysis was performed to assess the associations of serum 25(OH)D levels with periodontal parameters and the number of remaining teeth after adjusting for confounders including age, smoking status, alcohol consumption status, month of blood collection, and physical activity. Multivariate logistic regression was used to evaluate the association between serum vitamin D levels and severe periodontitis. An overall statistical analysis and a stratified analysis by sex were performed. @*Results@#Overall, the rates of severe deficiency, deficiency, insufficiency, and sufficiency were 6.5%, 67.9%, 22.4%, and 3.2%, respectively. After adjustment for confounders, vitamin D levels were directly associated with the number of remaining teeth, an association that was significant in males, but not in females. Sufficient serum 25(OH)D was associated with a low frequency of severe periodontitis. @*Conclusions@#This population-based cross-sectional study indicates that low serum 25(OH) D is significantly associated with tooth loss and severe periodontitis in Koreans aged 50 years and older.

Low serum 25-hydroxyvitamin D levels, tooth loss, and the prevalence of severe periodontitis in Koreans aged 50 years and older

Purpose@#Vitamin D deficiency may cause bone loss and increased inflammation, which are well-known symptoms of periodontal disease. This study investigated whether serum 25-hydroxyvitamin D (25(OH)D) levels are associated with periodontal disease status and tooth loss. @*Methods@#Cross-sectional data from 5,405 individuals aged ≥50 years (2,253 males and 3,152 females) were obtained from the 2008–2010 Dong-gu study, a prospective cohort study of risk factors for chronic diseases. Periodontal examinations were conducted to evaluate the number of remaining teeth, the periodontal probing depth (PPD), the clinical attachment level (CAL), and bleeding on probing. The percentages of sites with PPD ≥4 mm and CAL ≥4 mm were recorded for each participant. The severity of periodontitis was classified using the Centers for Disease Control and Prevention and the American Academy of Periodontology case definitions.Serum 25(OH)D levels were classified as reflecting severe deficiency, deficiency, insufficiency, or sufficiency. Multivariate linear regression analysis was performed to assess the associations of serum 25(OH)D levels with periodontal parameters and the number of remaining teeth after adjusting for confounders including age, smoking status, alcohol consumption status, month of blood collection, and physical activity. Multivariate logistic regression was used to evaluate the association between serum vitamin D levels and severe periodontitis. An overall statistical analysis and a stratified analysis by sex were performed. @*Results@#Overall, the rates of severe deficiency, deficiency, insufficiency, and sufficiency were 6.5%, 67.9%, 22.4%, and 3.2%, respectively. After adjustment for confounders, vitamin D levels were directly associated with the number of remaining teeth, an association that was significant in males, but not in females. Sufficient serum 25(OH)D was associated with a low frequency of severe periodontitis. @*Conclusions@#This population-based cross-sectional study indicates that low serum 25(OH) D is significantly associated with tooth loss and severe periodontitis in Koreans aged 50 years and older.

Analysis of esthetic factors and evaluation of esthetic perception for maxillary anteriors of dental students / 대한치과보철학회지

PURPOSE: This research is to investigate factors that affect dental aesthetics and analyze whether individual perception affects and difference of genders affects the esthetic factors. MATERIALS AND METHODS: Seventy dental students of Chonnam University aged from 25 to 35 years old without periodontal problems were included. Maxillary dental cast for participants were made, and standardized photo was taken with a digital camera. Maximum visual width and the position of gingival zenith of maxillary anterior teeth and maximum height of the maxillary central incisors were measured by a measurement program and the shape of central incisor was categorized. Questionnaire was conducted to evaluate esthetic perception. SPSS program was used to perform statistical analysis. RESULTS: The average visual width ratio of right maxillary anteriors was 1.38:1:0.78 and 1.41:1:0.81 for the left which differ from the golden ratio. The width to height ratio for right and left central incisor was 0.84 and 0.83 respectively. The gingival zenith position was determined to be: mostly, central incisors and canines were located in the distal side, lateral incisors were located in the center. The visual width ratio of right maxillary anterior teeth, ratio of width to height of central incisor, gingival zenith position, crown morphology and amounts of gingival exposure upon smiling were not significantly different between genders, and facial patterns and these dental esthetic factors were not related to aesthetic perception. CONCLUSION: Even though participants had the visual width ratio of maxillary anteriors or ideal width to ideal height of central incisors that did not agree with the golden ratio, they had high satisfaction for dental esthetics. Esthetic perception depends more on subjective judgements of participants than objective indices.

