Five-year outcomes of a randomized clinical trial comparing bone-level implants with either submerged or transmucosal healing.

AIM: To evaluate the long-term hard and soft tissue peri-implant tissue stability of bone-level implants using a different implant placement protocol (submerged versus transmucosal). MATERIALS AND METHODS: This study was partly a subset analysis of a multicentre study where in 40 patients, a single bone-level implant with platform switching and a conical implant-abutment interface was placed either submerged or transmucosal in non-molar sites. Changes in the peri-implant tissues between implant placement and 5 years were assessed clinically and radiologically. Patient-related outcomes were also recorded. RESULTS: Thirty patients completed the 5-year follow-up. Implant survival rate was 100%. The mean radiographic changes in crestal bone levels between baseline and 5 years were 0.59 (0.92) mm and 0.78 (1.03) mm for the submerged and the transmucosal groups, respectively. No statistical significant differences were found between the groups for any of the investigated variables. Peri-implantitis, defined as changes in the level of crestal bone of ≥2 mm together with bleeding on probing, was only diagnosed in one patient. Patients in both groups were highly satisfied with the treatment received. CONCLUSIONS: Bone-level implants with submerged or transmucosal healing protocols demonstrated similar outcomes after 5 years. Both protocols yielded optimal clinical and radiographic results when bone-level implants were placed in non-molar positions for single tooth replacement.

Optimization of buffer solutions to analyze inflammatory cytokines in gingival crevicular fluid by multiplex flow cytometry.

OBJECTIVE: the aim of this study was to test two buffer solutions in order to attain a reliable and reproducible analysis of inflammatory cytokines (IL-1ß, IL-6, TNF-α, OPG, OPN and OC), in gingival crevicular fluid (GCF) by flow cytometry. MATERIAL AND METHODS: GCF samples from healthy volunteers were collected with perio-paper strips and diluted either in phosphate buffered saline (PBS) or Tris-HCl buffer, with and without protease inhibitors (PI). Cytokine immunoassays were carried out by flow cytometry (Luminex Xmap 200) generating standard curves. RESULTS: standards curves generated with the use of phosphate-buffered saline (PBS) demonstrated best adjustment for cytokines IL-1ß, IL-6 and TNF- α levels, when using Tris-HCl (p<0.05). CONCLUSIONS: The use of PBS buffer with the addition of PI provided reliable measurements of inflammatory biomarkers in GCF samples of healthy volunteers.

Calcitonin gingival crevicular fluid levels and pain discomfort during early orthodontic tooth movement in young patients.

OBJECTIVES: To investigate the previously unreported presence of calcitonin (CT) levels in gingival crevicular fluid (GCF), its variations during initial orthodontic tooth movement in both tension and compression sites, and its possible association with the experienced dental pain. DESIGN: Fifteen children (mean age: 12.6 years) requiring orthodontic closure of the upper midline diastema were included. We collected GCF from the compression and tension sites of the upper right central incisor (experimental) and first bicuspid (control), before and after (1h, 24h, 7d, 15d) beginning of treatment. Calcitonin levels were determined by Western blot. Pain intensity was assessed using a visual analogue scale. RESULTS: Calcitonin levels were higher in the compression site versus the control site at 7d (p=0.014). Intragroup comparisons showed an increment of CT between 1h and 7d (680.81±1672.60pg/30s, p=0.010) in the compression site. No significant changes were found in the tension and control sites. Calcitonin levels and pain intensity were negatively associated during the period from 24h to 15d (r=-0.54, p=0.05). CONCLUSIONS: CT levels in the GCF significantly increased in the compression site after the short term after application of orthodontic forces. These changes were negatively associated with the perceived patient's dental pain during the period from 24h to 15d.

Biochemical markers of bone metabolism in gingival crevicular fluid during early orthodontic tooth movement.

