Francisco H. Nociti

Interleukin-8 Gene Promoter Polymorphism (rs4073) May Contribute to Chronic Periodontitis

BACKGROUND The proinflammatory chemokine interleukin (IL)-8 is important in the regulation of the inflammatory response. Analyses of the single nucleotide polymorphism (SNP) reference sequence (rs) 4073 showed that the A allele upregulated IL-8 levels after stimulation with lipopolysaccharides. We investigated the association of the SNP rs4073 with chronic periodontitis. METHODS Genotyping was performed by a standard polymerase chain reaction-restriction fragment length polymorphism assay in 289 genomic DNA samples of healthy control subjects and patients with chronic periodontitis; analyses were adjusted by multivariate logistic regression modeling. A real-time polymerase chain reaction performance was used to detect levels of the IL-8 mRNA. RESULTS The analysis pointed to a statistically significant association of chronic periodontitis with the heterozygous TA genotype (P = 0.001); the results showed an increase in the frequency of the A allele in the diseased group (36% in the control group versus 48% in the periodontitis group). The higher levels of the IL-8 mRNA were found in the periodontitis group, mainly in individuals who presented the TA genotype (P = 0.03). CONCLUSION The SNP rs4073 was associated with chronic periodontitis in non-smoker Brazilian subjects because the frequency of the A allele was higher in the disease group than in the control group, and the TA genotype was associated with increased levels of IL-8 mRNA transcripts.

Full-Mouth Ultrasonic Debridement Associated With Amoxicillin and Metronidazole in the Treatment of Severe Chronic Periodontitis

BACKGROUND The purpose of this study was to evaluate the adjunctive clinical, microbiologic, and immunologic effects of the systemic administration of amoxicillin and metronidazole in the full-mouth ultrasonic debridement of patients with severe chronic periodontitis. METHODS Twenty-five patients presenting at least eight teeth with probing depth (PD) > or =5 mm and bleeding on probing (BOP) were selected and randomly assigned to full-mouth ultrasonic debridement + placebo (control group) or full-mouth ultrasonic debridement + amoxicillin and metronidazole (test group). The clinical outcomes evaluated were visible plaque index, BOP, position of the gingival margin, relative attachment level (RAL), and PD. Real-time polymerase chain reaction (PCR) was used for quantitative analysis of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, and Tannerella forsythia (previously T. forsythensis). The enzyme-linked immunosorbent assay (ELISA) technique permitted the detection of prostaglandin E(2,) interleukin-1beta, and interferon-gamma levels in gingival crevicular fluid. All parameters were evaluated at baseline and at 3 and 6 months post-treatment. RESULTS At 6 months, the test treatment resulted in lower BOP and an additional reduction (0.83 mm) in PD (P <0.05). Data also showed RAL gain > or =2 mm at 43.52% of sites in control patients compared to 58.03% of sites in test patients (P <0.05). However, both groups had similar mean RAL gain (1.68 and 1.88 mm for the control and test groups, respectively). Real-time PCR and ELISA failed to identify significant differences between the groups. CONCLUSIONS Both treatments resulted in significant clinical improvements; however, there was a slight, but significantly greater, improvement in BOP and the percentage of sites with PD > or =5 mm exhibiting RAL gain > or =2 mm in the test group. Nevertheless, no improvement in the microbiologic or immunologic outcome was observed with the adjunctive use of systemic amoxicillin and metronidazole.

Photodynamic Therapy During Supportive Periodontal Care: Clinical, Microbiologic, Immunoinflammatory, and Patient-Centered Performance in a Split-Mouth Randomized Clinical Trial

