Serum biomarker levels in smokers and non-smokers following periodontal therapy. A prospective cohort study.

BACKGROUND: To compare presence and levels of serum cytokines in smokers and non-smokers with periodontitis following periodontal therapy. METHODS: Thirty heavy smokers and 30 non-smokers with stage III or IV periodontitis were included in this prospective cohort study. Clinical data and blood serum were collected at baseline (T0), after step I-III (T1), and after 12 months step IV periodontal therapy (T2). Cytokine IL-1ß, IL-6, IL-8, TNF-α, IL-10, and IP-10 levels were measured using multiplex kit Bio-Plex Human Pro™ Assay. Linear regression models with cluster robust variance estimates to adjust for repeated observations were used to test intra- and intergroup levels for each marker, IL-6 and IL-8 defined as primary outcomes. RESULTS: Clinical outcomes improved in both groups following therapy (p < 0.05). IL-6 levels increased with 75.0% from T0-T2 among smokers (p = 0.004). No significant intra- or intergroup differences were observed for IL-8. Higher levels of TNF-α (44.1%) and IL-10 (50.6%) were detected in smokers compared with non-smokers at T1 (p = 0.007 and p = 0.037, respectively). From T1-T2, differences in mean change over time for levels of TNF-α and IL-10 were observed in smokers compared with non-smokers (p = 0.005 and p = 0.008, respectively). CONCLUSION: Upregulated levels of serum cytokines in smokers indicate a systemic effect of smoking following periodontal therapy. Differences in cytokine levels between smokers and non-smokers demonstrate a smoking induced modulation of specific systemic immunological responses in patients with severe periodontitis.

Periodontal referral patterns in Norway: 2003 versus 2018.

OBJECTIVES: Changes in periodontal referral patterns over time have been reported from the United States and Australia. To date, comparable studies have not been published from Europe. The objectives of the present study were to examine changes in periodontal referral patterns in Norway in 2003 versus 2018 and to compare these with trends observed in the United States and Australia using universal criteria for grading of periodontal severity. MATERIALS AND METHODS: A retrospective analysis of 369 charts from four Norwegian periodontics clinics was completed. Data on year of referral, gender, age, tobacco smoking, periodontal status and missing teeth at initial examination, teeth planned for extraction, and periodontal case type were collected using a survey format; case type I, II, III, and IV representing increasing severity of periodontitis, case type V representing referral for other periodontal conditions (peri-implantitis, refractory periodontitis, etc.). Chi-square, t-tests, and negative binomial regression were used for the statistical analysis. RESULTS: Compared with 2003, the 2018 data showed an increase in mean age at referral (p < 0.05), overall distribution of case type III and V (p = 0.047), and number of missing teeth (p = 0.001). Further, a decrease in prevalence of smokers (p < 0.05), but no change in number of teeth planned for extraction (p = 0.104), were observed. CONCLUSIONS: During a period of 15 years, changes in periodontal referral patterns in Norway are similar to those in the United States and Australia. The adoption of a guideline-based referral practice might be beneficial for both the dental profession and patients.

The efficacy of systemic antibiotics as an adjunct to surgical treatment of peri-implantitis: a systematic review.

BACKGROUND: Microbial biofilm accumulation is the main cause of peri-implantitis. The majority of surgical peri-implantitis treatment protocols suggests adjunctive use of systemic antibiotics to target specific putative bacteria. The aim of this systematic review was to critically evaluate the adjunctive use of systemically administered antibiotics in surgical treatment of peri-implantitis by reviewing previously published systematic reviews and primary studies. METHODS: A systematic literature search was conducted in four electronic databases (MEDLINE, The Cochrane Library, EMBASE, and Web of Science) for randomised controlled trials, cohort studies, case-control studies, and systematic reviews reporting surgical treatment of peri-implantitis with and without adjunctive systemically administered antibiotic therapy. The included systematic reviews and primary studies were qualitatively assessed using AMSTAR and GRADE, respectively. No restrictions were set for date of publication, journal, or language. RESULTS: The literature search identified 681 papers. Only seven systematic reviews and two primary studies met the inclusion criteria. Four out of seven included systematic reviews concluded that no evidence exists for use of systemic antibiotics to improve the clinical outcomes in surgical treatment of peri-implantitis. One review did not estimate the level of evidence, one did not clearly state any beneficial effect, whereas one reported a limited adjunctive effect. Further, the two included primary studies did not show a long-term significant benefit of adjunctive use of systemically administrated antibiotics. However, one study reported a short-term adjunctive effect in patients with modified surface implants. Due to heterogeneity in study design, low number of included primary studies, and grade of bias, no meta-analysis was performed. CONCLUSION: The use of systemically administered antibiotics as an adjunct to surgical interventions of peri-implantitis cannot be justified as a part of a standard treatment protocol. A pervasive problem is the lack of uniform diagnosis criteria for peri-implantitis, deficient information about patient characteristics, absence of high quality long-term randomised controlled trials, and authors' declaration on conflict of interest.