OBJECTIVE: To evaluate the expression of an activator of nuclear factor-kappa (RANK), osteoprotegerin (OPG), osteopontin (OPN), and transforming growth factor ß1 (TGF-ß1) in gingival crevicular fluid (GCF) of teeth subjected to orthodontic forces. MATERIALS AND METHODS: A randomized, pilot clinical trial including 10 healthy volunteers was conducted using a split-mouth design. Orthodontic elastic separators were placed between the second premolar and first molar, with the contralateral quadrant serving as a control. The GCF samples were collected from the tension and compression sites at baseline, 24 hours, and 7 days after the placement of separators. The GCF sample volumes were measured using a Periotron 8000, and total protein concentrations were determined. Levels of RANK, OPG, OPN, and TGF-ß1 were also analyzed using a multiplex enzyme-linked immunosorbent assay. RESULTS: The control sites remained unchanged throughout the study. In contrast, the concentration of OPG significantly decreased at the compression site by 24 hours, and the amount and concentration of RANK differed significantly between the control, compression, and tension sites after 7 days. A significant increase in absolute TGF-ß1 levels was also detected at the compression site versus the control and tension sites after 7 days. CONCLUSION: Bone metabolism is affected by application of force to the teeth by elastic separators. Both increased expression of bone resorptive mediators (eg, RANK and TGF-ß1) and decreased expression of a bone-forming mediator (eg, OPG) on the compression side were detected.

Parotid secretory protein is expressed and inducible in human gingival keratinocytes.

BACKGROUND: Parotid secretory protein (PSP) is a major salivary protein that is thought to possess both antibacterial and anti-inflammatory activity. A major question is whether PSP expression can be regulated by humoral factors and bacteria. Periodontitis is an inflammatory lesion initiated by interaction between gingival keratinocytes and periodontopathogenic microorganisms such as the Gram-negative anaerobe Porphyromonas gingivalis. Cytokines and sex hormones have been implicated in the progression of various forms of periodontal diseases. MATERIALS AND METHODS: We investigated the expression of PSP and its regulation in primary cultures of human gingival keratinocytes (HGK). HGK at the third or fourth passage were exposed to heat-killed P. gingivalis, tumor necrosis factor-alpha (TNF-alpha) and 17beta-estradiol. The PSP mRNA levels were examined by real-time polymerase chain reaction (PCR). The protein expression of PSP was confirmed by immunofluorescence. RESULTS: Heat-killed P. gingivalis, TNF-alpha and 17beta-estradiol all resulted in increased HGK levels of mRNA for PSP as determined by real-time PCR analysis. Immunofluorescence demonstrated increased PSP localized within the cytoplasm of HGK following exposure to killed P. gingivalis. CONCLUSION: The present study has demonstrated for the first time that PSP is expressed in keratinocytes and that it can be up-regulated by bacteria and humoral factors. Thus PSP may have a role in the innate defense system at the gingival epithelial surface.

Efficacy of a 0.15% benzydamine hydrochloride and 0.05% cetylpyridinium chloride mouth rinse on 4-day de novo plaque formation.

OBJECTIVE: To evaluate the effect of a mouth-rinse formulation combining benzydamine hydrochloride and cetylpyridinium chloride (BNZ+CPC) in preventing de novo plaque formation, in comparison with CPC and placebo mouth rinses. PATIENTS AND METHODS: This was a controlled, observer-blind, cross-over study. In this model of plaque re-growth, subjects received a session of oral prophylaxis and were directed to withdraw oral hygiene measures for the next 4 days, using only the mouth rinse assigned. The outcome parameters were the plaque index (PlI) and gingival index (GI). In addition, microbiological evaluation of the subgingival microflora, by means of culture, was performed, as well as patient-based variables. Data analysis was carried out using anova for Latin-square design. RESULTS: The analysis of variance showed a significant statistical difference between the BNZ+CPC association and placebo (p<0.0001). No differences between CPC and placebo were detected considering multiple comparisons between treatments. The 90% confidence interval of the differences between BNZ+CPC and CPC showed no equivalence between treatments, being the PlI lower in the BNZ+CPC group. No significant difference between groups in GI was observed. Mean anaerobic colony-forming units (CFU) demonstrated a significant increase between visits in all groups (p<0.001) and differences among groups were not significant. Subjects treated with BNZ+CPC frequently reported "tingling mouth" and "numbness mouth". CONCLUSION: Within the limitations of the study model, the BNZ+CPC combination showed a statistically significant plaque-inhibitory capacity, as compared with the placebo mouth rinse, and an additive effect as compared with CPC. No relevant clinical or microbiological adverse effects were detected.