Humoral immune responses to periodontal pathogens in the elderly

PURPOSE: Elderly people are thought to be more susceptible to periodontal disease due to reduced immune function associated with aging. However, little information is available on the nature of immune responses against putative periodontal pathogens in geriatric patients. The purpose of this study was to evaluate the serum IgG antibody responses to six periodontal pathogens in geriatric subjects. METHODS: The study population consisted of 85 geriatric patients and was divided into three groups: 29 mild (MCP), 27 moderate (MoCP) and 29 severe (SCP) chronic periodontitis patients. Serum levels of IgG antibody to Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Prevotella intermedia were measured by enzyme-linked immunosorbent assay (ELISA) and compared among the groups. RESULTS: All three groups showed levels of serum IgG in response to P. gingivalis, A. actinomycetemcomitans, and P. intermedia that were three to four times higher than levels of IgG to T. forsythia, T. denticola, and F. nucleatum. There were no significant differences among all three groups in IgG response to P. gingivalis (P=0.065), T. forsythia (P=0.057), T. denticola (P=0.1), and P. intermedia (P=0.167), although the IgG levels tended to be higher in patients with SCP than in those with MCP or MoCP (with the exception of those for P. intermedia). In contrast, there were significant differences among the groups in IgG levels in response to F. nucleatum (P=0.001) and A. actinomycetemcomitans (P=0.003). IgG levels to A. actinomycetemcomitans were higher in patients with MCP than in those with MoCP or SCP. CONCLUSIONS: When IgG levels were compared among three periodontal disease groups, only IgG levels to F. nucleatum significantly increased with the severity of disease. On the contrary, IgG levels to A. actinomycetemcomitans decreased significantly in patients with SCP compared to those with MCP. There were no significant differences in the IgG levels for P. gingivalis, T. forsythia, T. denticola, and P. intermedia among geriatric patients with chronic periodontitis.

Quantitative analysis of periodontal pathogens present in the saliva of geriatric subjects

PURPOSE: At present, information regarding periodontal disease in geriatric patients is scarce. The purpose of this study was to quantify the periodontal pathogens present in the saliva of Korean geriatric patients and assess the relationship between the bacterial levels and the periodontal condition. METHODS: Six putative periodontal pathogens were quantified by using a real-time polymerase chain reaction assay in geriatric patient groups (>60 years) with mild chronic periodontitis (MCP), moderate chronic periodontitis (MoCP), and severe chronic periodontitis (SCP). The copy numbers of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Prevotella intermedia were measured. RESULTS: It was found that the bacterial copy numbers increased as the severity of the disease increased from MCP to SCP, except for P. intermedia. For P. intermedia, it was found that samples in the MCP group yielded the largest amount. It was also found that the quantities of P. gingivalis, T. forsythia, and T. denticola, the so-called "red complex" bacteria, were lower than those of F. nucleatum, A. actinomycetemcomitans, and P. intermedia in all of the samples. CONCLUSIONS: Collectively, the results of this study suggest that the levels of P. gingivalis, T. forsythia, F. nucleatum, and T. denticola present in saliva are associated with the severity of periodontal disease in geriatric patients.

Comparison of biofilm on titanium and zirconia surfaces: in vivo study / 대한치과보철학회지

PURPOSE: This study was conducted to compare in vivo biofilm formation on titanium surface and zirconia surface. MATERIALS AND METHODS: For biofilm formation on titanium and zirconia in oral cavity, after producing oral appliances using acrylic resin and orthodontic wire tailored to 9 subjects, we made titanium and zirconia specimens (6 mm x 6 mm x 2 mm), fixed them on oral appliances and maintained them in oral cavity of test subjects for 24 and 72 hours. Test subjects who have equipped two pairs of specimens maintained oral hygiene not by using toothpaste but only by tooth brushing. After 24 and 72 hours, we removed and observed specimens through scanning electron microscopy (SEM). RESULTS: Biofilm formation showed large deviation depending on individuals. For formation comparison between titanium and zirconia for 24 hours, zirconia showed less biofilm formation than titanium. Biofilm formation showed large deviation depending on individuals. As for formation comparison between zirconia and titanium, the degree of biofilm formation in zirconia was less than it was in titanium after a lapse of 24 hours. The result of biofilm formation in 72 hours trial show that zirconia has an inclination to formate less biofilm than it was in titanium. CONCLUSION: Based on the above results, we can conclude that early biofilm formation in oral cavity was influenced by difference of abutment materials.

