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.

Periodontitis in obese adults with and without metabolic syndrome: a cross-sectional study.

BACKGROUND: Epidemiological studies support an association between obesity, metabolic syndrome (MetS), and periodontitis. Still, understanding of the effects of low-grade inflammation in obese subjects on periodontitis and influence of MetS remains incomplete. The aims of this cross-sectional study were to explore the association between obesity related variables and periodontitis, and assess if MetS is a risk indicator for periodontitis in a sample of obese adults. METHODS: The study sample comprised 52 adults with a body mass index (BMI) of ≥ 30 kg/m2 referred for obesity therapy at the Obesity Centre at Haukeland University Hospital (HUH), Bergen, Norway. The subjects had prior to enrolment completed a 5-month lifestyle intervention course as part of a 2-year managing program. According to the revised National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) classification of MetS, 38 subjects were recruited to the MetS group and 14 subjects to the non-MetS group. Medical data including peripheral blood samples were obtained from records at HUH at the time of enrolment. Probing depth, clinical attachment level, tooth mobility, furcation involvement, bleeding on probing (BoP) were recorded and intraoral bitewings evaluated at a full-mouth periodontal examination. Associations between risk variables for obesity/MetS and periodontitis were explored using linear and logistic regression models. RESULTS: In the present sample 79% of the subjects were diagnosed with periodontitis. The prevalence of stage III/IV periodontitis was 42.9% in the non-MetS group vs. 36.8% in the MetS group (p = 0.200). In the non-MetS group 29.8% of the sites displayed BoP vs. 23.5% in the MetS group (p = 0.048). For stage III/IV periodontitis, the effect of age appeared to be significant for obesity related variables and MetS (p = 0.006, p = 0.002, respectively). None of the other analyses showed significant association with the outcome variables. CONCLUSION: In the present sample of obese subjects, periodontitis occurred independently of MetS. Reaching a certain BMI level, suggested association between MetS and periodontitis might be non-significant due to the dominating impact of obesity related variables undermining the effect of other systemic factors. TRIAL REGISTRATION: The principal clinical trial, entitled "Obesity and Oral Diseases", was prospectively registered in ClinicalTrials.gov with registration NCT04602572 (20.10.2020).

Non-surgical treatment of peri-implantitis with and without erythritol air-polishing a 12-month randomized controlled trial.

BACKGROUND: A variety of interventions have been explored in the non-surgical management of peri-implantitis. In spite of extensive testing of various study protocols, effective treatments largely remain unavailable. The objective of the present 12-month single-centre, examiner-masked, randomized controlled clinical trial was to explore whether a low-abrasive erythritol air-polishing system produces added clinical benefit when used adjunctive to conventional non-surgical management of peri-implantitis and to record any associated patient-centered outcomes. METHODS: Forty-three patients with mild to severe peri-implantitis including at least one implant either received ultrasonic/curette subgingival instrumentation and erythritol air-polishing (test) or ultrasonic/curette instrumentation only (control) at baseline and at 3, 6, 9, and 12 months. Probing depth (PD), bleeding on probing (BoP), dental plaque, suppuration (SUP), crestal bone level (CBL), and peri-implant crevicular fluid (PCF) were recorded at baseline, 6 and 12 months. Visual Analogue Scale (VAS) scores were collected immediately following subgingival interventions at all time-points. RESULTS: A reduction in PD was observed from baseline to 6 months for the test (p = 0.006) and control (p < 0.001) and from baseline to 12 months for the control (p < 0.001). No intergroup differences were observed for primary outcome variables PD or CBL over time (p > 0.05). At 6 months, a intergroup difference in PCF was observed in favor of the test (p = 0.042). Moreover, a reduction in SUP from baseline to 6 and 12 months was observed in the test (p = 0.019). Overall, patients in the control group experienced less pain/discomfort compared with the test (p < 0.05), females reporting more pain/discomfort than males (p = 0.005). CONCLUSIONS: This study confirms that conventional non-surgical management of peri-implantitis produces limited clinical improvement. It is shown that an erythritol air-polishing system may not produce added clinical benefits when used adjunctive to conventional non-surgical management. In other words, neither approach effectively resolved peri-implantitis. Moreover, the erythritol air-polishing system produced added pain/discomfort particularly in female patients. TRIAL REGISTRATION: The clinical trial was prospectively registered in ClinicalTrials.gov with registration NCT04152668 (05/11/2019).

