An animal periodontitis model is essential for research on the pathogenesis and treatment of periodontal disease. In this study, we have introduced a lipopolysaccharide (LPS) of a periodontal pathogen to the alveolar bone defect of experimental animals and investigated its suitability as a periodontitis model.
Alveolar bone defects were made in both sides of the mandibular third premolar region of nine beagle dogs. Then, the animals were divided into the following groups: silk ligature tied on the cervical region of tooth group, Porphyromonas gingivalis LPS (P.g. LPS)-saturated collagen with silk ligature group, and no ligature or P.g. LPS application group as the control. The plaque index and gingival index were measured at 0 and 4 weeks postoperatively. The animals were then euthanized and prepared for histologic evaluation.
The silk ligature group and P.g. LPS with silk ligature group showed a significantly higher plaque index at 4 weeks compared to the control (P<0.05). No significant difference was found in the plaque index between the silk ligature group and P.g. LPS with silk ligature group. The P.g. LPS with silk ligature group showed a significantly higher gingival index compared to the silk ligature group or the control at 4 weeks (P<0.05). Histologic examination presented increased inflammatory cell infiltration in the gingival tissue and alveolar bone of the P.g. LPS with silk ligature group.
An additional P.g. LPS-saturated collagen with silk ligature ensured periodontal inflammation at 4 weeks. Therefore, P.g. LPS with silk ligature application to surgically created alveolar bone defects may be a candidate model for experimental periodontitis.
Animal models; Lipopolysaccharides; Periodontitis; Porphyromonas gingivalis
The level of the implant above the marginal bone and flap design have an effect on the bone resorption during the healing period. The aim of this study is to detect the relationship between the level of the implant at the implant placement and the bone level at the healing period in the mesial and distal side of implants placed with flapless (FL) and full-thickness flap (FT) methods.
Twenty-two nonsubmerged implants were placed with the FL and FT technique. Periapical radiographs were taken of the patient at implant placement, and at 6 and 12 weeks. By using computer software, bone level measurements were taken from the shoulder of the healing cap to the first bone implant contact in the mesial and distal side of the implant surface.
At 6 weeks, the correlation between the crestal bone level at the implant placement and crestal bone level of the FT mesially was significant (Pearson correlation coefficient=0.675, P<0.023). At 12 weeks, in the FT mesially, the correlation was nonsignificant (Spearman correlation coefficient=0.297, P<0.346). At 6 weeks in the FT distally, the correlation was nonsignificant (Pearson correlation coefficient=0.512, P<0.107). At 12 weeks in the FT distally, the correlation was significant (Spearman correlation coefficient=0.730, P<0.011). At 6 weeks in the FL mesially, the correlation was nonsignificant (Spearman correlation coefficient=0.083, P<0.809). At 12 weeks in the FL mesially, the correlation was nonsignificant (Spearman correlation coefficient=0.062, P<0.856). At 6 weeks in the FL distally, the correlation was nonsignificant (Spearman correlation coefficient=0.197, P<0.562). At 12 weeks in the FL distally, the correlation was significant (Pearson correlation coefficient=0.692, P<0.018).
A larger sample size is recommended to verify the conclusions in this preliminary study. The bone level during the healing period in the FT was more positively correlated with the implant level at implant placement than in the FL.
Bone resorption; Clinical trial; Dental implantation; Oral surgical procedures
This study examined the factors that can be associated with the appearance of the interproximal papilla.
One hundred and forty-seven healthy interproximal papillae between the maxillary central incisors were examined. For each subject, a digital photograph and periapical radiograph of the interdental embrasure were taken using a 1-mm grid metal piece. The following parameters were recorded: the amount of recession of the interproximal papilla, contact point-bone crest distance, contact point-cemento-enamel junction (CEJ) distance, CEJ-bone crest distance, inter-radicular distance, tooth shape, embrasure space size, interproximal contact area, gingival biotype, papilla height, and papilla tip form.
The amount of recession of the interproximal papilla was associated with the following: 1) increase in contact point-bone crest, contact point-CEJ, and CEJ-bone crest distance; 2) increase in the inter-radicular distance; 3) triangular tooth shape; 4) decrease in the interproximal contact area length; 5) increase in the embrasure space size; and 6) flat papilla tip form. On the other hand, the amount of gingival recession was not associated with the gingival biotype or papilla height. In the triangular tooth shape, the contact point-bone crest distance and inter-radicular distance were longer, the interproximal contact area length was shorter, and the embrasure space size was larger. The papilla tip form became flatter with increasing inter-radicular distance and CEJ-bone crest distance.
