Physical and mechanical changes on titanium base of three different types of hybrid abutment after cyclic loading.

PURPOSE: This study investigated the physical and mechanical changes in the titanium base of three different hybrid abutment materials after cyclic loading by estimating the post-load reverse torque value (RTV), compressive side fulcrum wear pattern of titanium base, and surface roughness. MATERIALS AND METHODS: A total of 24 dental implants were divided into three groups (n = 8 each): Group Z, LD, and P used zirconia, lithium disilicate, and polyetheretherketone, respectively, for hybrid abutment fabrication. RTV was evaluated after cyclic loading with 50 N for 1.2 × 106 chewing cycles. The compressive sides of the titanium bases were analyzed using a scanning electron microscope, and the roughness of the affected areas was measured using an optical profilometer after loading. Datasets were analyzed using Kruskal-Wallis test followed by Mann-Whitney tests with the Bonferroni correction (α = .05). RESULTS: Twenty-three samples passed the test; one LD sample fractured after 770,474 cycles. Post-load RTV varied significantly depending on the hybrid-abutment material (P = .020). Group P had a significantly higher median of post-load RTVs than group Z (16.5 and 14.3 Ncm, respectively). Groups LD and P showed minor signs of wear, and group Z showed a more pronounced wear pattern. While evaluating compressive side affected area roughness of titanium bases, lower medians were shown in group LD (Ra 0.16 and Rq 0.22 µm) and group P (Ra 0.16 and Rq 0.23 µm) than in group Z (Ra 0.26 and Rq 0.34 µm); significant differences were found only among the unaffected surface and group Z. CONCLUSION: The hybrid abutment material influences the post-load RTV. Group Z had a more pronounced wear pattern on the compressive side of titanium base; however, the surface roughness was not statistically different among the hybrid-abutment groups.

A comparative biomechanical study of original and compatible titanium bases: evaluation of screw loosening and 3D-crown displacement following cyclic loading analysis.

PURPOSE: This study evaluated screw loosening and 3D crown displacement after cyclic loading of implant-supported incisor crowns cemented with original titanium bases or with three compatible, nonoriginal components. MATERIALS AND METHODS: A total of 32 dental implants were divided into four groups (n = 8 each): Group 1 used original titanium bases, while Groups 2-4 used compatible components. The reverse torque value (RTV) was evaluated prior to and after cyclic loading (1,200,000 cycles). Samples (prior to and after cyclic loading) were scanned with a microcomputed tomography (micro-CT). Preload and postload files were superimposed by 3D inspection software, and 3D crown displacement analysis was performed using root-mean-square (RMS) values. All datasets were analyzed using one-way ANOVA and Tukey's post hoc analysis. RESULTS: Significant variations were observed in the postload RTV, depending on the titanium base brand (P < .001). The mean postload RTVs were significantly higher in Groups 1 and 2 than in the other study groups. While evaluating 3D crown displacement, the lowest mean RMS value was shown in the original Group 1, with the highest RMS value occurring in Group 4. CONCLUSION: Within the limitations of this in vitro study and under the implemented conditions, it was concluded that the manufacturer brand of the titanium base significantly influenced screw loosening following the fatigue test and influenced 3D crown displacement after cyclic loading.

Expression of Interleukin-17, Tumor Necrosis Factor-Alpha, and Matrix Metalloproteinase-8 in Patients with Chronic Peri-Implant Mucositis.

