Molecular Analysis of Peri-implant Soft Tissue Response to Different Abutment Materials in Humans. A Pilot Study.

PURPOSE: To evaluate the response of human peri-implant soft tissue (PIST) on different healing abutment materials 24 hours after positioning, by assessing the expression of genes related to the early connective tissue wound healing response. MATERIALS AND METHODS: Experimental abutments of 4 different materials (A): grade 4 titanium, (B) grade 5 titanium, (C) zirconia and (D) PEEK, were mounted on installed implants in 5 patients, four different abutments each. Before implant placement, a gingival biopsy (control-CT) was obtained using a 2 mm diameter punch (T0). After 24 hours (T24), PIST biopsies were collected using a specifically designed custom-made cutting device. Real-time PCR was performed to analyze the expression of the following genes: COL-I, COL-III, MMP-1, TIMP-1,TGF-b1, FN, ITGA4, ITGA5, ITGB1, RAC-1, COL-IV, aSMA, IL-6 and CXCL-1. RESULTS: Gene expression analysis showed some differences between CT and abutment of different materials, although no significant differences were detected comparing the experimental groups. COL-I was significantly down-regulated in groups A and C compared to CT. MMP-1 and TIMP-1 increased in all the experimental groups, although at a lower extent in group A. FN, RAC-1, COL-IV and aSMA were down-regulated, especially in group A, in which CXCL-1 and IL-6 showed the lowest expression. CONCLUSIONS: The results of grade 4 titanium and zirconia abutments seem to be promising, since a lower expression of genes related with inflammation, myofibroblasts activation and ECM remodeling was observed when compared with grade 5 titanium and PEEK, without triggering a pro-fibrotic response in the early phases of PIST repair.

Treatment of Residual Periodontal Pockets Using a Hyaluronic Acid-Based Gel: A 12 Month Multicenter Randomized Triple-Blinded Clinical Trial.

The aim of the present study was to evaluate the adjunctive effect of hyaluronic acid (HA) gel in the treatment of residual periodontal pockets over a 12-month period. Periodontal patients presenting at least one residual periodontal pocket 5-9 mm of depth in the anterior area were recruited from six university-based centers. Each patient was randomly assigned to subgingival instrumentation (SI) with the local adjunctive use of HA for test treatment or adjunctive use of local placebo for control treatment at baseline and after 3 months. Clinical parameters ( )probing depth (PD), bleeding on probing (BoP), plaque index (PI), recession (REC), clinical attachment level (CAL)) and microbiological samples for the investigation of the total bacterial count (TBC) and presence of specific bacterial species (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum) were taken at baseline and every 3 months, until study termination. PD was determined as the primary outcome variable. From a total of 144 enrolled, 126 participants (53 males, 73 females) completed the entire protocol. Both treatments resulted in statistically significant clinical and microbiological improvements compared to baseline. Although the local application of HA showed a tendency for better results, there was a lack of statistically significant differences between the groups.

Histologic Analysis of Clinically Healthy Human Gingiva in Patients with Altered Passive Eruption.

The purpose of this study was to histologically examine the clinically healthy gingiva of patients with altered passive eruption (APE). Five patients with type 1 APE were enrolled. They underwent scaling and polishing and received oral hygiene instructions. After 6 months of supervised plaque control and uninterrupted gingival clinical health (Gingival Index (GI) = 0 and no Bleeding on Probing (BoP)), upper anterior teeth were surgically treated. During the surgical procedure, the excised gingival margin was collected to be histologically examined. In four out of five patients, signs of inflammation including spongiosis and neutrophil exocytosis could be found in the epithelium of the gingival sulcus. Ulceration with exposure of the lamina propria and inflammatory granulation tissue were evident in the most severe cases. Normal density and orientation of collagen fibers could be seen within the superficial and the deep portions of connective tissue, with an increase in size and number of the deep collagen fibers and a reduced laxity of the superficial ones. In conclusion, the clinically healthy gingiva of APE patients showed features compatible with persistent inflammation, possibly due to recurrent traumatisms caused by an incisally placed gingival margin.

Experimental gingivitis in patients with and without altered passive eruption.