The relative position of the interproximal papilla in healthy subjects was associated with the multiple factors and each factor was related to the others. A triangular tooth shape carries a higher risk of recession of the interproximal papilla because the proximal contact point is positioned more incisally and the bone crest is positioned more apically. This results in an increase in recession of the interproximal papilla and flat papilla tip form.
Gingiva; Gingival recession
The purpose of the current study was to examine the effect of dexamethasone (Dex) at various concentrations on the apoptosis and mineralization of human periodontal ligament (hPDL) cells.
hPDL cells were obtained from the mid-third of premolars extracted for orthodontic reasons, and a primary culture of hPDL cells was prepared using an explant technique. Groups of cells were divided according to the concentration of Dex (0, 1, 10, 100, and 1,000 nM). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed for evaluation of cellular viability, and alkaline phosphatase activity was examined for osteogenic differentiation of hPDL cells. Alizarin Red S staining was performed for observation of mineralization, and real-time polymerase chain reaction was performed for the evaluation of related genes.
Increasing the Dex concentration was found to reduce cellular viability, with an increase in alkaline phosphatase activity and mineralization. Within the range of Dex concentrations tested in this study, 100 nM of Dex was found to promote the most vigorous differentiation and mineralization of hPDL cells. Dex-induced osteogenic differentiation and mineralization was accompanied by an increase in the level of osteogenic and apoptosis-related genes and a reduction in the level of antiapoptotic genes. The decrease in hPDL cellular viability by glucocorticoid may be explained in part by the increased prevalence of cell apoptosis, as demonstrated by BAX expression and decreased expression of the antiapoptotic gene, Bcl-2.
An increase in hPDL cell differentiation rather than cellular viability at an early stage is likely to be a key factor in glucocorticoid induced mineralization. In addition, apoptosis might play an important role in Dex-induced tissue regeneration; however, further study is needed for investigation of the precise mechanism.
Apoptosis; Cell differentiation; Cell survival; Dexamethasone; Periodontal ligament
Diabetes and periodontal disease are two common diseases with high prevalence rates. Recent evidence has shown a bidirectional relationship between diabetes and periodontitis. The aim of this study was to investigate the effects of nonsurgical periodontal therapy on glycemic control in type 2 diabetes mellitus patients.
Sixty subjects aged 35-45 years with blood sugar controlled by oral hypoglycaemic agents were randomly divided equally among 3 groups: group A (scaling, mouthwash, and brushing), group B (mouthwash and brushing), and group C (brushing only). Glycated haemoglobin (HbA1c), fasting blood sugar (FBS), probing pocket depth (PPD), gingival index (GI), plaque index (PI), and the relevant drug history were recorded at baseline and after 3 months of intervention. Comparison of the mean difference among the variables was performed by parametric and nonparametric tests, which were further evaluated using multiple regression analysis.
The mean differences between the PPD, FBS, HbA1c, GI, and PI in groups A and B were found to be statistically significant (P<0.001). Multiple regression analysis in group A showed that out of all the independent variables, GI and frequency of drug administration independently (b=0.3761 and b=0.598) showed a significantly greater impact on HbA1c (R2=0.832, P<0.05).
Nonsurgical periodontal therapy can effectively decrease HbA1c levels in type 2 diabetes mellitus patients on medication.
Glycosylated hemoglobin A; Periodontal debridement; Type II diabetes mellitus
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.
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.
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.
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.
Chronic periodontitis; Disease progression; Geriatrics; Microbiology; Real-time polymerase chain reaction; Saliva
Nitric oxide (NO) is a short-lived bioactive molecule that is known to play an important role in the pathogenesis of periodontal disease. In the current study, we investigated the effect of the flavonoid quercetin on the production of NO in murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen related to inflammatory periodontal disease, and tried to elucidate the underlying mechanisms of action.
LPS was isolated from P. intermedia ATCC 25611 cells by the standard hot phenol-water method. The concentration of NO in cell culture supernatants was determined by measuring the accumulation of nitrite. Inducible NO synthase (iNOS) and heme oxygenase-1 (HO-1) protein expression, phosphorylation of c-Jun N-terminal kinase (JNK) and p38, inhibitory κB (IκB)-α degradation, and signal transducer and activator of transcription 1 (STAT1) phosphorylation were analyzed via immunoblotting.