BACKGROUND The present study aimed to evaluate whether non-surgical treatment interferes with clinical parameters and local patterns of osteo-immunoinflammatory mediators (IL-17 and TNF-alpha) and matrix metalloproteinase-8 (MMP-8) that are found in peri-implant crevicular fluid (PICF) and biofilms during the progression of peri-implant mucositis. MATERIAL AND METHODS We selected 30 patients with peri-implant caused mucositis before (MP) and after treatment (TP) and 30 healthy people (HP) for the analysis of IL-17, TNF-alpha cytokine, and MMP-8 production in PICF and for analysis of colonization dynamics of periodontopathogenic bacteria in supra- and subgingival plaque samples. The levels of IL-17 and MMP-8 concentrations in samples were assayed by enzymatic immunosorbent assay (ELISA) and TNF-alpha levels were determined by enzyme amplified sensitivity immunoassay (EASIA) method in PICF. The micro-IDent test was used to detect 11 species of periodontopathogenic bacteria in subgingival biofilm. RESULTS We found significantly (P<0.001) higher levels of IL-17, TNF-alpha, and MMP-8 in the PICF of the MP and TP groups in comparison to the HP group. A significant association was found in MP associated with Parvimonas micra, as TNF-alpha in PICF was significantly higher (P=0.034) than in patients without Parvimonas micra. TNF-alpha levels in the samples of PICF showed a moderate correlation with clinical parameters, including plaque index (PI) (P=0.007) and MMP-8 levels (P=0.001), in the MP group. CONCLUSIONS Assessment of levels of inflammatory cytokines in PICF can aid in the identification of peri-implant mucositis, which can assist in early diagnosis, prevention, and treatment.

Interleukin-10 and Interleukin-1ß Cytokines Expression in Leukocytes of Patients with Chronic Peri-Mucositis.

BACKGROUND The purpose of the present research is to analyze the effect of polyphenols and flavonoids substrat (PFS) from plants Calendula officinalis, Salvia fruticosa, Achillea millefolium, and propolis as immunomodulatory in the production of interleukin (IL)-1ß and IL-10 in peripheral blood leukocytes medium (PBLM) in patients who were diagnosed with mucositis of peri-implant tissue compared to patients with healthy implant tissue. It was hypothesized that IL-1ß and IL-10 contribute to the inflammation processes noticed in the diseases of peri-implant tissues. MATERIAL AND METHODS Sixty non-smoking patients were included in this study: patients with healthy implants (HP group) and patients with peri-implant mucositis (MP group). Peri-mucositis was diagnosed by radiologic and clinical examination. The PBLM from MP were treated with PFS at various concentrations. The levels of IL-10 and IL-1ß excreted by the PBLM stimulated and unstimulated with viable Porphyromonas gingivalis test-tube were committed by the enzyme amplified immunoassay sensitivity method. RESULTS Unstimulated and stimulated PBLM and treatment with 5.0 mg/mL or 10.0 mg/mL of PFS in the MP group produced significantly higher levels IL-10 (P<0.001) that analogous mediums of the HP group. The levels of IL-1ß decreased more considerably in the stimulated PBLM of the MP group than in those of HP group (P<0.001) after the treatment with PFS at only 10.0 mg/mL concentration. CONCLUSIONS Theses results suggest that the solution of PFS might offer a new potential for the development of a new therapeutic path to prevent and treat peri-implant mucositis.

The prevalence of facial and dentolabial parameters among students of the Faculty of Dentistry of Lithuanian University of Health Sciences.

OBJECTIVE: Nowadays esthetic checklist is an indispensable assistance for the dental clinics. Processing the information recorded on it and integrating the esthetic evaluation with biologic and functional parameters will really allow dentist to formulate a correct diagnosis and to choose most suitable treatment plan for the patient. The aim of this study was to evaluate the prevalence of facial and dentolabial parameters among students of the Faculty of Dentistry of Lithuanian University of Health Sciences and to identify relationship of all facial and dentolabial parameters results. MATERIAL AND METHODS: The study is carried out at the Department of Dental and Maxillofacial Orthopedics of Lithuanian University of Health Sciences. The facial and dentolabial parameters of students are examined by visual examination using medical gloves and rulers. Participants were sitting on a chair at a distance of 150 cm in front of the researchers. RESULTS: The thick type of lips was the most popular for normal profile face, of thin lips - concave, of medium lips type - convex. The most popular of profile face types were normal and convex. The most popular tooth exposure among all smile line types was less than half teeth. Type when more than half of teeth was diagnosed in the most of high "Gummy smile". CONCLUSIONS: Was found relationship between: the profile of face and type of lips; the tooth exposure at rest and type of smile line; the commisural line vs horizon and interpupillary line vs horizon; the facial midline and occlusal plane vs commisural line/horizon; the type of smile line and type of lips; the labial corridor and 10 teeth number of smile width type.