Dental implant surface morphology, chemical composition, and topography following double wavelength (2780/940 nm) laser irradiation. An in vitro study.

OBJECTIVE: The aim of this in vitro study was to evaluate morphology alterations, chemical composition, and topography of moderately rough dental implants following double-wavelength laser irradiation. MATERIAL AND METHODS: Commercial-grade titanium dental implants representing different surface characteristics (Osseospeed [OS], TiUnite [TiU], and Roxolid SLActive [RS]) were used. Laser irradiation was performed using a computer-controlled robotic device with calibrated energy/power settings and deionized water spray. Micro-, nano-morphology surface alterations, chemical composition, and surface topography (Sa , Sds , Sdr ) in the test group (laser plus water), control group A (water only), and control group B (no treatment) were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and white light laser profilometer (Interferometry). RESULTS: SEM-evaluation revealed minor between-group differences in micro- and nano-morphology within each implant system. Significant overall differences in surface element content were observed between the test and control group B for all implant systems (p < .05). For the test compared with control group B, statistically significantly higher oxygen content was detected for OS and RS (p < .05), a corresponding significant difference was detected for carbon for TiU (p < .05). For RS, a significantly lower content of titanium and zirconium was detected within the test group (p < .05). A significant difference in topography between test and control group B was observed for OS (Sa : p = .039 and Sdr : p = .041) with the highest roughness value for control group B. CONCLUSIONS: Altered chemical composition and surface topography were observed for all implant surfaces compared with untreated control following double wavelength laser irradiation. A clinical evaluation of the impact of the altered surface composition following double wavelength laser irradiation on the ability to reosseointegrate appears warranted.

Reversible, non-plaque-induced marginal bone loss around an osseointegrated implant: A case report.

This case report documents a non-plaque-induced marginal bone loss around an osseointegrated implant. The loss of osseointegration, most likely caused by overload and/or suboptimal distribution of occlusal loading, may be reversed when the loading is reduced by optimally transmitting stress forces to the implant-to-bone interface and surrounding bone.

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.

Complication following frenectomy: A case report.

When performing a frenectomy in patients with an increased risk of exposing bone dehiscence, it is essential that the distance between the incisions is not too wide and that they are mainly made in the movable mucosa to secure optimal wound closure.

A 12-month randomized controlled trial evaluating erythritol air-polishing versus curette/ultrasonic debridement of mandibular furcations in supportive periodontal therapy.

BACKGROUND: Due to complex morphology and limited access, the cleaning of the furcation area is extremely challenging. Therefore, novel therapeutic approaches need to be tested to potentially overcome debridement limitations. The aim of the present prospective 12-month study was to compare clinical and microbiological effects following erythritol air-polishing versus conventional mechanical debridement of furcation defects in a cohort of periodontal maintenance patients. METHODS: Twenty patients with grade II mandibular molar furcation defects volunteered to enroll in this single-centre, examiner masked, randomized controlled trial. In a split-mouth study design, two furcation sites in each patient were randomly assigned to either receive subgingival debridement using erythritol air-polishing (test) or conventional ultrasonic/curette debridement (control) at baseline, and at 3, 6, 9 and 12 months. Probing depth, clinical attachment level and bleeding on probing were recorded at 3-month intervals. Subgingival microbiological samples obtained at baseline, 6 and 12 months were analyzed using checkerboard DNA-DNA hybridization. Discomfort from treatment was scored at 12 months using a visual analogue scale. The differences between treatments, and time-points, were tested using multilevel analysis (mixed effect models and robust variance estimates). RESULTS: A significant reduction in probing depth took place following both treatments (p < 0.001). Control sites experienced a significant mean gain in clinical attachment level of 0.5 mm (± 0.2) (p = 0.004), whereas a non-significant gain of 0.4 mm (± 0.3) was observed at test sites (p = 0.119). At 6 months, a significant between-treatment difference of 0.8 mm (± 0.4) was observed in favor of the control (p = 0.032). No significant between-treatment differences were observed in microbial load or composition. Notably, at 12 months patients experienced significantly less discomfort following air-polishing compared with control (p = 0.001). CONCLUSIONS: The 12-month observations indicate that erythritol air-polishing and conventional mechanical debridement both support clinical improvements. A significant between-treatment difference in clinical attachment level was, however, detected in favour of control debridement at 6 months. In terms of patient comfort, erythritol air-polishing is superior. TRIAL REGISTRATION: The clinical trial was retrospectively registered in ClinicalTrial.gov with registration NCT04493398 (07/28/2020).

