Salivary, blood and plasma nitrite concentrations in periodontal patients and healthy individuals before and after periodontal treatment.

BACKGROUND: To date, no study has employed ozone-based reductive chemiluminescence to compare nitrite concentration in the saliva of periodontal disease (PD) and healthy individuals or in the various blood compartments of the same individuals before and after periodontal treatment. We evaluated nitrite concentrations in whole, submandibular, and parotid saliva, as well as in whole blood, erythrocytes, and plasma of healthy volunteers and patients with chronic periodontitis. METHODS: Data obtained for the PD and control groups were compared before and 3 months after periodontal therapy. RESULTS: At baseline, stimulated whole saliva nitrite concentration was lower in PD patients (mean=57.3 ± 9.8 µmol/L) as compared with healthy individuals (92.5 ± 13.6 µmol/L, P<0.05). PD and periodontal treatment did not affect submandibular or parotid saliva nitrite concentrations. PD patients presented higher baseline whole blood nitrite concentration (238.4 ± 45.7 µmol/L) as compared with values recorded 3 months after therapy (141.3 ± 20.1 nmol/L, P<0.05). PD patients' erythrocytes exhibited higher baseline nitrite concentration (573.1 ± 97.8 nmol/L) as compared with three months after therapy (298.7 ± 52.1 nmol/L, P<0.05). Again, PD and PD treatment did not impact plasma nitrite concentration. CONCLUSIONS: PD patients had lower nitrite concentration in whole saliva, and this situation remained unchanged after periodontal treatment. Nevertheless, erythrocytes and whole blood nitrite levels diminished after periodontal treatment.

Technique of Framework Cemented on Prepared Abutments to Obtain Passive Fit at Fixed Complete Denture: A 2-Year Follow-Up Report

The passive fit of implant-supported dentures is fundamental to the rehabilitation success due the absence of the periodontal ligament in osseointegrated implants. Many techniques to obtain passive fit have been reported in the literature, some inaccessible for the clinicians and dental laboratories. This case report presents a technique to fabricate fixed complete dentures aiming at obtain passive fit with reduced time and cost, but without demerit for the aesthetics, function and longevity. A 40-year-old woman was referred for treatment presenting some teeth in the maxilla and an edentulous mandible, reporting eating problems related to instability and little retention of the mandibular complete denture. Treatment based on the reverse planning was performed to guide the rehabilitation with a complete mandibular fixed complete denture and maxillary occlusal plane adjustment. The framework of the fixed complete denture was manufactured luting a cast metal bar above the prepared titanium cylinder abutments using resin cement. The aim of this technique was to obtain a fixed complete denture with passive fit presenting positive esthetic and functional outcomes after 2 years of follow-up.

A adaptação passiva de próteses implantossuportadas é fundamental para o sucesso da reabilitação devido à inexistência de ligamento periodontal em implantes osseointegrados. Inúmeras técnicas de confecção da infraestrutura destas próteses tem sido relatadas na literatura, algumas inacessíveis para os clínicos e laboratórios de prótese. Este relato de caso apresenta uma técnica para confecção de próteses totais fixas visando obtenção de adaptação passiva com tempo e custo reduzido, porém sem demérito à estética, função e longevidade. Uma paciente de 40 anos se apresentou para tratamento apresentando alguns dentes na maxila e mandíbula edêntula, relatando dificuldades na mastigação relacionados a instabilidade e falta de retenção da prótese total inferior. Foi realizado um planejamento reverso para orientar a reabilitação com prótese total mandibular fixa e adequação do plano oclusal da maxila. A infraestrutura da prótese total fixa foi confeccionada pela cimentação de uma barra metálica em cilindros de titânio preparados com cimento resinoso. O objetivo desta técnica foi obter uma prótese total fixa com adaptação passiva apresentando resultados positivos em termos de estética e função após 2 anos de acompanhamento.

Technique of framework cemented on prepared abutments to obtain passive fit at fixed complete denture: a 2-year follow-up report.