Host responses to Candida albicans. A review.

Candida albicans is the most prevalent human fungal pathogen, that is component of the commensal microbial flora of the mouth. Under certain conditions, C. albicans can cause severe diseases, septicaemia, and death. The mass of infections made by this pathogen are connected with biofilm growth. This survey highlights the pathogenicity mechanisms of C. albicans and how this may lead to the induction of a protective immune response. The survey is based on the most recent and important literature available from the Medline database.

Peripheral Blood Leukocytes Interleukin-1 Beta (IL-1ß) Cytokine Hyper-Reactivity in Chronic Periodontitis.

BACKGROUND Levels of pro-inflammatory cytokine (IL-1ß) released by peripheral blood leukocyte medium (PBLM), isolated from chronic periodontitis patients (P) before therapy and matched to controls, were determined in the presence or absence of non-opsonized Escherichia coli and Staphylococcus aureus. MATERIAL AND METHODS In this investigation, 26 patients with untreated, severe, generalized, chronic periodontitis and 26 healthy subjects (H) were enrolled. Periodontal status was assessed by measuring bleeding on probing (BOP), clinical attachment loss (CAL), probing pocket depth (PPD), and Ramfjord index (PDI). The levels of IL-1ß (µg/ml) were assayed by a standard Immunoenzymetric Assay Diasource IL-1ß ELISA kit in PBLM. RESULTS Our study showed that the values of IL-1ß levels in PBLM of the P group (stimulated with non-opsonized E. coli and S. aureus) were significantly higher than in the analogous medium of H group subjects (P<0.001). All correlations between the cytokine levels of IL-1ß in the samples of PBLM (stimulated with non-opsonized E. coli and S. aureus) and clinical parameters such as BOP, PPD, CAL, and PDI were significantly higher in the group of patients with periodontitis. CONCLUSIONS Levels of IL-1ß secreted by leukocytes may help measure severe, generalized, chronic periodontitis, and can be predictive of future detrimental clinical sequelae associated with chronic periodontitis.

Relationship of clinical and microbiological variables in patients with type 1 diabetes mellitus and periodontitis.

BACKGROUND: The aim of the study was to analyze how metabolic control of type 1 diabetes is related to clinical and microbiological periodontal parameters. MATERIAL AND METHODS: The study involved 56 subjects aged from 19 to 50 years divided into 2 groups: healthy subjects (the H group), and diabetic (type 1 diabetes) patients with chronic untreated generalized periodontitis (the DM group). The glycosylated hemoglobin value (HbA1c) was determined using the UniCel DxC 800 SYNCHRON System (Beckman Coulter, USA), and the concentration in blood was measured by the turbidimetric immunoinhibition method. A molecular genetic assay (Micro-IDent plus, Germany) was used to detect periodontopathogenic bacteria in plaque samples. Periodontitis was confirmed by clinical and radiological examination. RESULTS: Fusobacterium nucleatum, Capnocytophaga species, and Eikenella corrodens were the most frequently found bacteria in dental plaque samples (77.8%, 66.7%, and 33.4%, respectively), whereas Aggregatibacter actinomycetemcomitans was identified 40.7% less frequently in the DM group than in the H group. The strongest relationship was observed between the presence of 2 periodontal pathogens - F. nucleatum and Capnocytophaga spp. - and poorer metabolic control in type 1 diabetes patients (HbA1c) and all clinical parameters of periodontal pathology. CONCLUSIONS: Periodontal disease was more evident in type 1 diabetic patients, and the prevalence of periodontitis was greatly increased in subjects with poorer metabolic control.