BACKGROUND This study investigates the effect of photodynamic therapy (PDT) as monotherapy during supportive periodontal therapy. METHODS A split-mouth, randomized controlled trial was conducted in patients with chronic periodontitis (N = 22) presenting at least three residual pockets (probing depth [PD] ≥5 mm with bleeding on probing [BOP]). The selected sites randomly received the following: 1) PDT; 2) photosensitizer (PS); or 3) scaling and root planing (SRP). At baseline and 3 and 6 months, clinical, microbiologic (real-time polymerase chain reaction analyses), cytokine pattern (multiplexed bead immunoassay), and patient-centered (regarding morbidity) evaluations were performed. RESULTS All therapies promoted similar improvements in clinical parameters throughout the study (P <0.05), except that BOP was not reduced in the PS protocol (P >0.05). Lower levels of Aggregatibacter actinomycetemcomitans were observed in the PDT and SRP protocols at 3 months when compared with the PS protocol (P <0.05). An inferior frequency detection of Porphyromonas gingivalis was observed in the PDT protocol at 3 and 6 months and in the SRP protocol at 6 months from baseline (P <0.05). In addition, PDT protocol presented inferior frequency of P. gingivalis at 3 months when compared with the other therapies (P <0.05). Only patients in the PDT protocol exhibited augmented levels of anti-inflammatory interleukin (IL)-4 and reduced proinflammatory IL-1β and IL-6 throughout the study (P <0.05). Intergroup analyses showed reduced IL-10 and increased interferon-γ and IL-1β levels in the PS protocol when compared with the other therapies during follow-ups (P <0.05). No differences in morbidity were observed between the therapies (P >0.05), although the need for anesthesia was higher in SRP-treated sites (P <0.05). CONCLUSION PDT as an exclusive therapy may be considered a non-invasive alternative for treating residual pockets, offering advantages in the modulation of cytokines.

The combination of amoxicillin and metronidazole improves clinical and microbiologic results of one-stage, full-mouth, ultrasonic debridement in aggressive periodontitis treatment.

BACKGROUND The aim of the present study is to assess clinical, microbiologic, and immunologic benefits of amoxicillin/metronidazole (AM) when performing full-mouth ultrasonic debridement (FMUD) in generalized aggressive periodontitis (GAgP) treatment. METHODS Twenty-four GAgP patients were divided into two groups: the FMUD group (n = 12), which received FMUD plus placebo, and the FMUD+AM group (n = 12), which received FMUD and 375 mg amoxicillin plus 250 mg metronidazole for 7 days. The following clinical outcomes were tested: plaque and bleeding on probing indices, pocket probing depth (PD), relative gingival margin position (GMP), and relative clinical attachment level (CAL). Total amount of Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythia (Tf), and gingival crevicular fluid (GCF) concentration of interleukin (IL)-10 and IL-1β were also determined. All clinical, microbiologic, and immunologic parameters were assessed at baseline and at 3 and 6 months post-therapy. The ANOVA/Tukey test was used for statistical analysis (α = 5%). RESULTS Amoxicillin/metronidazole used as an adjunct to the FMUD protocol added clinical and microbiologic benefits to GAgP treatment (P <0.05). FMUD+AM groups presented an additional PD reduction in initially deep PDs at the 3-month follow-up (3.99 ± 1.16 mm and 3.09 ± 0.78 mm for FMUD+AM and FMUD, respectively; P <0.05), a lower number of residual pockets at the 3- and 6-month follow-ups, and a statistical reduction in amounts of Aa (P <0.05). Analysis of Tf and Pg amounts, as well as IL-10 and IL-1β GCF concentrations failed to demonstrate a difference between the groups (P >0.05). CONCLUSION It may be concluded that amoxicillin/metronidazole improves clinical and microbiologic results of FMUD in GAgP treatment.

Semilunar Coronally Positioned Flap or Subepithelial Connective Tissue Graft for the Treatment of Gingival Recession: A 30-Month Follow-Up Study

BACKGROUND The objective of this prospective, controlled clinical trial was to evaluate the long-term outcomes of subepithelial connective tissue graft (SCTG) or semilunar coronally positioned flap (SCPF) for the treatment of Miller Class I gingival recession defects. METHODS Seventeen patients with bilateral Miller Class I gingival recessions (< or =4.0 mm) in maxillary canines or premolars were selected. The recessions were randomly assigned to receive SCPF or SCTG. Recession height (RH), recession width (RW), width of keratinized tissue (WKT), thickness of keratinized tissue (TKT), probing depth (PD), and clinical attachment level (CAL) were measured at baseline and at 6 and 30 months post-surgery. Patient satisfaction with esthetics and root sensitivity was also evaluated. RESULTS The root-coverage outcomes obtained at 6 months were maintained throughout the study. At the 30-month examination, the average percentage of root coverage was 89.25% for SCPF and 96.83% for SCTG (P >0.05); complete root coverage was observed in 58.82% and 88.24% of patients, respectively. SCTG maintained a statistically significant increase in TKT (P <0.05) at 30 months. At this time, there were no significant differences between the two groups with regard to RH, RW, WKT, PD, and CAL. The evaluation of the esthetic outcome by the patient showed a preference for the SCTG treatment. Furthermore, in this group, no patient complained of residual or additional root hypersensitivity. In the SCPF group, three patients had this complaint at 30 months. CONCLUSIONS SCPF and SCTG can be successfully used to treat Class I gingival recession, presenting outcomes with long-term stability. However, patient-oriented outcomes, such as esthetics and root sensitivity, favor SCTG therapy.