Dental implant surface temperatures following double wavelength (2780/940 nm) laser irradiation in vitro.

OBJECTIVE: To estimate the implant surface temperature at titanium dental implants during calibrated irradiation using double wavelength laser. MATERIAL AND METHODS: A double wavelength laser, 2780 nm Er,Cr:YSGG and 940 nm diode, was calibrated and used to irradiate pristine titanium dental implants, OsseoSpeed, TiUnite and Roxolid SLActive, representing different surface modifications. Initial calibration (21 implants; 7 implants/group) intended to identify optimal wavelength/specific output power/energy that not critically increased the temperature or altered the micro-texture of the implant surface. Subsequent experimental study (30 implants; 10 implants/group) evaluated implant surface temperature changes over 190 s. Irradiation using a computerized robotic setup. RESULTS: Based on the initial calibration, the following output powers/energies were employed: Er,Cr:YSGG laser 18.4 mJ/pulse (7.3 J/cm2 )-36.2 mJ/pulse (14.4 J/cm2 ) depending on implant surface; diode laser 3.3 W (1321.0 W/cm2 ). During double wavelength irradiation, implant surface temperatures dropped over the first 20 s from baseline 37°C to mean temperatures ranging between 25.7 and 26.3°C. Differences in mean temperatures between OsseoSpeed and TiUnite implants were statistically significant (p < 0.001). After the initial 20 s, mean temperatures continued to decrease for all implant surfaces. The decrease was significantly greater for TiUnite and Roxolid SLActive compared with OsseoSpeed implants (p < 0.001). CONCLUSION: Calibrated double wavelength laser irradiation did not critically influence the implant surface temperature. During laser irradiation the temperature decreased rapidly to steady-state levels, close to the water/air-spray temperature.

Antimicrobial Effects of Three Different Treatment Modalities on Dental Implant Surfaces.

Resolution of peri-implant inflammation and re-osseointegration of peri-implantitis affected dental implants seem to be dependent on bacterial decontamination. The aims of the study were to evaluate the antimicrobial effects of 3 different instrumentations on a micro-textured dental implant surface contaminated with an avirulent or a virulent Porphyromonas gingivalis strain and to determine alterations to the implant surface following instrumentation. Forty-five dental implants (Straumann SLA) were allocated to 3 treatment groups: Er:YAG laser, chitosan brush, and titanium curette (10 implants each) and a positive (10 implants) and a negative (5 implants) control. Each treatment group and the positive control were split into subgroups of 5 implants subsequently contaminated with either the avirulent or virulent P. gingivalis strain. The antimicrobial effect of instrumentation was evaluated using checkerboard DNA-DNA hybridization. Implant surface alterations were determined using a light interferometer. Instrumentation significantly reduced the number of attached P. gingivalis ( P < .001) with no significant differences among groups ( P = .310). A significant overall higher median score was found for virulent compared with avirulent P. gingivalis strains ( P = .007); the Er:YAG laser uniquely effective removing both bacterial strains. The titanium curette significantly altered the implant surface micro-texture. Neither the Er:YAG laser nor the chitosan brush significantly altered the implant surface. The 3 instrumentations appear to have a similar potential to remove P. gingivalis. The titanium curette significantly altered the microstructure of the implant surface.

A Copolymer Scaffold Functionalized with Nanodiamond Particles Enhances Osteogenic Metabolic Activity and Bone Regeneration.