Viability changes: microbiological analysis of dental casts.

BACKGROUND: This study evaluated the survival of the most prevalent oral bacteria and fungi (Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans) in dental casts, and compared changes in the amounts of these microorganisms at different time intervals to determine how long dental casts may pose threat to the health of dental personnel and patients. MATERIAL AND METHODS: When manufacturing the casts, regular water was replaced with sterile distilled water, where suspensions of the studied bacteria or the fungus at certain concentrations were prepared. When the dental casts were fully set (solidified), plaster shavings were examined immediately after the contact of the studied microorganism with the plaster, as well as after 1, 2, 24, 48, 72, 96, and 120 hours. Following that, we measured how the amount of the studied bacteria and fungi in 1 gram of the plaster changed within the studied period of time. RESULTS: Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05). Staphylococcus aureus remained viable in plaster for up to 4 days, and the number of these bacteria dropped after 1 day (p<0.05). Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05). Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05). CONCLUSIONS: The microorganisms did not multiply in the gypsum casts and their number significantly dropped instead of increasing.

Effect of (1→3),(1→6)-ß-glucan on in vitro production of cytokines by leukocytes of patients with periodontitis.

BACKGROUND. The aim of the study was to investigate the effect of (1→3), (1→6)-ß-glucan on the production of interleukin 10 (IL-10) and tumor necrosis factor α (TNF-α) in vitro by peripheral blood leukocytes of patients with periodontitis. MATERIAL AND METHODS. In total, 20 patients suffering from untreated severe chronic generalized periodontitis were enrolled in this study. Periodontitis was confirmed by clinical and radiologic examination. Besides, 20 periodontally healthy patients served as a control group. Peripheral venous blood was sampled from the patients, and isolated leukocytes were treated with (1→3),(1→6)-ß-glucan from yeast at different concentrations. The levels of IL-10 and TNF-α secreted by the leukocytes unstimulated and stimulated with unopsonized E. coli in vitro were determined by the enzyme amplified sensitivity immunoassay method. RESULTS. Our data showed that (1→3),(1→6)-ß-glucan induced a significant decrease (P<0.05) in the TNF-α level and a significant increase (P<0.001) in the IL-10 level in the media of unstimulated and stimulated leukocytes of the patients with periodontitis in comparison with those of the healthy subjects. CONCLUSIONS. The present in vitro study showed that (1→3),(1→6)-ß-glucan modulated the response of leukocytes of the patients with periodontitis differently in comparison with those of the healthy subjects. It increased the release of IL-10, which is protective of the tooth-supporting tissues in patients with periodontal disease, but decreased the release of TNF-α, which is mainly responsible for the destruction of the tooth-supporting tissues during periodontal disease.

Activity of neutrophil ß-glucuronidase in diabetic and nondiabetic patients with chronic generalized periodontitis and healthy subjects.

OBJECTIVE. The aim of the study was to establish the dynamics of ß-glucuronidase activity in subjects suffering from type 1 diabetes and chronic untreated generalized periodontitis, subjects suffering from chronic untreated generalized periodontitis only, and control subjects not suffering from generic diseases with healthy periodontal tissue. MATERIAL AND METHODS. The study involved 165 19-50-year-old subjects who were divided into three groups: healthy subjects (n=55), subjects with chronic untreated generalized periodontitis (n=55), and subjects with type 1 diabetes and chronic untreated generalized periodontitis (n=55). Neutrophilic leukocytes of peripheral venous blood were exposed to bacterial stimuli: opsonized zymosan, nonopsonized Staphylococcus aureus, and prodigiosan. The activity of ß-glucuronidase was determined by the spectrofluorimetry method. RESULTS. The diagnostic value of changes in ß-glucuronidase activity of neutrophilic leukocytes markedly increased in all study groups after stimulation of neutrophilic leukocytes by opsonized zymosan, nonopsonized Staphylococcus aureus, and prodigiosan as compared to control media not exposed to any stimulus (P<0.001). The strongest relationship (canonical correlation coefficient eta, 0.993) between the intensity of periodontal pathology markers and the activity of ß-glucuronidase of neutrophilic leukocytes in incubated media in patients with type 1 diabetes mellitus and periodontitis was found under the effect of nonopsonized Staphylococcus aureus. CONCLUSIONS. If periodontal impairment is severe, diabetes mellitus possibly causes a faster destruction of the periodontal tissue and presents a higher risk of periodontitis for patients with diabetes.