Quercetin significantly attenuated iNOS-derived NO production in RAW246.7 cells activated by P. intermedia LPS. In addition, quercetin induced HO-1 protein expression in cells activated with P. intermedia LPS. Tin protoporphyrin IX (SnPP), a competitive inhibitor of HO-1, abolished the inhibitory effect of quercetin on LPS-induced NO production. Quercetin did not affect the phosphorylation of JNK and p38 induced by P. intermedia LPS. The degradation of IκB-α induced by P. intermedia LPS was inhibited when the cells were treated with quercetin. Quercetin also inhibited LPS-induced STAT1 signaling.
Quercetin significantly inhibits iNOS-derived NO production in murine macrophages activated by P. intermedia LPS via anti-inflammatory HO-1 induction and inhibition of the nuclear factor-κB and STAT1 signaling pathways. Our study suggests that quercetin may contribute to the modulation of host-destructive responses mediated by NO and appears to have potential as a novel therapeutic agent for treating inflammatory periodontal disease.
Lipopolysaccharides; Nitric oxide; Periodontal diseases; Prevotella intermedia; Quercetin
The aim of this study was to evaluate the surface properties and biological response of an anodized titanium surface by cell proliferation and alkaline phosphatase activity analysis.
Commercial pure titanium (Ti) disks were prepared. The samples were divided into an untreated machined Ti group and anodized Ti group. The anodization of cp-Ti was formed using a constant voltage of 270 V for 60 seconds. The surface properties were evaluated using scanning electron microscopy, X-ray photoelectron spectroscopy, and an image analyzing microscope. The surface roughness was evaluated by atomic force microscopy and a profilometer. The contact angle and surface energy were analyzed. Cell adhesion, cell proliferation, and alkaline phosphatase activity were evaluated using mouse MC3T3-E1 cells.
The anodized Ti group had a more porous and thicker layer on its surface. The surface roughness of the two groups measured by the profilometer showed no significant difference (P>0.001). The anodized Ti dioxide (TiO2) surface exhibited better corrosion resistance and showed a significantly lower contact angle than the machined Ti surface (P>0.001). Although there was no significant difference in the cell viability between the two groups (P>0.001), the anodized TiO2 surface showed significantly enhanced alkaline phosphatase activity (P<0.001).
These results suggest that the surface modification of Ti by anodic oxidation improved the osteogenic response of the osteoblast cells.
Cell proliferation; Dental implants; Titanium; Titanium oxide
Periodontitis is a common oral disease that is characterized by infection and inflammation of the tooth supporting tissues. While its incidence is highly associated with outgrowth of the pathogenic microbiome, some patients show signs of predisposition and quickly fall into recurrence after treatment. Recent research using genetic associations of candidates as well as genome-wide analysis highlights that variations in genes related to the inflammatory response are associated with an increased risk of periodontitis. Intriguingly, some of the genes are regulated by epigenetic modifications, supposedly established and reprogrammed in response to environmental stimuli. In addition, the treatment with epigenetic drugs improves treatment of periodontitis in a mouse model. In this review, we highlight some of the recent progress identifying genetic factors associated with periodontitis and point to promising approaches in epigenetic research that may contribute to the understanding of molecular mechanisms involving different responses in individuals and the early detection of predispositions that may guide in future oral treatment and disease prevention.
DNA methylation; Epigenetics; Genetic variation; Histone code; Inflammation; Periodontitis
The present study has two aims; firstly, it attempts to verify the presence of oxidative stress by estimating the reactive oxygen species (ROS) levels in periodontal pockets ≥5 mm as compared to controls. The second aim is to evaluate the effect of lycopene as a locally delivered antioxidant gel on periodontal health and on the gingival crevicular fluid (GCF) levels of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative injury.
Thirty-one subjects participated in this study. In the pretreatment phase, the ROS levels in pockets ≥5 mm were measured by flow cytometry. Three sites in each subject were randomly assigned into each of the following experimental groups: sham group, only scaling and root planing (SRP) was done; placebo group, local delivery of placebo gel after SRP; and lycopene group, local delivery of lycopene gel after SRP. Clinical parameters included recording site-specific measures of GCF 8-OHdG, plaque, gingivitis, probing depth, and clinical attachment level.