Surface characteristics and osteoblastic cell response of alkali-and heat-treated titanium-8tantalum-3niobium alloy

PURPOSE: The aim of the present study was to evaluate the biological response of alkali- and heat-treated titanium-8tantalum-3niobium surfaces by cell proliferation and alkaline phosphatase (ALP) activity analysis. METHODS: Commercial pure titanium (group cp-Ti) and alkali- and heat-treated titanium-8tantalum-3niobium (group AHT) disks were prepared. The surface properties were evaluated using scanning electron microscopy, energy dispersed spectroscopy and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy and a profilometer. The contact angle and surface energy were also analyzed. The biological response of fetal rat calvarial cells on group AHT was assessed by cell proliferation and ALP activity. RESULTS: Group AHT showed a flake-like morphology microprofile and dense structure. XPS analysis of group AHT showed an increased amount of oxygen in the basic hydroxyl residue of titanium hydroxide groups compared with group cp-Ti. The surface roughness (Ra) measured by a profilometer showed no significant difference (P>0.05). Group AHT showed a lower contact angle and higher surface energy than group cp-Ti. Cell proliferation on group AHT surfaces was significantly higher than on group cp-Ti surfaces (P<0.05). In comparison to group cp-Ti, group AHT enhanced ALP activity (P<0.05). CONCLUSIONS: These results suggest that group AHT stimulates osteoblast differentiation.

Surface characteristics of thermally treated titanium surfaces

PURPOSE: The characteristics of oxidized titanium (Ti) surfaces varied according to treatment conditions such as duration time and temperature. Thermal oxidation can change Ti surface characteristics, which affect many cellular responses such as cell adhesion, proliferation, and differentiation. Thus, this study was conducted to evaluate the surface characteristics and cell response of thermally treated Ti surfaces. METHODS: The samples were divided into 4 groups. Control: machined smooth titanium (Ti-S) was untreated. Group I: Ti-S was treated in a furnace at 300degrees C for 30 minutes. Group II: Ti-S was treated at 500degrees C for 30 minutes. Group III: Ti-S was treated at 750degrees C for 30 minutes. A scanning electron microscope, atomic force microscope, and X-ray diffraction were used to assess surface characteristics and chemical composition. The water contact angle and surface energy were measured to assess physical properties. RESULTS: The titanium dioxide (TiO2) thickness increased as the treatment temperature increased. Additional peaks belonging to rutile TiO2 were only found in group III. The contact angle in group III was significantly lower than any of the other groups. The surface energy significantly increased as the treatment temperature increased, especially in group III. In the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, after 24 hours of incubation, the assessment of cell viability showed that the optical density of the control had a higher tendency than any other group, but there was no significant difference. However, the alkaline phosphatase activity increased as the temperature increased, especially in group III. CONCLUSIONS: Consequently, the surface characteristics and biocompatibility increased as the temperature increased. This indicates that surface modification by thermal treatment could be another useful method for medical and dental implants.

Antioxidant profile of whole saliva after scaling and root planing in periodontal disease