Site-specific treatment outcome in smokers following 12 months of supportive periodontal therapy.

AIM: To evaluate the effect of cigarette smoking on periodontal health at patient, tooth, and site levels following supportive therapy. MATERIALS AND METHODS: Eighty chronic periodontitis patients, 40 smokers and 40 non-smokers, were recruited to a single-arm clinical trial. Periodontal examinations were performed at baseline (T0), 3 months following active periodontal therapy (T1), and 12 months following supportive periodontal therapy (T2). Smoking status was validated measuring serum cotinine levels. Probing depth (PD) ≥ 5 mm with bleeding on probing (BoP) was defined as the primary outcome. Logistic regression analyses adjusted for clustered observations of patients, teeth, and sites and mixed effects models were employed to analyse the data. RESULTS: All clinical parameters improved from T0 to T2 (p < 0.001), whereas PD, bleeding index (BI), and plaque index (PI) increased from T1 to T2 in smokers and non-smokers (p < 0.001). An overall negative effect of smoking was revealed at T2 (OR = 2.78, CI: 1.49, 5.18, p < 0.001), with the most pronounced effect at maxillary single-rooted teeth (OR = 5.08, CI: 2.01, 12.78, p < 0.001). At the patient level, less variation in treatment outcome was detected within smokers (ICC = 0.137) compared with non-smokers (ICC = 0.051). CONCLUSION: Smoking has a negative effect on periodontal health following 12 months of supportive therapy, in particular at maxillary single-rooted teeth.

Surfactant tuning of hydrophilicity of porous degradable copolymer scaffolds promotes cellular proliferation and enhances bone formation.

Poly(l-lactide-co-ɛ-caprolactone) (poly(LLA-co-CL)) has been blended with Tween 80 to tune the material properties and optimize cell-material interactions. Accordingly, the aims of this study were fourfold: to evaluate the effect of low concentrations of Tween 80 on the surface microstructure of 3D poly(LLA-co-CL) porous scaffolds: to determine the effect of different concentrations of Tween 80 on proliferation of bone marrow stromal cells (BMSCs) in vitro under dynamic cell culture at 7 and 21 days; to assess the influence of Tween 80 on the degradation rate of poly(LLA-co-CL) at 7 and 21 days; and in a subcutaneous rat model, to evaluate the effect on bone formation of porous scaffolds modified with 3% Tween 80 at 2 and 8 weeks. Blending 3% (w/w) Tween 80 with poly(LLA-co-CL) improves the surface wettability (p < 0.001). Poly(LLA-co-CL)/3% Tween 80 shows significantly increased cellular proliferation at days 7 and 21 (p < 0.001). Moreover, the presence of Tween 80 facilitates the degradation of poly(LLA-co-CL). Two weeks post-implantation, the poly(LLA-co-CL)/3% Tween 80 scaffolds exhibit significant mRNA expression of Runx2 (p = 0.004). After 8 weeks, poly(LLA-co-CL)/3% Tween 80 scaffolds show significantly increased de novo bone formation, demonstrated by µ-CT (p = 0.0133) and confirmed histologically. It can be concluded that blending 3% (w/w) Tween 80 with poly (LLA-co-CL) improves the hydrophilicity and osteogenic potential of the scaffolds. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2049-2059, 2016.

Site-specific treatment outcome in smokers following non-surgical and surgical periodontal therapy.