BACKGROUND: Individuals with altered passive eruption (APE) are assumed to be more susceptible to periodontal diseases. To date, this hypothesis has not been sufficiently supported by scientific evidence. The aim of this study, using an experimental gingivitis model, was to examine the development and resolution of gingival inflammation in patients with APE when compared to patients with normal gingival anatomy. METHODS: A localized experimental gingivitis was induced in 9 patients with APE (test group) and 9 patients without APE (control group) in the maxillary right quadrant. After 21 days, patients were instructed to resume proper home oral hygiene procedures. At baseline (day 0) and at days 7, 14, 21, 28, 35, and 42, plaque index (PlI), gingival index (GI), and gingival crevicular fluid volume (GCF) were evaluated for teeth 6 (canine), 7 (lateral incisor) and 8 (central incisor) of test and control groups. RESULTS: During the experimental gingivitis phase (days 0 to 21), the rate of change in gingival inflammation (GI) was dramatically different between the APE test group and the control group. On day 21, at the time of maximum plaque accumulation, the GI of the APE test group was a 109% greater than the GI of the test group (P ≤ 0.001) despite similar plaque levels (P = 0.436). During the resolution of inflammation phase (days 22 to 42), the APE test group continued to exhibit statistically higher GI scores than the control group (P = 0.029). CONCLUSION: In the presence of similar amounts of plaque deposits and plaque accumulation rates, APE patients exhibited differences in the development and resolution of plaque-induced gingival inflammation when compared to controls.

Adjunctive use of an ethyl lauroyl arginate-(LAE-)-containing mouthwash in the nonsurgical therapy of periodontitis: a randomized clinical trial.

BACKGROUND: This randomized clinical trial evaluated the clinical and microbiological effects of 0.147% ethyl lauroyl arginate (LAE)-containing mouthwash compared to 0.12% chlorhexidine (CHX) mouthwash in the treatment of periodontitis. METHODS: Subjects were randomized to use 0.147% LAE and 0.12% CHX mouthwash after professional mechanical plaque removal (PMPR) twice daily 1 hour after brushing for 4 weeks. Periodontal pocket depth (PPD), bleeding on probing (FMBS) and dental plaque (FMPS) were measured at baseline, 4 weeks and 3 months. Microbiological samples were taken at baseline, at 4 weeks and 3 months after plaque recording and prior to PPD and BoP measurements. RESULTS: Forty subjects were randomized to treatment. Both therapies resulted in reduced FMPS, FMBS and residual pockets at 4 weeks and 3 months. The differences were not statistically significant. There were no treatment-related adverse events. Total bacterial count and the specific pathogens were reduced at 4 weeks and 3 months by both mouthwashes with no statistical differences between them at neither period of time. CONCLUSIONS: A mouthwash containing 0.147% LAE could be an alternative to the use of 0.12% CHX in the non-surgical therapy of periodontitis considering the similar clinical effects, more stable microbiological improvement and absence of adverse effects.

Aspartate aminotransferase activity in peri-implant mucositis: experimental peri-implant mucositis model of 14 days.

BACKGROUND: Experimental peri-implant mucositis has been studied from various prospective in a duration of 21 days. Given the higher sensitivity of peri-implant mucosa the aim of the present study was to evaluate if a duration of 14 days would be sufficient to establish a state of measurable inflammation. METHODS: Twenty patients of age 57±11-year-old contributed with 20 clinically healthy implants and teeth. They were instructed to use an individual stent in the selected elements prior to performing oral hygiene for 14 days. For each element plaque index (PlI), probing depth (PD), bleeding on probing (Bops) were reported at 0 days and 14 days of plaque accumulation. Aspartate aminotransferase activity was measure at both time points from the crevicular fluid. RESULTS: Both implant and teeth developed similar increased response of inflammation at 14 days compared to day 0: BoPs of 4.2±1.8 (P=0.06) and BoPs of 3.1±2.2 (P=0.048) for implant and tooth, respectively. Implant presented deeper pocket depth at both time periods but less plaque accumulation. AST activity did not increased significantly, but it was significantly higher at implant level. CONCLUSIONS: Forteen days of plaque accumulation seemed to be sufficient for the establishment of peri-implant mucositis. However, AST did not resulted as a proper indicator of initial peri-implant inflammation.