The passive fit of implant-supported dentures is fundamental to the rehabilitation success due the absence of the periodontal ligament in osseointegrated implants. Many techniques to obtain passive fit have been reported in the literature, some inaccessible for the clinicians and dental laboratories. This case report presents a technique to fabricate fixed complete dentures aiming at obtain passive fit with reduced time and cost, but without demerit for the aesthetics, function and longevity. A 40-year-old woman was referred for treatment presenting some teeth in the maxilla and an edentulous mandible, reporting eating problems related to instability and little retention of the mandibular complete denture. Treatment based on the reverse planning was performed to guide the rehabilitation with a complete mandibular fixed complete denture and maxillary occlusal plane adjustment. The framework of the fixed complete denture was manufactured luting a cast metal bar above the prepared titanium cylinder abutments using resin cement. The aim of this technique was to obtain a fixed complete denture with passive fit presenting positive esthetic and functional outcomes after 2 years of follow-up.

Interleukin 4 haplotypes of susceptibility to chronic periodontitis are associated with IL-4 protein levels but not with clinical outcomes of periodontal therapy.

Different IL4 haplotypes were associated to susceptibility to/or protection against chronic periodontitis (CP). The aim of this study was to investigate if individuals carrying different haplotypes would present differences in clinical periodontal parameters and in the IL-4 levels at baseline, 45 and 90 days after non-surgical periodontal therapy. 62 patients were subdivided: genetically protected without CP (PH), genetically protected with CP (PCP), genetically susceptible with CP (SCP), genetically susceptible without CP (healthy) (SH). Clinical examination and gingival crevicular fluid (GCF) collection were performed for all patients, and IL-4 levels were measured by ELISA. At baseline, higher values for plaque index (PI, p = 0.013), gingival index (GI, p = 0.005) were observed for the SCP group in comparison to the PCP group but not after the completion of periodontal therapy. 45 and 90 days after the non-surgical therapy, PCP demonstrated significantly higher IL-4 levels than the SCP (p = 0.000002). Correlation analysis showed different results between clinical parameters and IL-4 production or GCF volume for groups with different genetic loads. The IL4 gene which was previously associated with susceptibility to CP was related with differences in the IL-4 protein levels in the GCF. However, independent of genetic carriage, individuals responded similarly to this therapy.

Salivary MMPs, TIMPs, and MPO levels in periodontal disease patients and controls.

BACKGROUND: Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases with an important role in physiological and pathological remodeling. Their activity is regulated by tissue inhibitors of matrix metalloproteinases (TIMPs). Excess MMPs and myeloperoxidase (MPO) activity have been associated with loss of tooth supporting tissues in periodontal disease (PD). We investigate the changes in salivary MMP-8, MMP-9, TIMP-1, TIMP-2, and MPO concentrations during PD treatment and compare results with plasma levels. METHODS: MMP-8, MMP-9, TIMP-1 and TIMP-2 were analyzed by ELISA. Gelatinolytic activity of MMP-9 forms was determined by zymography, and the MPO activity was determined by colorimetric assay. RESULTS: Subjects were divided into 2 groups: PD and control, which were further divided into 2 subgroups each, namely PD before (PB) and after 3 months (PA) of non-surgical periodontal therapy, and healthy volunteers at baseline (CB) and 3months after baseline (CA). Subgroup PA presented lower gelatinolytic activity and MMP-8 and TIMP-2 concentrations in the saliva compared with PB (p<0.05). The MPO activity was higher in PB compared with CB (p<0.05). There were significant correlations between the gelatinolytic activity of the saliva and MMP-8 and MMP-9 plasma levels. There was a significant correlation between plasma and saliva TIMP-2 levels. CONCLUSION: These results suggest attenuation of some inflammatory markers in the saliva and plasma after PD treatment. Moreover, correlations between salivary and plasma levels exist for some of these markers.

Haplotypes of susceptibility to chronic periodontitis in the Interleukin 8 gene do not influence protein level in the gingival crevicular fluid.