AIM: To evaluate the effect of smoking at patient, tooth, and site level following non-surgical and surgical periodontal therapy. MATERIAL AND METHODS: Eighty chronic periodontitis patients, 40 smokers and 40 non-smokers, were recruited to this single-arm clinical trial. Smoking status was validated by measuring serum cotinine levels. Periodontal examinations were performed at baseline (T0) and 3 months following non-surgical and surgical periodontal therapy (T1). At T0 and T1, subgingival plaque samples were collected from the deepest periodontal pocket in each patient and analysed using checkerboard DNA-DNA hybridization. Probing depth (PD) ≥ 5 mm with bleeding on probing (BoP) was defined as the primary outcome. Unadjusted and adjusted logistic regression analyses, corrected for clustered observations within patients and teeth, were conducted comparing smokers with non-smokers. RESULTS: Clinical parameters significantly improved in both groups (p < 0.001). An association was revealed between smoking and PD ≥ 5 mm with BoP (OR= 1.90, CI: 1.14, 3.15, p = 0.013), especially for plaque-positive sites (OR= 4.14, CI: 2.16, 7.96, p < 0.001). A significant reduction of red complex microbiota was observed for non-smokers only (p = 0.010). CONCLUSION: Smokers respond less favourably to non-surgical and surgical periodontal therapy compared with non-smokers, in particular at plaque-positive sites.

Cell seeding density is a critical determinant for copolymer scaffolds-induced bone regeneration.

Constructs intended for bone tissue engineering (TE) are influenced by the initial cell seeding density. Therefore, the objective of this study was to determine the effect of bone marrow stromal stem cells (BMSCs) density loaded onto copolymer scaffolds on bone regeneration. BMSCs were harvested from rat's bone marrow and cultured in media with or without osteogenic supplements. Cells were seeded onto poly(l-lactide-co-ε-caprolactone) [poly(LLA-co-CL)] scaffolds at two different densities: low density (1 × 10(6) cells/scaffold) or high density (2 × 10(6) cells/scaffold) using spinner modified flasks and examined after 1 and 3 weeks. Initial attachment and spread of BMSC onto the scaffolds was recorded by scanning electron microscopy. Cell proliferation was assessed by DNA quantification and cell differentiation by quantitative real-time reverse transcriptase-polymerized chain reaction analysis (qRT-PCR). Five-millimeter rat calvarial defects (24 defects in 12 rats) were implanted with scaffolds seeded with either low or high density expanded with or without osteogenic supplements. Osteogenic supplements significantly increased cell proliferation (p < 0.001). Scaffolds seeded at high cell density exhibited higher mRNA expressions of Runx2 p = 0.001, Col1 p = 0.001, BMP2 p < 0.001, BSP p < 0.001, and OC p = 0.013. More bone was formed in response to high cell seeding density (p = 0.023) and high seeding density with osteogenic medium (p = 0.038). Poly (LLA-co-CL) scaffolds could be appropriate candidates for bone TE. The optimal number of cells to be loaded onto scaffolds is critical for promoting Extracellular matrix synthesis and bone formation. Cell seeding density and osteogenic supplements may have a synergistic effect on the induction of new bone.

Mesenchymal stem cells induce endothelial cell quiescence and promote capillary formation.

INTRODUCTION: Rapid establishment of functional blood vessels is a prerequisite for successful tissue engineering. During vascular development, endothelial cells (ECs) and perivascular cells assemble into a complex regulating proliferation of ECs, vessel diameter and production of extracellular matrix proteins. The aim of this study was to evaluate the ability of mesenchymal stem cells (MSCs) to establish an endothelial-perivascular complex in tissue-engineered constructs comprising ECs and MSCs. METHODS: Primary human ECs and MSCs were seeded onto poly(L-lactide-co-1,5-dioxepan-2-one) (poly(LLA-co-DXO)) scaffolds and grown in dynamic culture before subcutaneous implantation in immunocompromised mice for 1 and 3 weeks. Cellular activity, angiogenic stimulation and vascular assembly in cell/scaffold constructs seeded with ECs or ECs/MSCs in a 5:1 ratio was monitored with real-time RT-PCR, ELISA and immunohistochemical microscopy analysis. RESULTS: A quiescent phenotype of ECs was generated, by adding MSCs to the culture system. Decreased proliferation of ECs, in addition to up-regulation of selected markers for vascular maturation was demonstrated. Baseline expression of VEGFa was higher for MSCs compared with EC (P<0.001), with subsequent up-regulated VEGFa-expression for EC/MSC constructs before (P<0.05) and after implantation (P<0.01). Furthermore, an inflammatory response with CD11b+cells was generated from implantation of human cells. At the end of the 3 week experimental period, a higher vascular density was shown for both cellular constructs compared with empty control scaffolds (P<0.01), with the highest density of capillaries being generated in constructs comprising both ECs and MSCs. CONCLUSIONS: Induction of a quiescent phenotype of ECs associated with vascular maturation can be achieved by co-seeding with MSCs. Hence, MSCs can be appropriate perivascular cells for tissue-engineered constructs.