The gel, when delivered to the sites with oxidative stress, was effective in increasing clinical attachment and in reducing gingival inflammation, probing depth, and 8-OHdG levels as compared to the placebo and sham sites.
From this trial conducted over a period of 6 months, it was found that locally delivered lycopene seems to be effective in reducing the measures of oxidative stress and periodontal disease.
Antioxidants; Oxidative stress; Periodontitis
The purpose of this study was to evaluate the tensile strength of surgical synthetic absorbable sutures over a period of 14 days under simulated oral conditions.
Three suture materials (polyglycolic acid [PGA], polyglactin [PG] 910, and poly (glycolide-co-є-caprolactone) [PGC]) were used in 4-0 and 5-0 gauges. 210 suture samples (35 of each material and gauge) were used. All of the samples were tested preimmersion and 1 hour and 1, 3, 7, 10, and 14 days postimmersion. The tensile strength of each suture material and gauge was assessed. The point of breakage and the resorption pattern of the sutures were also assessed.
During the first 24 hours of immersion, all 4-0 and 5-0 samples of PGA, PG 910, and PGC maintained their initial tensile strength. At baseline (preimmersion), there was a statistically significant (P<0.001) difference in the tensile strengths between the 4-0 and 5-0 gauge of PGA, PG 910, and PGC. PGA 4-0 showed the highest tensile strength until day 10. At 7 days, all the 4-0 sutures of the three materials had maintained their tensile strength with PGA 4-0 having significantly greater (P=0.003) tensile strength compared to PG.
4-0 sutures are stronger and have greater tensile strength than 5-0 sutures. The PGA 4-0 suture showed the highest tensile strength at the end of day 10.
Polyglactin 910; Polyglycolic acid; Sutures; Tensile strength
The aim of this study was to identify a role for endodontic intervention in enhancing the regenerative potential of the periodontal ligament when combined with periodontal treatment in seriously involved teeth with a secondary endodontic component.
Patients who exhibited radiolucency extending to the periapical region, abnormal electric pulp testing values, and deep probing depth derived from primary periodontal disease with secondary endodontic involvement were included. Intentional root canal treatment was applied to those teeth in which the apical lesions were presumed to communicate with those of the periodontal lesion of the teeth that remained vital. In all three selected cases, regenerative periodontal therapy incorporating either bone graft or guided tissue regeneration was instituted 3 months after the endodontic intervention.
Remarkable enhancement in radiographic density was noticeable around the affected teeth as evidenced by changes in radiopacity. There was a significant reduction in the probing pocket depth and gain in the clinical attachment level. Chewing discomfort gradually disappeared from the commencement of the combined treatment.
An intentional endodontic intervention may be a worthwhile approach for the sophisticated management of teeth suffering from serious attachment loss and alveolar bone destruction with concomitant secondary endodontic involvement.
Periodontal attachment loss; Periodontal disease; Root canal therapy
The present study aimed to measure root surface roughness in teeth with periodontitis by a profilometer following root planning with ultrasonic and hand instruments with and without erbium-doped yttrium aluminium garnet (Er:YAG) laser irradiation.
Sixty single-rooted maxillary and mandibular teeth, extracted because of periodontal disease, were collected. The crowns and apices of the roots were cut off using a diamond bur and water coolant. The specimens were mounted in an acrylic resin block such that a plain root surface was accessible. After primary evaluation and setting a baseline, the samples were divided into 4 groups. In group 1, the samples were root planned using a manual curette. The group 2 samples were prepared with an ultrasonic scaler. In group 3, after scaling with hand instrumentation, the roots were treated with a Smart 1240D plus Er:YAG laser and in group 4, the roots were prepared with ultrasonic scaler and subsequently treated with an Er:YAG laser. Root surface roughness was then measured by a profilometer (MahrSurf M300+RD18C system) under controlled laboratory conditions at a temperature of 25℃ and 41% humidity. The data were analyzed statistically using analysis of variance and a t-test (P<0.05).
Significant differences were detected in terms of surface roughness and surface distortion before and after treatment. The average reduction of the surface roughness after treatment in groups 1, 2, 3, and 4 was 1.89, 1.88, 1.40, and 1.52, respectively. These findings revealed no significant differences among the four groups.
An Er:YAG laser as an adjunct to traditional scaling and root planning reduces root surface roughness. However, the surface ultrastructure is more irregular than when using conventional methods.