Dental caries prevalence among 12-15-year-olds in Lithuania between 1983 and 2005.

OBJECTIVE: To analyze the dynamics of prevalence and severity of dental caries among 12- and 15-year-old schoolchildren in six regions of Lithuania. MATERIAL AND METHODS: A total of 5910 schoolchildren aged 12 and 15 years were examined. Dental caries was diagnosed according to the criteria of World Health Organization. The prevalence of dental caries was calculated by dividing the number of children with caries by the number of all children examined and expressed as percentage. Severity of dental caries was described by DMF-T index. DMF-T indices of individual persons as well as each age group were determined. Oral hygiene was evaluated by a simplified oral hygiene index. Fluoride concentration in Kretinga was 1.6-2.2 ppm; in the other regions, it varied between 0.2 to 0.4 ppm. RESULTS: The prevalence of dental caries among 12-year-olds was 88.4% in 1983 and 85.5% in 2005; among 15-year-olds, it was 95.5% and 92.9%, respectively. Mean DMF-T score decreased from 4.5 (in 1983) to 3.7 (in 2005) among 12-year-olds and from 6.4 (in 1983) to 5.6 (in 2005) among 15-year-olds. Oral hygiene index decreased from 1.69 in 1983 to 1.34 in 2005 among 12-year-olds and from 1.46 to 1.22 among 15-year-olds, respectively. CONCLUSIONS: A tendency towards decrease in the prevalence and severity of dental caries was observed, when caries prevention program was running. Correlation between oral hygiene and DMF-T was observed in both age groups. Decreased prevalence and intensity of dental caries among 12- and 15-year-olds were associated with improved oral hygiene, usage of fluoride toothpaste, and fluoride content in drinking water.

Lysozyme and microbiota in relation to gingivitis and periodontitis.

BACKGROUND: The aim of this study was to investigate associations between the immune component of the oral cavity, lysozyme, in gingival crevicular fluid and unstimulated saliva, and colonization dynamics of periodontopathogenic bacteria from supra- and subgingival plaque samples in patients with gingivitis or periodontitis. MATERIAL/METHODS: Lysozyme in crevicular fluid and unstimulated saliva, and bacteria in supra- and subgingival plaque samples were assessed in 84 samples from 28 patients with gingivitis, 96 samples from 32 patients with periodontitis, and 72 samples from 24 donors with intact periodontium and free of internal disease. Lysozyme activity was determined spectrophotometrically. The micro-IDent plus assay was used to detect 6 periodontopathogenic bacteria plaque samples. RESULTS: Lysozyme activity in crevicular fluid in the gingivitis and periodontitis groups was significantly greater than that in the donor group, but lysozyme activity in unstimulated saliva was less than that in the donor group. Peptostreptococcus micros, Fusobacterium periodontium and Campylobacter rectus were predominant in subgingival plaque samples in the periodontitis group compared to the donor group (P<0.001), and Eubacterium nodatum and Eikenella corrodens were predominant in the gingivitis group compared to the donor group (P<0.001). CONCLUSIONS: Lysozyme activity in crevicular fluid and in unstimulated saliva correlated with periodontal pocket depth in donors and in patients with gingivitis or periodontitis (specificity and sensitivity were both 100%). These findings indicate that infection with P. micros, F. periodontium, E. nodatum, E. corrodens, and C. rectus may be an important indicator of inflammatory periodontal disease development.