Evaluation of Guided Bone Regeneration and/or Bone Grafts in the Treatment of Ligature-induced Peri-implantitis Defects: A Morphometric Study in Dogs

The goal of this study was to evaluate, morphometrically, hard-tissue healing following the treatment of ligature-induced peri-implantitis defects in dogs and guided bone regeneration and/or bone grafts. Five dogs were used, and the mandibular premolars were removed. Three months later, two titanium implants were installed on each side of the mandible, and after another 3 months, abutment connection was performed. Following abutment connection, experimental periimplantitis was induced by placing cotton ligatures in a submarginal position. Ligatures and abutments were removed after 1 month and the bony defects were randomly assigned to one of the following treatments: debridement (DE), debridement plus guided bone regeneration (GBR), debridement plus mineralized bone graft (BG), and debridement plus guided bone regeneration associated with mineralized bone graft (GBR/BG). The dogs were euthanatized after 5 months. Morphometric analysis did not reveal significant differences among the treatments neither with respect to the percentage of bone to implant contact (p = 0.996) nor to the bone area (p = 0.946) within the limits of the threads of the implant. Within the limits of this investigation, there is insufficient evidence to indicate that any of the treatments presented an improved response in dealing with bony defects resulting from peri-implantitis.

Periosteum-Derived Cells as an Alternative to Bone Marrow Cells for Bone Tissue Engineering Around Dental Implants. A Histomorphometric Study in Beagle Dogs

BACKGROUND The aim of this study is to investigate the potential use of periosteum-derived cells (PCs) for tissue engineering in peri-implant defects. METHODS Bone marrow cells (BMCs) and PCs were harvested from seven adult beagle dogs, cultured in vitro, and phenotypically characterized with regard to their osteogenic properties. The animals were then subjected to teeth extraction, and 3 months later, two implant sites were drilled, bone dehiscences created, and dental implants placed. Dehiscences were randomly assigned to one of two groups: PCs (PCs + carrier) and BMCs (BMCs + carrier). After 3 months, the animals were sacrificed and the implants with adjacent hard tissues were processed for undecalcified sections. Bone-to-implant contact, bone fill within the limits of implant threads, and new bone area in a zone lateral to the implant were histometrically obtained. RESULTS In vitro, phenotypic characterization demonstrated that both cell populations presented osteogenic potential, as identified by the mineral nodule formation and the expression of bone markers. Histometrically, an intergroup analysis showed that both cell-treated defects had similar bone fill within the limits of implant threads and bone-to-implant contact (P >0.05), and although a trend toward higher new bone area values was found for the PC group, there was no significant difference between the experimental groups (P >0.05). CONCLUSIONS Periosteal and bone marrow cells presented a similar potential for bone reconstruction. As such, periosteum may be considered as an alternative source of osteogenic cells in implant dentistry.

Surgical Microscope May Enhance Root Coverage With Subepithelial Connective Tissue Graft: A Randomized-Controlled Clinical Trial

BACKGROUND Minimally invasive techniques have broadened the horizons of periodontal plastic surgery to improve treatment outcomes. Thus, the purpose of this clinical trial was to compare root coverage, postoperative morbidity, and esthetic outcomes of subepithelial connective tissue graft (SCTG) technique with or without the use of a surgical microscope in the treatment of gingival recessions. METHODS In this split-mouth study, twenty-four patients with bilateral Millers Class I or II buccal gingival recessions ≥2.0 mm in canines or premolars were selected. Gingival recessions were randomly designated to receive treatment with SCTG with or without the assistance of the surgical microscope (test and control groups, respectively). Clinical parameters evaluated included the following: depth (RH) and width (RW) of the gingival defect, width (WKT) and thickness (TKT) of keratinized tissue, probing depth (PD), and clinical attachment level (CAL). Postoperative morbidity was evaluated by means of an analog visual scale and questionnaire. Patient satisfaction was also evaluated with a questionnaire. Descriptive statistics were expressed as mean ± SD. Repeated-measures analysis of variance was used for examination of differences regarding PD, CAL, and TKT. The Wilcoxon test was used to detect differences between groups and the Friedman test to detect differences within group regarding WKT, RH, and RW. RESULTS The average percentages of root coverage for test and control treatments, after 12 months, were 98.0% and 88.3%, respectively (P <0.05). Complete root coverage was achieved in 87.5% and 58.3% of teeth treated in test and control groups, respectively. For all parameters except recession height, there was an improvement in the final examination but without difference between treatments. For the RH, a lower value was found in the test group compared to the control group (P <0.05). In the test group, all patients were satisfied with the esthetics obtained, and 19 patients (79.1%) were satisfied in the control group. For postoperative morbidity, 14 patients in each of the two treatment groups did not use analgesics for pain control. CONCLUSION Both approaches were capable of producing root coverage; however, use of the surgical microscope was associated with additional clinical benefits in the treatment of teeth with gingival recessions.