Laser therapy; Periodontitis; Tooth; Ultrasonics
Implant treatment has become the treatment of choice to replace missing teeth in partially edentulous areas. Dental implants present different biological and biomechanical characteristics than natural teeth. Occlusion is considered to be one of the most important factors contributing to implant success. Most literature on implant occlusal concepts is based on expert opinion, anecdotal experiences, in vitro and animal studies, and only limited clinical research. Furthermore, scientific literature regarding implant occlusion, particularly in implant-supported fixed dental prostheses remains controversial. In this study, the current status of implant occlusion was reviewed and discussed. Further randomized clinical research to investigate the correlation between implant occlusion, the implant success rate, and its risk factors is warranted to determine best clinical practices.
Dental implants; Dental occlusion; Fixed partial denture; Implant-supported dental prosthesis; Review
The aim of this study was to measure the peri-implant bone length surrounding implants that penetrate the sinus membrane at the posterior maxilla and to evaluate the survival rate of these implants.
Treatment records and orthopantomographs of 39 patients were reviewed and analyzed. The patients had partial edentulism at the posterior maxilla and limited vertical bone height below the maxillary sinus. Implants were inserted into the posterior maxilla, penetrating the sinus membrane. Four months after implant insertion, provisional resin restorations were temporarily cemented to the abutments and used for one month. Then, a final impression was taken at the abutment level, and final cement-retained restorations were delivered with mutually protected occlusion. The complications from the implant surgery were examined, the number of failed implants was counted, and the survival rate was calculated. The peri-implant bone lengths were measured using radiographs. The changes in initial and final peri-implant bone lengths were statistically analyzed.
Nasal bleeding occurred after implant surgery in three patients. No other complications were found. There were no failures of the investigated implants, resulting in a survival rate of 100%. Significantly more bone gain around the implants (estimated difference=-0.6 mm, P=0.025) occurred when the initial residual bone height was less than 5 mm compared to the >5 mm groups. No significant change in peri-implant bone length was detected when the initial residual bone height was 5 mm or larger.
This study suggests that implants penetrating the sinus membrane at the posterior maxilla in patients with limited vertical bone height may be safe and functional.
Biomechanics; Biostatistics; Maxilla; Maxillary sinus; Sinus floor augmentation
The objective of this study was to elucidate the role of collagen membranes (CMs) when used in conjunction with bovine hydroxyapatite particles incorporated with collagen matrix (BHC) for lateral onlay grafts in dogs.
The first, second, and third premolars in the right maxilla of mongrel dogs (n=5) were extracted. After 2 months of healing, two BHC blocks (4 mm×4 mm×5 mm) were placed on the buccal ridge, one with and one without the coverage by a CM. The animals were sacrificed after 8 weeks for histometric analysis.
The collagen network of the membranes remained and served as a barrier. The quantity and quality of bone regeneration were all significantly greater in the membrane group than in the no-membrane group (P<0.05).
The use of barrier membranes in lateral onlay grafts leads to superior new bone formation and bone quality compared with bone graft alone.
Alveolar ridge augmentation; Bone substitutes; Collagen; Guided tissue regeneration; Membranes
The purpose of this study was to compare the phototoxic effects of blue light exposure on periodontal pathogens in both planktonic and biofilm cultures.
Strains of Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis, in planktonic or biofilm states, were exposed to visible light at wavelengths of 400.520 nm. A quartz-tungsten-halogen lamp at a power density of 500 mW/cm2 was used for the light source. Each sample was exposed to 15, 30, 60, 90, or 120 seconds of each bacterial strain in the planktonic or biofilm state. Confocal scanning laser microscopy (CSLM) was used to observe the distribution of live/dead bacterial cells in biofilms. After light exposure, the bacterial killing rates were calculated from colony forming unit (CFU) counts.
CLSM images that were obtained from biofilms showed a mixture of dead and live bacterial cells extending to a depth of 30-45 µm. Obvious differences in the live-to-dead bacterial cell ratio were found in P. gingivalis biofilm according to light exposure time. In the planktonic state, almost all bacteria were killed with 60 seconds of light exposure to F. nucleatum (99.1%) and with 15 seconds to P. gingivalis (100%). In the biofilm state, however, only the CFU of P. gingivalis demonstrated a decreasing tendency with increasing light exposure time, and there was a lower efficacy of phototoxicity to P. gingivalis as biofilm than in the planktonic state.