OBJECTIVE: Previously, we identified that the ATC/TTC haplotype formed by polymorphisms in the Interleukin-(IL)8 gene conferred susceptibility to chronic periodontitis (CP). The aim of the study was to investigate whether the IL8 haplotype ATC/TTC was associated with the volume of gingival crevicular fluid (GCF), the concentration of interleukin IL-8 in the GCF, as well as periodontal conditions in patients with CP in comparison to controls without CP. METHODS: Seventy-nine individuals (CP: n=41, controls: n=38) were grouped according to the presence (susceptible for CP) or absence (not susceptible for CP) of the IL8 ATC/TTC haplotype. After periodontal clinical evaluation, they were subdivided by the presence or absence of CP. GCF was collected from each patient and the IL-8 levels were determined by ELISA. The GCF volume of each subject was measured by means of a calibrated electronic device. Comparisons of means between carriers and non-carriers of the ATC/TTC haplotype were evaluated using the Mann-Whitney test. Linear regression and stepwise linear regression analysis were used to analyse the association of the GCF volume with potential covariates and their contribution for the phenotype. RESULTS: We did not find significant differences of both periodontal conditions and IL-8 concentration in the GCF of patients with the presence or absence of the IL8 ATC/TTC haplotype. However, the GCF volume was significantly higher amongst the patients affected by CP that are absent for the IL8 ATC/TTC haplotype. In addition, linear regression analysis showed a statistically significant association between GCF volume and CP, IL8 haplotype ATC/TTC and IL-8 concentration. CONCLUSIONS: The IL8 haplotype of susceptibility to CP was neither associated with IL-8 cytokine levels nor with clinical periodontal parameters. Also, CP, IL8 haplotype and IL-8 concentration showed a positive association with the GCF volume levels in the studied patients.

Myeloperoxidase activity is increased in gingival crevicular fluid and whole saliva after fixed orthodontic appliance activation.

INTRODUCTION: Orthodontic tooth movement uses mechanical forces that result in inflammation in the first days. Myeloperoxidase (MPO) is an enzyme found in polymorphonuclear neutrophil (PMN) granules, and it is used to estimate the number of PMN granules in tissues. So far, MPO has not been used to study the inflammatory alterations after the application of orthodontic tooth movement forces. The aim of this study was to determine MPO activity in the gingival crevicular fluid (GCF) and saliva (whole stimulated saliva) of orthodontic patients at different time points after fixed appliance activation. METHODS: MPO was determined in the GCF and collected by means of periopaper from the saliva of 14 patients with orthodontic fixed appliances. GCF and saliva samples were collected at baseline, 2 hours, and 7 and 14 days after application of the orthodontic force. RESULTS: Mean MPO activity was increased in both the GCF and saliva of orthodontic patients at 2 hours after appliance activation (P <0.02 for all comparisons). At 2 hours, PMN infiltration into the periodontal ligament from the orthodontic force probably results in the increased MPO level observed at this time point. CONCLUSIONS: MPO might be a good marker to assess inflammation in orthodontic movement; it deserves further studies in orthodontic therapy.

Comparison between micro- and macrosurgical techniques for the treatment of localized gingival recessions using coronally positioned flaps and enamel matrix derivative.

BACKGROUND: The aim of this study is to compare the macro- and microsurgery techniques for root coverage using a coronally positioned flap (CPF) associated with enamel matrix derivative (EMD). METHODS: Thirty patients were selected for the treatment of localized gingival recessions (GRs) using CPF associated to EMD. Fifteen patients were randomly assigned to the test group (TG), and 15 patients were randomly assigned to the control group (CG). The microsurgical approach was performed in the TG, and the conventional macrosurgical technique was performed in the CG. The clinical parameters evaluated before surgery and after 6 months were GR, probing depth, relative clinical attachment level, width of keratinized tissue (WKT), and thickness of keratinized tissue (TKT). The discomfort evaluation was performed 1 week postoperative. RESULTS: There were no statistically significant differences between groups for all parameters at baseline. At 6 months, there was no statistically significant difference between the techniques in achieving root coverage. The percentage of root coverage was 92% and 83% for TG and CG, respectively. After 6 months, there was a statistically significant increase of WKT and TKT in TG only. Both procedures were well tolerated by all patients. CONCLUSIONS: The macro- and microsurgery techniques provided a statistically significant reduction in GR height. After 6 months, there was no statistically significant difference between the techniques regarding root coverage, and the microsurgical technique demonstrated a statistically significant increase in WKT and TKT.