Functionalizing polymer scaffolds with nanodiamond particles (nDPs) has pronounced effect on the surface properties, such as improved wettability, an increased active area and binding sites for cellular attachment and adhesion, and increased ability to immobilize biomolecules by physical adsorption. This study aims to evaluate the effect of poly(l-lactide-co-ε-caprolactone) (poly(LLA-co-CL)) scaffolds, functionalized with nDPs, on bone regeneration in a rat calvarial critical size defect. Poly(LLA-co-CL) scaffolds functionalized with nDPs are also compared with pristine scaffolds with reference to albumin adsorption and seeding efficiency of bone marrow stromal cells (BMSCs). Compared with pristine scaffolds, the experimental scaffolds exhibit a reduction in albumin adsorption and a significant increase in the seeding efficiency of BMSCs (p = 0.027). In the calvarial defects implanted with BMSC-seeded poly(LLA-co-CL)/nDPs scaffolds, live imaging at 12 weeks discloses a significant increase in osteogenic metabolic activity (p = 0.016). Microcomputed tomography, confirmed by histological data, reveals a substantial increase in bone volume (p = 0.021). The results show that compared with conventional poly(LLA-co-CL) scaffolds those functionalized with nDPs promote osteogenic metabolic activity and mineralization capacity. It is concluded that poly(LLA-co-CL) composite matrices functionalized with nDPs enhance osteoconductivity and therefore warrant further study as potential scaffolding material for bone tissue engineering.

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.

Patient knowledge and expectations prior to receiving implant-supported restorations.

PURPOSE: Implant dentistry has revolutionized the treatment of partially and completely edentulous patients. The aims of this study were to explore what made patients choose implant treatment and their prior knowledge and expectations of this treatment option. MATERIALS AND METHODS: A study population of 117 subjects was selected from 248 referred possible candidates for implant therapy. The subjects answered a questionnaire regarding implant dentistry prior to professional consultation at two hospital/university-based centers and one private implant center. RESULTS: In most cases, the choice of treatment was motivated by expectations of improved chewing/function (46.0%), appearance (19.5%), or both (18.6%). Improved chewing/function and improved appearance were rated "very important" by 96.5% and 86.1% of patients, respectively. Surprisingly, 57.4% reported that the cost of treatment did not play a role in their decision. Only 6.0% claimed to have much prior knowledge about the treatment and 33.6% had a realistic perception about the length of anticipated service. Patients first received implant-related information primarily (62.9%) from dentists, and 75.2% thought their dentist gave the most useful information. Significant positive associations were found between knowledge about the treatment, the need for periodic professional oral health maintenance, and expected treatment time. CONCLUSION: Patients seek implant therapy primarily to improve chewing function and esthetics, whereas cost seems to be less important. Prior to treatment, many patients lack precise information on the importance of necessary implant-related hygiene measures and implant longevity. The general dentist is the primary source of information.

Biodegradable polymer scaffolds loaded with low-dose BMP-2 stimulate periodontal ligament cell differentiation.

Poly(L-lactide)-co-(epsilon-caprolactone) [poly(LLA-co-CL)] and poly(L-lactide)-co-(1,5-dioxepan-2-one) [poly(LLA-co-DXO)] are being considered candidate scaffolds for bone tissue engineering. We evaluated the bioactive potential of poly(LLA-co-CL) and poly(LLA-co-DXO) scaffolds loaded with low-dose bone morphogenetic protein-2 (BMP-2). Periodontal ligament (PDL) cells were cultured onto the various scaffolds loaded with 1 µg BMP-2 or without BMP-2 (control). Cell viability, attachment, and proliferation were determined using a methylthiazol tetrazolium (MTT) colorimetric assay at day 1, 3, and 7. Scanning electron microscopy was used to analyze cell morphology at day 7. Cell differentiation was evaluated assaying alkaline phosphatase (ALP) activity at day 7, 14, and 21. Real-time PCR was used to evaluate the mRNA expression of periostin, ALP, type I collagen, bone sialoprotein and BMP-2. A commercially available enzyme-linked immunosorbent assay was used to assess BMP-2 production. Surface analysis disclosed excellent cell attachment, spread, and penetration into the porous scaffolds. The MTT assay indicated that scaffolds loaded with low concentration of BMP-2 did not influence the viability of cells. Cells grown on the modified scaffolds expressed higher levels of osteogenic markers than the nonmodified scaffolds (p<0.05). Poly(LLA-co-CL) and poly(LLA-co-DXO) scaffolds loaded with low-dose BMP-2 exhibited a significant effect stimulating PDL differentiation suggesting a continued evaluation in relevant in vivo models.

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.