PURPOSE: This study compared the total antioxidant status (TAS) and superoxide dismutase (SOD) activity in the saliva of periodontally compromised patients before and after scaling and root planing (SRP) to assess their diagnostic utility. METHODS: Severe chronic periodontitis patient (test group) and subjects with no attachment loss, sites showing a 3 mm or more probing depth and a sulcus bleeding index < 10% (control group) were enrolled in this study. Saliva sampling and clinical examination were performed at one week, one month and 3 months after SRP. The TAS and SOD activity in each patient's saliva was measured for the comparative analysis between the groups. RESULTS: In the test group, the TAS decreased directly after SRP. With time, it increased slightly and was relatively unchanged compared to the baseline. In the control group, the TAS also decreased immediately after SRP but increased gradually with time until 3 months. The SOD activity in the test and control subjects decreased immediately after SRP until 1 month. At 3 months, the SOD activity had increased. Both groups had a similar profile of SOD activity. However, the SOD activity of the control group was significantly higher than that of the test group at each point in time (P < 0.05). CONCLUSIONS: There was a significant difference in the total salivary antioxidant level between the periodontitis and healthy or gingivitis (control) group during the experiment period. The total antioxidant level in the saliva was higher in the patients with severe chronic periodontitis than the healthy or gingivitis control before SRP. The SOD activity of the periodontitis patients was lower than the control at each time point. These findings conclusively reveal the possible use of saliva as a diagnostic tool for periodontal health.

MMP-1 promoter polymorphism in Korean with generalized aggressive periodontitis / 대한치주과학회지

PURPOSE: The aim of this study was to investigate matrix metalloproteinase 1 (MMP-1) gene polymorphism (1G/2G at -1607 and A/G at -519) in Korean subject and to assess the association between polymorphism and periodontal status. METHODS: Forty nine generalized aggressive periodontitis (GAP) patients and 57 periodontally healthy children were recruited and genomic DNA was extracted from buccal swab. The polymorphisms of MMP-1 promoter genes were determined by polymerase chain reaction and restriction fragment length product (PCR-RFLP) method. The distribution of genotype and allele frequency was compared between 2 groups by chi-square test. RESULTS: There was a significant difference in the distribution of genotypes and frequency of alleles between the GAP and reference groups at the position - 519 of MMP-1 gene promoter (P< 0.05). Allele G carrier rate was significantly lower in GAP group than that of the reference group (P< 0.001). At the position -1607 of MMP-1 gene promoter, genotype distribution and allele frequency showed no statistically significant difference between the groups. However, in the female group, a significant difference was observed between the groups for the genotype distribution, allele frequency and allele 1G carrier rate (P< 0.05). CONCLUSIONS: The DNA polymorphism at the MMP-1 gene promoter might be associated with GAP in Korean.

The clinical effects of modified full-mouth disinfection in the treatment of moderate to severe chronic periodontitis patients / 대한치주과학회지

PURPOSE: Full-mouth disinfection enables to reduce the probability of cross contamination from untreated pockets to treated ones, for completing the entire SRP under local anesthesia with chlorhexidine as a mouth wash in two visits within 24 hours. This study aimed to compare the clinical effects of modified full-mouth disinfection (Fdis) after 6 months with those of conventional SRP (cSRP). METHODS: Thirty non-smoking chronic periodontitis subjects were randomly allocated two groups. The Fdis group underwent the entire SRP under local anesthesia in two visits within 24 hours, a week after receiving supragingival scaling. A chlorhexidine (0.1%) solution was used for rinsing and subgingival irrigation for Fdis. The cSRP group received SRP per quadrant under local anesthesia at one-week intervals, one week after they had received scaling. Clinical parameters were recorded at baseline, after 1, 3 and 6 months. RESULTS: There are significant (P< 0.05) decreases in the sulcus bleeding index, and plaque index, and the increases in gingival recession were significantly smaller with Fdis after six months compared with cSRP. There was significant improvement in the probing depth and clinical attachment level for initially medium-deep pockets (4-6mm) after Fdis compared with cSRP. Multi-rooted teeth showed significantly larger attachment gain up to six months after Fdis. Single-rooted teeth showed significantly more attachment gain, 1 and 6 months after Fdis. CONCLUSIONS: Fdis has more beneficial effects on reducing gingival inflammation, plaque level, probing depth, gingival recession and improving clinical attachment level over cSRP.