Endothelial microvascular networks affect gene-expression profiles and osteogenic potential of tissue-engineered constructs.

INTRODUCTION: A major determinant of the potential size of cell/scaffold constructs in tissue engineering is vascularization. The aims of this study were twofold: first to determine the in vitro angiogenic and osteogenic gene-expression profiles of endothelial cells (ECs) and mesenchymal stem cells (MSCs) cocultured in a dynamic 3D environment; and second, to assess differentiation and the potential for osteogenesis after in vivo implantation. METHODS: MSCs and ECs were grown in dynamic culture in poly(L-lactide-co-1,5-dioxepan-2-one) (poly(LLA-co-DXO)) copolymer scaffolds for 1 week, to generate three-dimensional endothelial microvascular networks. The constructs were then implanted in vivo, in a murine model for ectopic bone formation. Expression of selected genes for angiogenesis and osteogenesis was studied after a 1-week culture in vitro. Human cell proliferation was assessed as expression of ki67, whereas α-smooth muscle actin was used to determine the perivascular differentiation of MSCs. Osteogenesis was evaluated in vivo through detection of selected markers, by using real-time RT-PCR, alkaline phosphatase (ALP), Alizarin Red, hematoxylin/eosin (HE), and Masson trichrome staining. RESULTS: The results show that endothelial microvascular networks could be generated in a poly(LLA-co-DXO) scaffold in vitro and sustained after in vivo implantation. The addition of ECs to MSCs influenced both angiogenic and osteogenic gene-expression profiles. Furthermore, human ki67 was upregulated before and after implantation. MSCs could support functional blood vessels as perivascular cells independent of implanted ECs. In addition, the expression of ALP was upregulated in the presence of endothelial microvascular networks. CONCLUSIONS: This study demonstrates that copolymer poly(LLA-co-DXO) scaffolds can be prevascularized with ECs and MSCs. Although a local osteoinductive environment is required to achieve ectopic bone formation, seeding of MSCs with or without ECs increases the osteogenic potential of tissue-engineered constructs.

Alveolar ridge augmentation using implants coated with recombinant human growth/differentiation factor -5 (rhGDF-5). Radiographic observations.

OBJECTIVES: Application of growth factors onto dental implant surfaces is being considered to support local bone formation. Bone morphogenetic protein-2 (BMP-2) and BMP-7 have been shown to support local bone formation, but are also associated with adverse events including seroma formation, extensive bone remodeling, and implant displacement captured in the radiographic evaluation. This report presents mineralized tissue formation and associated adverse events following implantation of recombinant human growth/differentiation factor-5 (rhGDF-5) coated onto a purpose-designed titanium porous-oxide implant surface. MATERIAL AND METHODS: Twelve young adult Labrador dogs were used. Three 10-mm titanium implants/jaw quadrant were placed 5 mm into the alveolar ridge in the posterior mandible following surgical extraction of the premolar teeth and reduction of the alveolar ridge. Six animals received implants coated with rhGDF-5 at 30 or 60 µg/implant in contralateral jaw quadrants. Six animals received implants coated with rhGDF-5 at 120 µg/implant or uncoated implants (sham-surgery control) using the same split-mouth design. The mucoperiosteal flaps were advanced, adapted, and sutured to submerge the implants. Radiographic recordings were made immediately postsurgery (baseline), and at week 4 and 8 (end of study). Two masked examiners performed the analysis using computer enhanced radiographic images. RESULTS: rhGDF-5 coated implants displayed mineralized tissue formation significantly exceeding that of the sham-surgery control in a dose-dependent order. The greatest increase was observed for implants coated with rhGDF-5 at 60 µg and 120 µg amounting to approximately 2.2 mm for both groups at 8 weeks. Importantly, none of the implants showed evidence of peri-implant bone remodeling, implant displacement, or seroma formation. The newly formed mineralized tissues assumed characteristics of the resident bone. CONCLUSIONS: rhGDF-5 coated onto a titanium porous-oxide implant surface exhibits a dose-dependent potential to stimulate local mineralized tissue formation. Application of rhGDF-5 appears safe as it is associated with limited, if any, adverse events.