Histometric Analysis of the Effect of Enamel Matrix Derivative on the Healing of Periodontal Defects in Rats With Diabetes

BACKGROUND Diabetes mellitus (DM) involves metabolic changes that can negatively influence periodontal tissues, resulting in impaired periodontal repair. There is a lack of information about the outcomes of regenerative approaches under the influence of DM. Enamel matrix derivatives (EMDs) have been used in periodontal regenerative procedures, resulting in improvement of clinical parameters. Thus, the aim of this histomorphometric study is to evaluate the healing of periodontal defects after treatment with EMD under the influence of DM. METHODS Twenty Wistar rats were randomly assigned to two groups: group 1 (G1): DM was induced with a single intraperitoneal injection of streptozotocin (STZ) (n = 10); group 2 (G2): rats were not exposed to STZ (n = 10). Seven days after DM induction, bilateral fenestration defects were created at the buccal aspect of the first mandibular molar. After the surgeries, the defects of each animal were randomly assigned to two subgroups: non-treated (control) and treated with EMD. The animals were euthanized 21 days later, and the percentage of defect fill (DF), newly formed bone density (BD), and new cementum formation (NCF) were histometrically assessed. The number of osteoclasts was determined by tartrate-resistant acid phosphatase. Weight and blood glucose were also analyzed. Mann-Whitney U test was used for comparison among groups and Wilcoxon test for comparison between the start and end times (weight and blood glucose) and between treatments (NCF and number of osteoclasts). One-way analysis of variance was used to assess DF and BD. Tukey test was used when the analysis of variance test detected significant differences (α = 5%). RESULTS G1 (DM) showed less DF and BD compared with G2. EMD provided an increased DF in both groups and enhanced BD and NCF only in G2. The number of TRAP-positive osteoclasts was significantly higher in EMD-treated sites of G1. CONCLUSIONS DM may produce a significant detrimental effect on BD. EMD may provide greater DF under diabetic or normal conditions; however, it may not significantly increase NCF in animals with DM.

The Impact of Cigarette Smoke Inhalation on the Outcome of Enamel Matrix Derivative Treatment in Rats: Histometric Analysis

BACKGROUND Tobacco use is the most significant risk factor of periodontal disease. Clinical evidence has demonstrated that tobacco may negatively influence the results after surgical and non-surgical periodontal therapy. Enamel matrix derivative (EMD) have been used in periodontal regenerative procedures resulting in improvement of clinical parameters. The effect of EMD in the presence of tobacco compounds is unclear. Thus, the aim of the present study is to evaluate the impact of cigarette smoke inhalation (CSI) on the results of EMD treatment. METHODS Twenty-two Wistar rats were assigned to two groups: Group 1, CSI (n = 11); Group 2, non-exposed (n = 11). Thirty days after initiation of CSI, fenestration defects were created at the buccal aspect of the first mandibular molar. The study followed a split-mouth design. After the surgeries the defects were randomly assigned to two subgroups: non-treated control and treated with EMD. The animals were sacrificed 21 days later and the percentage of defect fill, density of newly formed bone, and new cementum formation were histometrically assessed. The number of osteoclasts was determined by tartrate-resistant acid phosphatase. RESULTS CSI was associated with less bone density compared to the non-exposed group. EMD provided an increased defect fill and new cementum formation in both groups. The number of tartrate-resistant acid phosphatase-positive osteoclasts was significantly higher in the CSI non-treated control group compared to the non-treated control of the non-exposed animals. CONCLUSIONS EMD may provide increased defect fill and cementum formation in the presence or absence of CSI. However, tobacco smoke produced a detrimental effect on bone healing when density of newly formed bone was considered.