IL-6 gene promoter polymorphisms in Korean generalized aggressive periodontitis / 대한치주과학회지

PURPOSE: The purpose of this study was to investigate the association of generalized aggressive periodontitis with IL-6 promoter gene single nucleotide polymorphisms(SNP). MATERIAL AND METHODS: The study population consisted of 52 generalized aggressive periodontitis patients(GAP) and 30 periodontally healthy control subjects, who were systemically healthy non-smokers. Genomic DNA was obtained from buccal swab. The IL-6 promotor SNP at the positions of -597, -572, and -174 were genotyped by amplifying the polymorphic region using polymerase chain reaction(PCR), restriction enzyme digestion and gel electrophoresis. RESULT: The genotype distributions for G/G, G/A and A/A genotypes of IL-6 -597 were 30.8%, 40.4%, and 28.8% in the GAP group and 53.3%, 40%, and 6.7% in the control group and were statistically different between 2 groups(p<0.05). Allele 2 frequency of IL-6 -597 were significantly higher in the GAP group than the control group(p<0.01). At the position of IL-6 -572, the distribution for C/C, C/G and G/G genotypes were 23.1%, 55.8% and 21.2% in the GAP group and 20%, 33.3%, and 46.7% in the control group. In female subjects, the genotype distribution were significantly different between 2 groups (p<0.01). In male subjects, allele 2 frequency of IL-6-572 was significantly lower in the GAP group than the control group(p<0.05). The genotype distribution of IL-6 -174 in the GAP group were 96.2%, 3.8% for G/G, G/C genotypes whereas only the G/G genotype was detected in the control group. CONCLUSION: In conclusion, significant associations were found in IL-6 gene promoter(-597, -572) polymorphisms and generalized aggressive periodontitis. Further cohort study will be necessary in larger population.

Autogenous transplantation of tooth with complete root formation / 대한치주과학회지

PURPOSE: Autogenous transplantation of teeth can be defined as transplantation of teeth from one site to another in the same individual, involving transfer of impacted or erupted teeth into extraction sites or surgically prepared sockets". Successful autogenous transplantation of teeth depends upon a complex variety of factors. Such factors include damage to the periodontal ligament of the donor tooth, residual bone height of the recipient site, extra-oral time of tooth during surgery. Schwartz and Andreasen previously reported that autogenous transplantation of teeth with incomplete root formation demonstrated higher success rate than that of teeth with complete root formation. Gault and Mejare yielded similar rate of successful autogenous transplantation both in teeth with complete root formation and in teeth with incomplete root formation when appropriate cases were selected. This case report was aimed at the clinical and radiographic view in autogenous transplantation of teeth with complete root formation. MATERIALS AND METHODS: Patients who presented to the department of periodontics, Chonnam National University Hospital underwent autogenous transplantation of teeth. One patient had vertical root fracture in a upper right second molar and upper left third molar was transplanted. And another patient who needed orthodontic treatment had residual root due to caries on upper right first premolar. Upper right premolar was extracted and lower right second premolar was transplanted. Six months later, orthodontic force was applied. RESULTS: 7 months or 11/2 year later, each patient had clinically shallow pocket depth and normal tooth mobility. Root resorption and bone loss were not observed in radiograph and function was maintained successfully. CONCLUSION: Autogenous transplantation is considered as a predictive procedure when it is performed for the appropriate indication and when maintenance is achieved through regular radiographic taking and follow-up.

Survival analysis of implants placed in the sinus floor elevated maxilla / 대한치주과학회지

OBJECTIVE: The sinus floor elevation procedures have been used to facilitate implant placement in the severely atrophic posterior maxilla. Many variables may have an influence on the outcomes of the sinus floor elevation in combination with implant treatment. The aim of this study was to analyze survival rate of implants placed in the edentulous maxillae of patients in whom sinus floor elevation was undertaken according to variables. MATERIALS AND METHODS: It consisted of 96 patients(50 male and 46 female), ranging in age from 31 to 70 years(mean 49 years), who underwent sinus floor elevation procedure(94 implants in left side and 106 implants in right side) from 2001 to 2002. A total of 200 implants were placed in the grafted sinus(73 implants in lateral approach and 127 implants in crestal approach). All implants were restored by fixed prosthesis. All patients were healthy. Follow-up periods for implants were between 48 to 60 months. RESULTS: The cumulative survival rate of implants was 91.5%. Gender, age and operation site did not have an influence on the survival rate. There was statistically significant differences for the implants which placed in less than 4 or 5 mm residual bone height, the survival rate was 60%, 81.4% respectively (p<0.05). There was no statistically significant difference of implants survival rate according to approach technique. The survival rate for 100% autogenous bone grafts was lower with respect to composite grafts containing autogenous bone and 100% substitutes. The survival rate for hydroxyapatite-coated implants was statistically significant lower than other textured group (p<0.05). CONCLUSION: Residual bone height, surface texture and graft materials have an influence on the survival rate. To use autogenous bone as a part of a composite bone replacement, implant texture which leads to more favorable implant-bone interface were necessary. To determine residual bone height for initial implant stability was important.