Er:YAG laser in the treatment of periodontal sites with recurring chronic inflammation: a 12-month randomized, controlled clinical trial.

AIM: The objective of this randomized, controlled clinical trial was to compare the clinical and microbiological effects of pocket debridement using erbium-doped: yttrium, aluminium and garnet (Er:YAG) laser with conventional debridement in maintenance patients. MATERIAL & METHODS: Fifteen patients, all smokers, having at least four teeth with residual probing depth (PD) ≥ 5 mm were recruited. Two pockets in two jaw quadrants were randomly assigned to subgingival debridement using an Er:YAG laser (test) or ultrasonic scaler/curette (control) at 3-month intervals. Relative attachment level (RAL), PD, bleeding on probing and dental plaque were recorded at baseline and at 6 and 12 months. Microbiological subgingival samples were taken at the same time points and analysed using a checkerboard DNA-DNA hybridization technique. RESULTS: A significant decrease in PD took place in both treatments from baseline to 12 months (p < 0.01). In the control, the mean initial PD decreased from 5.4 to 4.0 mm at 12 months. For the test, a similar decrease occurred. No significant between-treatment differences were shown at any time point. The mean RAL showed no overall significant inter- or intra-treatment differences (p > 0.05). No significant between-treatment differences were observed in subgingival microbiological composition or total pathogens. CONCLUSION: The results failed to support that an Er:YAG laser may be superior to conventional debridement in the treatment of smokers with recurring chronic inflammation. This appears to be the first time that repeated Er-YAG laser instrumentation has been compared with mechanical instrumentation of periodontal sites with recurring chronic inflammation over a clinically relevant time period.

Enamel matrix derivative versus bioactive ceramic filler in the treatment of intrabony defects: 12-month results.

BACKGROUND: This study examined the clinical efficacy of enamel matrix derivative (EMD) and bioactive ceramic filler (BCF) in the treatment of intrabony periodontal defects and evaluated factors influencing the treatment outcome. METHODS: Thirteen chronic periodontitis patients, 41 to 74 years of age, who had two proximal intrabony defects in different jaw quadrants with > or =3 mm vertical radiographic bone loss were selected for this study. After initial therapy, the sites in each patient were randomly assigned to EMD or BCF treatment. Clinical attachment level (CAL), probing depth (PD), tooth mobility (TM), gingival recession (GR), bleeding on probing, and dental plaque were recorded at baseline and at 6 and 12 months. At surgery, the intrabony component was characterized by recording the number of bony walls, distance in millimeters from the buccal crest (BC) to the most apical point of the defect, distance from the cemento-enamel junction (CEJ) to the BC, and the mesio-distal width of the defect at the level of the bony crest. RESULTS: BCF treatment resulted in a significant gain in proximal CAL (P = 0.005) and a reduction in proximal PD at 6 months (P <0.001), but there was no further improvement from 6 to 12 months. Paired comparisons by time for the EMD group revealed a significant reduction in proximal PD at 12 months (P = 0.001), whereas the gain in proximal CAL approached significance (P = 0.056). Mean GR increased significantly from baseline to 6 months in both groups (P = 0.001). Regression analysis revealed that within the EMD group, smoking and TM negatively influenced the gain of attachment, whereas within the BCF group, gingival recession increased with age, increasing CEJ to BC distance, and increasing mesial-distal width of the defect. CONCLUSIONS: The gain in proximal attachment after treating intrabony defects by flap surgery with BCF was significant (P = 0.004) and twice that following treatment with EMD (P = 0.056). Patient and site variables affected the clinical outcome differently.

Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-7 (rhBMP-7/rhOP-1): radiographic observations.