Gingival crevicular fluid levels of MMP-8, MMP-9, TIMP-2, and MPO decrease after periodontal therapy.

BACKGROUND: This study aimed at comparing the levels of matrix metalloproteinase (MMP)-8, tissue Inhibitor of MMPs (TIMP)-1 and TIMP-2, Myeloperoxidase (MPO), and MMP-9 in the gingival crevicular fluid (GCF) of chronic periodontitis (CP) patients and controls at baseline and 3 months after non-surgical therapy. MATERIALS AND METHODS: GCF was collected from one site of 15 control subjects and 27 CP patients. MMP-8, MMP-9, TIMP-1, and TIMP-2 were determined by Enzyme-linked immunoabsorbent assay; different forms of MMP-9, by gelatin zymography; and MPO, colorimetrically. RESULTS: At baseline, higher levels of MMP-8, TIMP-2, MPO, and the 87 kDa-MMP-9 were found in patients compared with controls (p<0.001), and these molecules decreased after therapy (p<0.03). There were no differences between the groups with respect to the higher molecular forms of MMP-9 (180, 130, 92 kDa) or total MMP-9 at baseline. No differences were observed in TIMP-1 levels. In controls, decreased levels of TIMP-2 and the higher molecular forms of MMP-9 (180, 130, 92 kDa) were found 3 months after therapy compared with baseline (p<0.01). CONCLUSIONS: Higher levels of MMP-8, TIMP-2, MPO, and 87 kDa MMP-9 were found in the GCF of patients compared with controls, and these markers decreased 3 months after periodontal therapy.

Circulating matrix metalloproteinase-8 (MMP-8) and MMP-9 are increased in chronic periodontal disease and decrease after non-surgical periodontal therapy.

BACKGROUND: Periodontal disease shares risk factors with cardiovascular diseases and other systemic inflammatory diseases. The present study was designed to assess the circulating matrix metalloproteinases (MMPs) from chronic periodontal disease patients and, subsequently, after periodontal therapy. METHODS: We compared the plasma concentrations of MMP-2, MMP-3, MMP-8, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2, and total gelatinolytic activity in patients with periodontal disease (n=28) with those of control subjects (n=22) before and 3 months after non-surgical periodontal therapy. RESULTS: Higher plasma MMP-3, MMP-8, and MMP-9 concentrations were found in periodontal disease patients compared with healthy controls (all P<0.05), whereas MMP-2, TIMP-1, and TIMP-2 levels were not different. Treatment decreased plasma MMP-8 and MMP-9 concentrations by 35% and 39%, respectively (both P<0.02), while no changes were found in controls. MMP-2, MMP-3, TIMP-1, and TIMP-2 remained unaltered in both groups. Plasma gelatinolytic activity was higher in periodontal disease patients compared with controls (P<0.001) and decreased after periodontal therapy (P<0.05). CONCLUSIONS: This study showed increased circulating MMP-8 and MMP-9 levels and proteolytic activity in periodontal disease patients that decrease after periodontal therapy. The effects of periodontal therapy suggest that it may attenuate inflammatory chronic diseases.

Different circulating metalloproteinases profiles in women with migraine with and without aura.

BACKGROUND: We compared the circulating levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, and MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in migraine patients without aura (MWA) and in migraine patients with aura (MA) with those found in healthy subjects (controls). METHODS: We studied 80 migraine (40 MWA and 40 MA) women and 40 controls. Pro-MMP-2 levels were determined by zymography and MMP-9, TIMP-1, and TIMP-2 levels were determined by ELISA. RESULTS: While we found similar TIMP-2 levels, higher plasma pro-MMP-2 and pro-MMP-2/TIMP-2 ratios were found in MWA and MA patients compared with controls (P<0.05). Higher TIMP-1 levels and lower MMP-9/TIMP-1 ratios were found in MA, but not in MWA, patients compared with controls (P<0.05). We found no significant differences when patients without headache attack were compared with patients having a headache attack (all P<0.05). CONCLUSIONS: We showed an increased net MMP-2 activity in MWA and MA. The increased MMP-9/TIMP-1 ratios in MWA patients contrast with the lower MMP-9/TIMP-1 ratios in MA patients and may reflect pathophysiological differences between these conditions.