Implant Patient Compliance Varies by Periodontal Treatment History.

BACKGROUND: This retrospective study aims to assess compliance to supportive periodontal therapy (SPT) among patients treated with dental implants with different periodontitis histories and the possible influence of their compliance on peri-implant marginal bone level. METHODS: Dental records of 106 patients treated with at least one dental implant were reviewed. A single operator who did not provide care to the patients recorded the following during the first year of implant function (first year of follow-up), during the first 5 years of follow-up, and during the entire follow-up duration: 1) number of recalls; 2) compliance, calculated from registered attendance; 3) periodontal disease history; 4) peri-implant radiographic bone level from most recent examination; and 5) clinical parameters including probing depth and bleeding on probing. Clinical and radiographic parameters were assessed at site level and analyzed for possible associations among them and with demographic parameters. RESULTS: Collected data were based on 156 implants with an average of 6.5 ± 3.4 years (range: 1 to 13 years) in function. Patients with periodontitis history demonstrated greater compliance than patients without periodontitis history during the two longer follow-up times. Over time, the majority of patients demonstrated partial compliance (71% to 80% of patients). Peri-implant bone level averaged 0.9 ± 1.1 mm, without significant association with compliance level; however, positive periodontitis history and more years in function were significantly associated with greater peri-implant bone loss. CONCLUSIONS: Patients with implants partially comply with scheduled SPT, regardless of periodontitis history. Patients who had received periodontal treatment demonstrated better compliance than those without prior periodontal therapy experiences.

Chitosan brush for professional removal of plaque in mild peri-implantitis.

BACKGROUND: The aim of the study was to evaluate the effectiveness of a chitosan brush on the treatment of mild peri-implantitis. METHODS: Fifteen patients diagnosed with mild peri-implantitis contributing with single implant were treated with a chitosan brush. Modified plaque index (mPll), Modified Bleeding Index (mBoP) and probing depth (PPD) were recorded at baseline, 2, 4, 12 and 24 weeks. Chitosan brush was used at 12 weeks if diagnosis was still present. Periapical radiographs were taken at the beginning of the study and 6 months after to control the stability of bone level. RESULTS: None of the patients reported discomfort or side effects during treatment. Bone level was maintained stable during the entire study. Plaque index remained almost 0 at every control visit. PPD and mBoP were significantly reduced at 2 weeks and when compared to baseline. At 24 weeks 73% of patients presented no further bleeding on probing with stable bone level. CONCLUSIONS: Chitosan brush could be a reliable instrument for the professionally administered plaque removal and resolution of clinical signs of initial stages of peri-implant inflammation.

Adjunctive efficacy of probiotics in the treatment of experimental peri-implant mucositis with mechanical and photodynamic therapy: a randomized, cross-over clinical trial.

AIM: To evaluate the adjunctive clinical efficacy of probiotics in the treatment of peri-implant mucositis (p-iM) with professionally administered plaque removal (PAPR) and photodynamic therapy (PDT). MATERIALS AND METHODS: Following p-iM induction, patients underwent PAPR + PDT and were randomly assigned to receive the professional and home-based administration of probiotics (Lactobacillus plantarum and Lactobacillus brevis) (test treatment) or placebo preparation (control treatment) according to a cross-over design. Clinical parameters were assessed at six sites for each implant before as well as at 2 and 6 weeks after professional treatment administration. RESULTS: Twenty patients contributing one dental implant each were included. Immediately before treatment and at 6 weeks, the median number of sites with bleeding on probing (BoP+) sites per implant unit was 4 (3-6) and 2 (0-2) (p < 0.001), respectively, for test treatment, and 3.5 (2-4) and 2 (0-3) (p = 0.03), respectively, for control treatment. No significant difference in clinical outcomes was observed between treatment groups. CONCLUSION: The combination of PAPR and PDT either alone or associated with probiotics determined a significant reduction in the number of BoP+ sites at 2 and 6 weeks around implants with p-iM. The adjunctive use of probiotics did not significantly enhance the clinical outcomes of PAPR + PDT.

Clinical evaluation of the regenerative potential of EMD and NanoHA in periodontal infrabony defects: a 2-year follow-up.