AIM: The objective of this study was to radiographically evaluate the potential of a purpose-designed titanium porous-oxide implant surface coated with recombinant human bone morphogenetic protein-7 (rhBMP-7), also known as recombinant human osteogenic protein-1 (rhOP-1), to stimulate alveolar ridge augmentation. MATERIAL AND METHODS: Six young-adult Hound Labrador mongrel dogs were used. Three 10 mm titanium oral implants per jaw quadrant were placed 5 mm into the alveolar ridge in the posterior mandible following surgical extraction of the pre-molar teeth and reduction of the alveolar ridge leaving 5 mm of the implants in a supra-alveolar position. The implants had been coated with rhBMP-7 at 1.5 or 3.0 mg/ml and were randomized to contralateral jaw quadrants using a split-mouth design. The mucoperiosteal flaps were advanced, adapted, and sutured to submerge the implants. Radiographic registrations were made immediately post-surgery (baseline), and at weeks 4 and 8 (end of study). RESULTS: rhBMP-7-coated implants exhibited robust radiographic bone formation. At 8 weeks, bone formation averaged 4.4 and 4.2 mm for implants coated with rhBMP-7 at 1.5 and 3.0 mg/ml, respectively. There were no significant differences between the rhBMP-7 concentrations at any observation interval. A majority of the implant sites showed voids within the newly formed bone at week 4 that generally resolved by week 8. The newly formed bone assumed characteristics of the resident bone. CONCLUSIONS: The titanium porous-oxide implant surface serves as an effective carrier for rhBMP-7 showing a clinically significant potential to stimulate local bone formation.

The critical-size supraalveolar peri-implant defect model: characteristics and use.

OBJECTIVE: Novel implant technologies and reconstructive therapies for alveolar augmentation require pre-clinical evaluation to estimate their biologic potential, efficacy, and safety before clinical application. The objective of this report is to present characteristics and use of the critical-size, supraalveolar, peri-implant defect model. METHODS: Bilateral extraction of the mandibular premolars was performed in 12 Hound Labrador mongrel dogs following horizontal surgical cut-down of the alveolar ridge approximating 6 mm. Each jaw quadrant received three custom-produced TiUnite, phi 4.0 x 10 mm threaded implants placed into osteotomies prepared into the extraction sites of the third and fourth premolars. The implants exhibited a reference notch 5 mm from the implant platform to facilitate surgical placement leaving 5 mm of the implant in a supraalveolar position, and to serve as a reference point in the radiographic, histologic and histometric analysis. The implants were submerged under the mucoperiosteal flaps for primary intention healing. Fluorescent bone markers were administered at weeks 3 and 4 post-surgery, and pre-euthanasia. The animals were euthanized following an 8-week healing interval when block biopsies were collected for analysis. RESULTS: Healing was generally uneventful. The radiographic and histometric evaluations demonstrate the limited osteogenic potential of this defect model. Whereas lingual peri-implant sites exhibited a mean (+/-SE) bone gain of 0.4+/-0.1 mm, resorption of the buccal crestal plate resulted in a mean bone loss of 0.4+/-0.2 mm for an overall osteogenic potential following sham-surgery averaging 0.0+/-0.1 mm. Overall bone density and bone-implant contact in the contiguous resident bone averaged 79.1+/-1.1% and 76.9+/-2.3%, respectively. CONCLUSION: The results suggest that the critical-size, supraalveolar, peri-implant defect model appears a rigorous tool in the evaluation of candidate technologies for alveolar reconstruction and osseointegration of endosseous oral implants. Limited innate osteogenic potential allows critical evaluation of osteogenic, osteoconductive, or osteoinductive technologies in a challenging clinical setting.

Host response to titanium dental implant placement evaluated in a human oral model.