Circulating interleukin-6 and high-sensitivity C-reactive protein decrease after periodontal therapy in otherwise healthy subjects.

BACKGROUND: Periodontal disease has been associated with many chronic inflammatory systemic diseases, and a common chronic inflammation pathway has been suggested for these conditions. However, few studies have evaluated whether periodontal disease, in the absence of other known inflammatory conditions and smoking, affects circulating markers of chronic inflammation. This study compared chronic inflammation markers in control individuals and patients with periodontal disease and observed whether non-surgical periodontal therapy affected inflammatory disease markers after 3 months. METHODS: Plasma and serum of 20 controls and 25 patients with periodontal disease were obtained prior to and 3 months after non-surgical periodontal therapy. All patients were non-smokers, they did not use any medication, and they had no history or detectable signs and symptoms of systemic diseases. Periodontal and systemic parameters included probing depth, bleeding on probing, clinical attachment level, hematologic parameters, as well as the following inflammatory markers: interleukin (IL)-6, high-sensitivity C-reactive protein (hs-CRP), CD40 ligand, monocyte chemoattractant protein (MCP)-1, soluble P-selectin (sP-selectin), soluble vascular adhesion molecule (sVCAM)-1, and soluble intercellular adhesion molecule (sICAM)-1. RESULTS: There were no differences in the hematologic parameters of the patients in the control and periodontal disease groups. Among the tested inflammatory markers, IL-6 concentrations were higher in the periodontal disease group at baseline compared to the controls (P = 0.006). Therapy was highly effective (P <0.001 for all the analyzed clinical parameters), and a decrease in circulating IL-6 and hs-CRP concentrations was observed 3 months after therapy (P = 0.001 and P = 0.006, respectively). Our results also suggest that the CD40 ligand marker may have been different in the control and periodontal disease groups prior to the therapy (P = 0.009). CONCLUSIONS: In apparently otherwise healthy patients, periodontal disease is associated with increased circulating concentrations of IL-6 and hs-CRP, which decreased 3 months after non-surgical periodontal therapy. With regard to the CD40 ligand, MCP-1, sP-selectin, sVCAM-1, and sICAM-1, no changes were seen in the periodontal disease group between baseline and 3 months after therapy.

Assessment of matrix metalloproteinase (MMP)-2, MMP-8, MMP-9, and their inhibitors, the tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in obese children and adolescents.

OBJECTIVES: To compare the circulating levels of matrix metalloproteinase (MMP)-8, pro-MMP-2, pro-MMP-9, and total MMP-9, their endogenous inhibitors, the tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2, and the MMP-8/TIMP-1, MMP-9/TIMP-1, and MMP-2/TIMP-2 ratios in normotensive obese children and adolescents with those found in non obese children and adolescents. DESIGN AND METHODS: We studied 40 obese and 40 non obese (controls) children and adolescents in this cross-sectional study. MMP and TIMP concentrations were measured in plasma samples by gelatin zymography and ELISA. RESULTS: Obese children and adolescents had higher circulating MMP-8 concentrations, lower plasma TIMP-1 concentrations, and higher MMP-8/TIMP-1 ratios than non obese controls (P<0.05). We found no differences in pro-MMP-9 or total MMP-9 levels, or in MMP-9/TIMP-1 ratios between groups (P>0.05). While we found no significant differences in pro-MMP-2 levels (P>0.05) obese subjects had higher TIMP-2 concentrations and lower pro-MMP-2/TIMP-2 ratios (P<0.05) than non obese controls. CONCLUSIONS: In conclusion, we found evidence indicating higher net MMP-8 (but not MMP-9 and MMP-2) activity in childhood obesity. The increased MMP-8 levels found in obese children suggest a possibly relevant pathophysiological mechanism that may be involved in the increase of cardiovascular risk associated with childhood obesity.