Clinical short-term effects of full-mouth disinfection / 대한치주과학회지

Full-mouth disinfection (Fdis) completes the entire scaling and root planing (SRP) in one stage within 24 hours for the prevention of microbial recolonization from untreated sites and ecological niches. The aim of this study is to compare the clinical short-term effects of modified Fdis with those of the conventional SRP in the therapy of moderate and severe chronic periodontitis. Modified Fdis group (5 patients) received the entire SRP within 24 hours using chlorhexidine solution (0.1%) and conventional SRP group (5 patients) received SRP per quadrant at one-week intervals. Clinical parameters were measured at baseline, one month and three months after both therapies. The results of this case report were as follows: 1. There were considerable decreases in sulcus bleeding index and plaque index one month after Fdis. 2. The mean probing depth of single-rooted teeth decreased more in Fdis group than conventional SRP group after therapy and, that of multi-rooted teeth decreased similarly in both groups. 3. The mean probing depth decreased 1.77mm in case of initial probing depth of 4-6mm and it decreased 4.13mm in case of initial probing depth of > or = 7mm three months after Fdis. 4. There were the smaller increases in gingival recession together with the larger gains in attachment in Fdis group than conventional SRP group after three months. Within the limitations of this study, one could conclude that Fdis has beneficial clinical effects in the treatment of moderate and severe chronic periodontitis and further research would be helpful including more subjects during a longer period to confirm the beneficial long-term effects of Fdis.

IL-10 gene promoter polymorphisms in Korean generalized aggressive periodontitis patients / 대한치주과학회지

Genetic polymorphisms associated with aggressive periodontitis have previously been reported. Interleukin-10 is an immunoregulatory cyto ine that plays a role in the patho genesis of periodontitis. Individual capacity for IL-10 production appears to be under genetic influence. The aim of present investigation was to explore possible genetic association of IL-10 gene promoter polymorphisms with generalized aggressive periodontitis. The study population consisted of 37 generalized aggressive periodontitis patients from the Department of Periodontology, Chonnam National University Hospital and 27 control subjects, all the subjects were non-smokers. Genomic DNA was obtained from buccal swab. The IL-10 promoter -597, -824, -1082 positions were genotyped by amplifying the polymorphic regions using polymerase chain reaction (PCR), followed by restriction enzyme digestion and gel electrophoresis. IL-10-597 C (allele 1) to A (allele 2) and IL-10-824 C (allele 1) to T (allele 2) and IL-10-1082 G (allele 1) to A (allele 2) polymorphisms were examined. The results were as follows. 1. In patients, the distribution of genotypes C/C, C/A and A/A at Il-10-597 was determined to be 13.5%, 37.8% and 48.7%, respectively and the distribution of genotypes at IL-10-824 was the same as that of IL-10-597. The distribution of genotypes G/G, G/A and A/A at IL-10-1082 was found to be 2.7%, 16.2% and 81.4%, respectively. No statistical difference in genotype distribution was found between the patient and control groups. 2. Allele 2 carriage rate at the three position of the IL-10 promoter region was higher in the control group than the patient group. 3. Allele 2 frequencies at IL-10-597 and -824 positions were higher in female group than male group and its difference was statistically significant(p<0.05). No significant difference in genotype distribution between the control and patient groups. Allele frequency between control and patient groups was not significantly different although allele 2 frequency at the three positions in the IL-10 promoter region appeared to be higher in control group. In conclusion, no clear association between IL-10 gene promoter polymorphisms and generalized aggressive periodontitis in Korean was observed.

Expression of Superoxide Dismutase Isoforms in Inflamed Gingiva / 대한치주과학회지

No abstract available.