BACKGROUND: Recent reports have questioned if metal sensitivity may arise from exposure to titanium. The objective of this study was to histologically evaluate non-perforated mucosa covering submerged maxillary titanium implants with regard to induced tissue reactions. METHODS: Thirteen patients, 21 to 69 years of age, without previous implants were included. After initial examination, the bone crest areas destined for dental implant placement were exposed, and threaded external hex dental implants were inserted. Prior to wound closure, a full mucosal tissue slice was biopsied from the edge of the mucoperiosteal flap (baseline). The patients were monitored monthly for 6 months. At the abutment connection, biopsies were taken by a 6-mm punch, altogether yielding 26 specimens. Tissue reactions were analyzed by coded histometric analysis at four defined areas at increasing distance from the oral epithelium, including ratios of inflammatory cells (IC)/epithelial cells, IC/fibroblasts, and number of dense particles. RESULTS: The stained sections portrayed gingival tissue with intact oral epithelium and connective tissue with variable accumulation of IC. Experimental biopsies demonstrated mineralized areas and dense particles of different sizes. Analysis of variance revealed a higher IC/fibroblast ratio for level 3 at baseline compared to level 3 at 6 months (P<0.01). Furthermore, a significant decrease in IC/fibroblast ratio was observed between levels 2 and 3 and 2 and 4 at 6 months (P<0.001). The connective tissue level facing the cover screw contained the highest number of dense particles (P<0.01). CONCLUSIONS: Tissue sensitivity reactions to titanium implants were not disclosed. All 6-month biopsies contained dense particles that were most likely metals.

Coronally positioned flap procedures with or without a biodegradable membrane in the treatment of human gingival recession. A 6-year follow-up study.

BACKGROUND: Short-term data have indicated that treatment of gingival recession type defects by coronally positioned flap procedures with or without biodegradable membranes may result in similar treatment outcome. The aim of this study was to compare 12-month and 6-year follow-up results for these two treatment approaches. METHODS: Twenty patients with buccal bilateral Miller Class I or Class II gingival recession defects in cuspids or bicuspids were treated randomly by coronally positioned flap alone (20 sites) or in combination with a biodegradable membrane (20 sites). Clinical measurements at baseline, 6, 12 months and 6 years included apical extent of gingival recession, width of the defect at the cemento-enamel junction (CEJ), width of keratinized tissue, as well as attachment level and probing depth. Eleven patients were available for the 6-year evaluation. RESULTS: At 12 months (20 sites), both treatments resulted in significant gain of root coverage (p<0.001), stable probing depth, and increased attachment level (p<0.001). The 6-year evaluation (11 sites) showed a significant gain of root coverage for the non-membrane group only (p<0.05). No significant between-group differences were detected for any other treatment variable regardless of smoking status (p>0.05). Compared with baseline, the 6-year results showed that seven membrane sites gained root coverage, three were unchanged and one lost root coverage. For the 11 non-membrane sites, eight gained root coverage, and three were unchanged. The five membrane and the 10 non-membrane sites exhibiting complete root coverage at 6 months were reduced to two and one, respectively, at the 6-year evaluation. CONCLUSIONS: The coronally positioned flap procedure offers a simple and reliable treatment alternative as a root coverage procedure in Class I and Class II recession type defects. Placement of a biodegradable membrane underneath the flap does not seem to improve neither the short- nor the long-term results. Long-term outcome stability seems to be critically dependent on a continuous follow-up program with re-instruction in non-traumatic brushing habits.

Human gingival tissue reactions to silk and expanded polytetrafluoroethylene sutures.

BACKGROUND: Wound closure by suturing is a critical and significant event in general as well as in oral surgery. Information regarding tissue reactions to different suture materials appears incomplete and inconsistent, particularly in humans. Thus, the purpose of the present study was to evaluate clinically and histologically tissue reactions to silk and expanded polytetrafluoroethylene (ePTFE) suture materials placed in human oral tissues. METHODS: Twelve patients undergoing periodontal treatment, who had bilateral periodontal defects in the maxillary premolar and molar region scheduled for resective surgery, were included. In each patient, one single interrupted ePTFE suture (CV-5) and one single interrupted silk suture (4-0) were inserted in gingival tissues in contralateral jaw quadrants 10 days prior to scheduled surgery and a second set of sutures was inserted at 7 days prior to surgery. After placement, the length of the suture embedded in the tissue as well as the slack of the suture loop were measured and tabulated. The measurements were repeated on the day of surgery. At this time biopsy specimens, including the suture loop and surrounding tissue, were harvested and processed for histologic analysis. The inflammatory response was evaluated by measuring the thickness of the perisutural epithelium and the diameter of the connective tissue infiltrate, by estimating the proportion of inflammatory cells to epithelial cells, and by recording the presence or absence of bacterial plaque along the suture track. RESULTS: At 7 days, silk sutures showed a significantly higher degree of slack of the suture loop than did ePTFE sutures (P= 0.02), while the difference was not significant at 10 days (P= 0.21). The mean change of "tissue bite" was greater for silk compared to ePTFE at 7 as well as at 10 days. However, none of the differences were statistically significant (P= 0.43). The thickness of the perisutural epithelium increased significantly from 7 to 10 days for both suture materials, while the difference in proportion of inflammatory cells to epithelial cells was not significant (P= 0.43). An overall significantly greater diameter of connective tissue infiltrate was present around the silk sutures. Bacterial plaque was detected in 10 of 11 silk and four of 11 ePTFE suture channels at 7 days, and eight of 10 and four of 11 suture channels at 10 days. CONCLUSIONS: The results revealed that placement of sutures in gingival tissues elicits an inflammatory reaction and that the magnitude of this reaction may vary with the suture material used. Braided silk sutures apparently cause a more extensive inflammatory tissue reaction in an environment characterized by moisture and infectious potential.