INTRODUCTION: The aim of this retrospective study was to compare the clinical efficacy of four different surgical techniques in promoting periodontal regeneration in patients with infrabony defects: open flap debridement, application of enamel matrix derivatives (EMD), nanohydroxyapatite (nanoHA) application, and combined nanoHA and EMD application. Probing attachment level (PAL), pocket depth (PD), and position of gingival margin at completion of therapy (REC) were measured. MATERIALS AND METHODS: Data were collected from 64 healthy patients (34 women and 30 men, mean age 37,7 years). Clinical indices were measured by a calibrated examiner at baseline and at 12, 18, and 24 months. The values obtained for each treatment were compared using nonparametric tests. RESULTS: All treatments resulted in a tendency toward PD reduction over time, with improvements in REC and PAL. The differences in PD, REC, and PAL values at baseline compared with values after 12, 18, and 24 months were statistically significant for all treatments. Statistically significant differences in PAL and PD were detected between nanoHA and nanoHA + EMD at 12, 18, and 24 months. CONCLUSION: In this study, EMD and nanoHA used together in patients with infrabony periodontal lesions had better clinical efficacy than nanoHA alone, EMD alone, or open flap debridement.

Analysis of human alveolar osteoblast behavior on a nano-hydroxyapatite substrate: an in vitro study.

BACKGROUND: Nano-hydroxyapatite (nHA) is a potential ideal biomaterial for bone regeneration. However, studies have yet to characterize the behavior of human osteoblasts derived from alveolar bone on nHA. Thus, the aim of the present study was to evaluate the influence of nHA on the adhesion, proliferation and differentiation of these alveolar bone-derived cells. METHODS: Primary human alveolar osteoblasts were collected from the alveolar ridge of a male periodontal patient during osseous resective surgery and grown on culture plates coated with either polylysine or polylysine with nano-hydroxyapatite (POL/nHA) composite. The cells were grown and observed for 14 days, and then assessed for potential modifications to osteoblasts homeostasis as evaluated by quantitative reverse transcriptase-polymerase chain reaction (real time RT-PCR), scanning electron microscopy and atomic force microscopy. RESULTS: Real time PCR revealed a significant increase in the expression of the selected markers of osteoblast differentiation (bone morphogenetic protein (BMP)-2,-5,-7, ALP, COLL-1A2, OC, ON) in cells grown on the POL/nHA substrate. In addition, as compared with the POL surface, cells grown on the POL/nHA substrate demonstrated better osteoconductive properties, as demonstrated by the increase in adhesion and spreading, likely as a result of the increased surface roughness of the composite. CONCLUSIONS: The increased expression of BMPs and osteoinductive biomarkers suggest that nano-hydroxyapatite may stimulate the proliferation and differentiation of local alveolar osteoblasts and thus encourage bone regeneration at sites of alveolar bone regeneration.

Peri-implant mucositis treatments in humans: a systematic review.

AIM: Peri-implant mucositis affects 39.4-80% of patients restored with dental implants. If left untreated it evolves in peri-implantitis. Thus far no predictable successful treatment has been reported for peri-implantitis, resulting in implant failure. Proper diagnosis and treatment of peri-implant mucositis is of crucial importance. This study aims to provide a comprehensive review of the available data regarding the effectiveness of peri-implant mucositis treatments in humans, parameters used for the diagnosis and treatment effect evaluation. MATERIALS AND METHODS: A literature search for RCT and observational studies on peri-implant mucositis treatments in humans was conducted on Pubmed up to January 2012. CONSORT/STROBE and PRISMA checklists guided the evaluation of studies found and the writing of this review, respectively. RESULTS: Only 5 studies fulfilled the selection criteria. Few possibly effective treatments were studied. Diagnostic parameters reported were clinical only, while treatment effect evaluation was based on clinical and microbiological changes, except for one study reporting biochemical analysis. An evident heterogeneity characterized the follow-up intervals and methods used for reporting parameters changes. CONCLUSIONS: Neither of studied treatments gave complete resolution of peri-implant mucositis. Different treatment strategies need to be studied. Authors suggest guidelines for a protocol of parameters used for determining the sample size, diagnosis and treatment effect, as well as follow-up periods, in order to permit evidence and comparison of different treatments effectiveness.