Increased circulating levels of matrix metalloproteinase (MMP)-8, MMP-9, and pro-inflammatory markers in patients with metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS) predisposes to cardiovascular complications. Increased concentrations of pro-inflammatory mediators and imbalanced concentrations of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) may reflect the pathophysiology of MetS. We compared the circulating levels of MMPs, TIMPs, and inflammatory mediators in MetS patients with those found in healthy controls. METHODS: We studied 25 healthy subjects and 25 MetS patients. The plasma levels of pro-MMP-2 and pro-MMP-9 were determined by gelatin zymography. The plasma concentrations of MMP-8, MMP-3, TIMP-1, TIMP-2, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), intercellular adhesion molecule (sICAM-1), and sP-selectin were measured by ELISA kits. RESULTS: We found higher sP-selectin, sICAM-1, MCP-1, and IL-6 (all P<0.05) concentrations in MetS patients compared with healthy controls. No differences in pro-MMP-2, MMP-3, and TIMP-2 levels were found (all P>0.05). However, we found higher pro-MMP-9, MMP-8, and TIMP-1 levels in MetS patients compared with healthy controls (all P<0.05). CONCLUSIONS: Patients with MetS have increased circulating concentrations of pro-MMP-9, MMP-8, and TIMP-1 that are associated with increased concentrations of pro-inflammatory mediators and adhesion molecules. These findings suggest that MMPs may have a role in the increased cardiovascular risk of MetS patients. Pharmacological interventions targeting MMPs, especially MMP-9 and MMP-8 deserve further investigation in MetS patients.

Functional polymorphisms in the promoter of the matrix metalloproteinase-9 (MMP-9) gene are not linked with significant plasma MMP-9 variations in healthy subjects.

BACKGROUND: Matrix metalloproteinase-9 (MMP-9) is involved in the degradation of the extracellular matrix during physiological and pathological processes. Two functional polymorphisms [C(-1562)T and microsatellite (CA)13-25] in the promoter region of the MMP-9 gene have been associated with several diseases. The aim of this study was to examine whether these MMP-9 polymorphisms and haplotypes are linked with plasma MMP-9 variations in healthy subjects. METHODS: We studied 177 healthy male white volunteers (age range 20-55 years) who were non-smokers and not taking any medication. Genomic DNA was extracted from whole blood and genotypes for the C(-1562)T and the microsatellite (CA)n polymorphisms were determined. MMP-9 levels were measured in plasma samples by gelatin zymography. RESULTS: The frequency of the alleles C and T for the C(-1562)T polymorphism were 90% and 10%, respectively. The frequency of the alleles with less than 21 CA repeats (L) and with 21 repeats or higher (H) were 47% and 53%, respectively. We found no differences in plasma MMP-9 levels among the genotype groups or among different haplotypes (all p>0.05). CONCLUSIONS: These findings suggest that functional polymorphisms in the promoter of the MMP-9 gene are not linked with significant plasma MMP-9 variations in healthy subjects.

Immediate placement of implants into periodontally infected sites in dogs. Part 2: A fluorescence microscopy study.