Blue light exposure using a dental halogen curing unit is effective in reducing periodontal pathogens in the planktonic state. It is recommended that an adjunctive exogenous photosensitizer be used and that pathogens be exposed to visible light for clinical antimicrobial periodontal therapy.
Biofilms; Dental curing lights
The purpose of study was to compare glycemic control using glycated hemoglobin levels (HbA1c) in diabetic patients with chronic generalized periodontitis (CGP) undergoing scaling and root planing (SRP) with and without systemic doxycycline.
Fifty subjects with type 2 diabetes mellitus (T2DM) and CGP receiving antidiabetic therapy were selected for study. The selected subjects were randomly assigned to two groups (test group [TG] and control group [CG]) comprising 25 patients each. The TG received SRP followed by systemic doxycycline. The CG received treatment with SRP only. The periodontal parameters were recorded at baseline (day zero), and every 1 month for 4 months and included probing depth, clinical attachment level, plaque index, gingival index, and HbA1c level were recorded at baseline (day zero) and at the end of 4 months.
A statistically significant effect was demonstrated for the periodontal parameters for both the TG and CG. HbA1c values did not show a statistically significant difference in the treatment group as compared to the CG.
The authors concluded that nonsurgical periodontal therapy improved glycemic control in patients with T2DM in both groups, but no statistical difference was observed with adjunctive systemic doxycycline therapy. A further study with a larger sample size is required.
Chronic periodontitis; Diabetes mellitus; Glycosylated hemoglobin A; Periodontal debridement
The purpose of this study was to analyze the expression of inducible nitric oxide synthases (iNOS), tissue inhibitors of metalloproteinase (TIMP)-3, and TIMP-4 in the gingival tissues of periodontal patients with or without type 2 diabetes mellitus (DM).
Depending on the patient's systemic condition and clinical criteria of the gingiva, each gingival sample was classified into one of three groups. Sixteen clinically, systemically healthy patients (group 1), 16 periodontal patients (group 2), and 16 periodontal patients with DM (group 3) were included. Tissue samples in each group were collected, prepared, and analyzed by western blotting. Quantification of the relative amount of TIMP-3, TIMP-4, and iNOS was performed.
The expression levels of iNOS and TIMP-3 both increased in group 1, group 2, and group 3 in increasing order, and were significantly higher in both group 2 and group 3 as compared to group 1 (P<0.05). The expression levels of TIMP-4 increased in the same order, but significantly increased in group 2 as compared to group 1, in group 3 as compared to group 1, and group 3 as compared to group 2 (P<0.05).
This study demonstrated that iNOS, TIMP-3, and TIMP-4 might be involved in the progression of periodontal inflammation associated with type 2 DM. It is thought that further study of these factors can be applied practically for the diagnosis and control of periodontitis in diabetics.
Chronic periodontitis; Diabetes mellitus; Nitric oxide synthase; Tissue inhibitor of metalloproteinases
Chronic periodontitis (CP) seems to be associated with stress and depression, but little information on this possible association is available in the literature. Thus, the objective of this study was to evaluate the association among stress, the salivary cortisol level (SCL), and CP.
Seventy systemically healthy subjects were included in the study from January to September 2011. Full medical and dental histories were obtained, and the following measurements were recorded: 1) probing depth; 2) clinical attachment level; 3) bleeding on probing; and 4) tooth mobility. Saliva samples were collected for the evaluation of SCL (via a highly sensitive electrochemiluminescence immunoassay), and all subjects also answered a questionnaire (i.e., the Zung Self-rating Depression Scale). The odds ratio (OR) with a 95% confidence interval (CI) was calculated, and one way analysis of variance and the Tukey-Kramer method were performed.
A total of 36 subjects with CP (51.4%) and 34 without CP were evaluated. Of them, all of the subjects with CP and one periodontally healthy subject were diagnosed with depression. Subjects with moderate CP had statistically significantly higher levels of SCL than subjects with a diagnosis of slight CP (P=0.006). Also, subjects with severe CP showed the same outcome when compared to those with slight CP (P=0.012). In addition, 46 subjects presented high SCL whereas 24 had a normal level. CP was found to be correlated with the SCL, with an OR of 4.14 (95% CI, 1.43 to 12.01).
Subjects with a high SCL and depression may show an increased risk for CP.
Chronic periodontitis; Depressive disorder; Physiological stress; Saliva