[Microbiological and biochemical characteristics of inflammatory tissues in the periodontium]. / Uzdegiminiu apydancio audiniu mikrobiologines ir biochemines savybes.

OBJECTIVE: To investigate bacterial populations in subgingival and supragingival plaque samples of patients with inflammatory periodontal diseases and activities of the lysosomal enzymes--lysozyme, alkaline phosphatase, and beta-glucuronidase--in peripheral venous blood, in gingival crevicular fluid, and mixed nonstimulated saliva. METHODS AND MATERIALS: The study included 60 patients with inflammatory periodontal diseases without any internal pathology and 24 periodontally healthy subjects. Molecular genetic assay (Micro-IDent plus, Germany) for complex identification of additional six periodontopathic bacteria was applied. The activity of lysozyme was determined turbidimetrically, the activity of alkaline phosphatase--spectrophotometrically with a "Monarch" biochemical analyzer, the activity beta-glucuronidase--according to the method described by Mead et al. and modified by Strachunskii. RESULTS: A statistically significant association between clinical and bacteriological data was found in the following cases: gingival bleeding in the presence of Eubacterium nodatum, Eikenella corrodens, Capnocytophaga spp. (P<0.01); pathological periodontal pockets in the presence of Peptostreptococcus micros (alpha< or =0.05 and beta< or =0.2), Fusobacterium nucleatum (alpha< or =0.05 and beta< or =0.2), Campylobacter rectus (alpha< or =0.05 and beta< or =0.2), and Capnocytophaga spp. (P<0.05); and satisfactory oral hygiene in the presence of all microorganisms investigated (P<0.05). The activity of lysozyme in gingival crevicular fluid and mixed nonstimulated saliva indicates the severity of periodontal inflammation. Based on clinical data, in assessing the amount of lysozyme in mixed nonstimulated saliva, sensitivity and specificity of 100% was found. Increased activities of lysozyme, alkaline phosphatase, and beta-glucuronidase were found in peripheral venous blood of patients with inflammatory periodontal disease as compared to control group. CONCLUSIONS: The main principles of the treatment of periodontal inflammatory diseases should be based on microorganism elimination, creation of individual treatment means affecting microflora in the mouth and immune system of macroorganisms.

Secretory function of neutrophilic leukocytes of the patients with periodontal diseases.

Aim of study was to examine periodontal status among 20 44 year old patients and to study the secretory function of peripheral venous blood neutrophilic leukocytes (NL) exposed to various antigens and alkaline phosphatase (AP) activity in gingival crevicular fluid (GCF) in patients suffering from gingivitis and periodontitis. Clinically were determined Russell's periodontal index (PI). Secretory function of NL affected by opsonized zymosane, non-opsonized E. coli was examined in 77 patients with gingivitis and periodontitis, and in 35 donors, free of internal diseases, by means of beta-glucuronidase (beta-GD), lysozyme (LZ). NL secreted higher levels of beta-GD in incubation medium in patients with periodontitis (p < or = 0.001) subject to degree of periodontal lesion. NL affected by various antigens secreted higher levels of LZ into non-cellular matrix in patients with gingivitis and periodontitis comparing to control environment in analogous groups. Data obtained from this study suggest that in patients with periodontitis response of NL to bacterial stimuli is specific and subject to the degree of periodontal lesion. Our study showed a significant difference of AP activity in GCF subject to pocket depth and degree of periodontal lesion. Once NL are exposed to corpuscules prone to phagocytosis, an increase in secretion of beta-GD and LZ can be explained by overall increase in secretion of NL lysosomic enzymes, thus disclosing the mechanism of inflammatory periodontal tissue damage.