PURPOSE: Polychromatic sequence labeling of bone was used to study the effect of periodontal infection on the immediate placement of Frialit-2 implants. MATERIALS AND METHODS: In the surgical first phase, periodontitis was induced with ligatures involving the mandibular premolars of 5 mongrel dogs, and the contralateral teeth were used as controls (received only prophylaxis). After 3 months, the second phase was initiated and 40 implants were placed in the alveoli of both experimental and control teeth. During the healing period, fluorescent bone markers were injected to study bone formation around the implants. The dyes were injected in the following sequence: oxytetracycline hydrochloride at 3 days after implant placement, calcein green 4 weeks after implant placement, oxytetracycline 8 weeks after implant placement, and alizarin red S 3 days before sacrifice. Following a healing period of 12 weeks, the animals were euthanized and the hemimandibles were removed, dissected, fixed, and prepared for histomorphometic analysis of the percentage of each bone marker present. RESULTS: Fluorescence microscopy showed a similar sequence of bone remodeling (Mann-Whitney test) for both groups: experimental group, 9% bone formation at 3 days, 29% at 4 weeks, 21.6% at 8 weeks, and 52% at 12 weeks; control group, 14% at 3 days, 35.2% at 4 weeks, 32.3% at 8 weeks, and 45.8% at 12 weeks. DISCUSSION: Remodeling in both groups had similar characteristics in the degree of bone formation. CONCLUSIONS: It was concluded that periodontal disease does not affect bone remodeling around immediate implants. Although the healing in periodontally infected sites was slower initially, it reached the levels of the non-diseased sites after 12 weeks.

Immediate placement of implants into periodontally infected sites in dogs: a histomorphometric study of bone-implant contact.

PURPOSE: The placement of implants allows for re-establishment of function and esthetics following tooth loss. Immediate implant placement is a relatively recent procedure and has advantages, such as reduced number of surgical procedures, preservation of alveolar bone, reduction of cost and period of edentulism, and increased patient acceptance. However, there are some specific contraindications for the technique, such as the presence of an infection caused by periodontal disease and periapical lesions. The objective of this study was to evaluate the percentage of bone-implant contact of immediate implants placed in periodontally infected sites. MATERIALS AND METHODS: In the first phase, periodontitis was induced with ligatures in the mandibular premolars of 5 mongrel dogs, using the contralateral teeth as controls (received prophylaxis only). After 3 months, in the second phase of the study, 40 implants were placed in the alveoli of both experimental and control teeth. After a healing period of 12 weeks, the animals were euthanized, and the hemimandibles were removed, dissected, fixed, and prepared for histomorphometric analysis of percentage of bone-implant contact. The Mann-Whitney test was used for statistical analysis. RESULTS: The results of the histomorphometric analysis indicated mean bone-implant contact of 62.4% in the control group and 66.0% in the experimental group, a difference that was not statistically significant. DISCUSSION: Histomorphometric results revealed similar bone-implant contact in both groups, with no signs of infection. CONCLUSIONS: It was concluded that periodontally infected sites may not be a contraindication for immediate implantation in this animal model system, if adequate pre- and postoperative care is taken.

Immediate placement of implants into periodontally infected sites in dogs: a histomorphometric study of bone-implant contact / Posicionamento imediato de implantes em áreas infectadas periodonticamente em cachorros: um estudo histomorfométrico de contato implante-ósseo

Purpose: The placement of implants allows for re-establishment of function and esthetics following tooth loss. Immediate implant placement is a relatively recent procedure and has advantages, such as reduced number of surgical procedures, preservation of alveolar bone, reduction of cost and period of edentulism, and increased patient acceptance. However, there are some specific contraindications for the technique, such as the presence of an infection caused by periodontal disease and periapical lesions. The objective of this study was to evaluate the percentage of bone-implant contact of immediate implants placed in periodontally infected sites. Materials and Methods: In the first phase, periodontitis was induced with ligatures in the mandibular premolars of 5 mongrel dogs, using the contralateral teeth as controls (received prophylaxis only). After 3 months, in the second phase of the study, 40 implants were placed in the alveoli of both experimental and control teeth. After a healing period of 12 weeks, the animals were euthanized, and the hemimandibles were removed, dissected, fixed, and prepared for histomorphometric analysis of percentage of bone-implant contact. The Mann- Whitney test was used for statistical analysis. Results: The results of the histomorphometric analysis indicated mean bone-implant contact of 62.4 percent in the control group and 66.0 percent in the experimental group, a difference that was not statistically significant. Discussion: Histomorphometric results revealed similar bone-implant contact in both groups, with no signs of infection. Conclusions: It was concluded that periodontally infected sites may not be a contraindication for immediate implantation in this animal model system, if adequate pre- and postoperative care is taken