Tissue reactions to sutures in the presence and absence of anti-infective therapy.

BACKGROUND: In the oral cavity, sutures are placed within tissues of high vascularity in a moist environment with infectious potential. The objective of this study was to evaluate tissue reactions at silk and expanded polytetrafluoroethylene (ePTFE) sutures in the presence and absence of anti-infective therapy (AT). METHODS: Thirty-six sutures were placed within the mandibular keratinized gingiva in six Beagle dogs. Each animal received one braided silk (4-0) and one ePTFE (CV-5) suture in contra-lateral jaw quadrants at 14, 7, and 3 days prior to biopsy. Three animals received daily AT including topical 2% chlorhexidine solution and a systemic broad-spectrum antibiotic. Biopsy specimens allowed histometric analysis of tissue reactions along the central part of the suture loop including the area of perisutural epithelium, ratio inflammatory cells (ICs)/epithelial cells and IC/fibroblasts, and presence/absence of bacterial plaque in the suture track. RESULTS: A perisutural epithelial sheath was forming within 3 days. The cross-sectional area of the epithelium increased with time for both suture materials (p=0.003) but was particularly pronounced for the silk sutures in the absence of AT. Clusters of IC were present in the perisutural connective tissue and epithelium. Over time, a more prominent increase in IC/fibroblasts was evident for the silk sutures in the absence of AT. The pooled material revealed a significantly higher IC/fibroblast ratio for silk compared with ePTFE sutures (p=0.017). Bacterial plaque influx was detected in 6/9 silk and 0/9 ePTFE suture channels in the presence, and 6/6 and 3/6 suture channels, respectively, in the absence of AT. CONCLUSIONS: AT may reduce biofilm formation and inflammation along the suture track. Braided silk, however, elicits more severe tissue reactions than ePTFE regardless of infection control.

Altered healing following mucogingival surgery in a patient with Crohn's disease: a literature review and case report.

BACKGROUND: Crohn's disease is a chronic inflammatory bowel disease characterized by uncertainty in etiology and pathogenesis occasionally with manifestations in oral mucous membranes. This report reviews the literature on Crohn's disease and presents a patient with Crohn's disease on continuous anti-inflammatory and immunosuppressive medication who showed adverse healing response following surgical treatment of gingival recession type defects. METHODS: A 28-year-old male in generally good health apart from his bowel disease requested treatment of multiple maxillary gingival recessions due to esthetic concerns and root sensitivity. Following oral hygiene instruction, 3 coronally advanced flap procedures were performed in the maxillary anterior region to cover the defects. In 2 of the surgical areas, the exposed root surfaces were treated by ethylenediaminetetraacetic acid (EDTA) in combination with enamel matrix derivative (EMD) before coronally positioning the buccal flap. Postoperatively, chlorhexidine gluconate was used for oral hygiene control. RESULTS: The first surgical procedure, performed as a coronally advanced flap, showed delayed and altered healing. Two weeks postoperatively, the flapped tissue remained intensely red and swollen. In the following 2 surgical sites where EDTA and EMD were applied the healing was uneventful. Differences in immediate tissue response, however, did not influence the 3-month treatment outcome with respect to root coverage. CONCLUSIONS: Patients with Crohn's disease on recommended systemic medications may show a delayed and altered wound healing indicating that periodontal surgery must be closely monitored. Treatment planning should take into account the potential wound healing promoting effects of enamel matrix derivative as well as adverse healing effects of chlorhexidine gluconate administration.