Comparison of Skeletal and Dental Reference Planes with the Hamulus-Incisive-Papilla Plane: A Pilot Study on 3D Reconstructed Tomographies of the Skull.

PURPOSE: The aim of this study was to investigate the hamulus-incisive-papilla (HIP) plane as an alternative for transferring the three-dimensional position of a patient's maxilla to an articulator. MATERIALS AND METHODS: Camper, Frankfurt horizontal, occlusal, and HIP planes were evaluated in 21 patients' computed tomography scans and compared to one another. RESULTS: Analysis of variance showed significant differences between all planes, with the HIP plane being closest to the occlusal plane (HIP-OP: 0.6 ± 4.0 degrees). Frankfurt and Camper planes, being more peripheral, showed higher geometric asymmetries. CONCLUSION: The HIP plane, when used for articulator mounting, results in a closer and more technically reliable patient relationship in a clinical and laboratory context.

Effects of Shock Waves on Expression of IL-6, IL-8, MCP-1, and TNF-α Expression by Human Periodontal Ligament Fibroblasts: An In Vitro Study.

BACKGROUND: Extracorporeal shock wave therapy (ESWT) can modulate cell behavior through mechanical information transduction. Human periodontal ligament fibroblasts (hPDLF) are sensible to mechanical stimulus and can express pro-inflammatory molecules in response. The aim of this study was to evaluate the impacts of shock waves on interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor-alpha (TNF-α) expression by hPDLF. MATERIAL/METHODS: After being treated by shock waves with different parameters (100-500 times, 0.05-0.19 mJ/mm(2)), cell viability was tested using CCK-8. IL-6, IL-8, MCP-1, and TNF-α gene expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and IL-6 and IL-8 protein was measured by enzyme-linked immunosorbent assay (ELISA) at different time points. RESULTS: Shock waves with the parameters used in this study had no significant effects on the viability of hPDLF. A statistical inhibition of IL-6, IL-8, MCP-1, and TNF-α expression during the first few hours was observed (P<0.05). Expression of IL-8 was significantly elevated in the group receiving the most pulses of shock wave (500 times) after 4 h (P<0.05). At 8 h and 24 h, all treated groups demonstrated significantly enhanced IL-6 expression (P<0.05). TNF-α expression in the groups receiving more shock pulses (300, 500 times) or the highest energy shock treatment (0.19 mJ/mm(2)) was statistically decreased (P<0.05) at 24 h. CONCLUSIONS: Under the condition of this study, a shock wave with energy density no higher than 0.19 mJ/mm(2) and pulses no more than 500 times elicited no negative effects on cell viability of hPDLF. After a uniform initial inhibition impact on expression of inflammatory mediators, a shock wave could cause dose-related up-regulation of IL-6 and IL-8 and down-regulation of TNF-α.

Effect of double conical abutment screw on implant preload.

OBJECTIVE: This study compared the loosening torque of experimental double conical abutment screws to that of conventional conical abutment screws and flat-head screws in implants with internal connections before and after mechanical loading. MATERIAL AND METHODS: Eighty implant-screw-abutment assemblies were divided into four groups: flat-head screw (Xive S), conical screw (Straumann), conical screw (Nobel Biocare), and double conical screw (RTB). Abutments were tightened to a torque of 30 Ncm. After 10 min, they were retightened and loosening torque was measured. The same abutments were then retightened with new screws to a torque of 30 Ncm and, again, retightened after 10 min. They were then mechanically loaded for 3 000 000 cycles, and loosening torque was again measured. Data were collected, and an exploratory analysis was performed. RESULTS: Comparisons before mechanical cycling showed significant differences between groups. After mechanical cycling, only the comparisons of Straumann and Nobel Biocare showed no significant differences. Considering the same group before and after mechanical cycling, all comparisons showed significant differences. CONCLUSION: The shape of the abutment screw head significantly influenced loosening torque: Double conical-head screws showed significantly higher loosening torque values than conical-head screws. Conical-head screws showed higher loosening torque values than conventional flat-head screws before and after loading.

Effect of extracorporeal shockwave therapy (ESWT) on pulpal blood flow after orthodontic treatment: a randomized clinical trial.

OBJECTIVES: The effect of non-invasive extracorporeal shockwaves on pulpal blood flow in orthodontic patients who have undergone active treatment was investigated. MATERIALS AND METHODS: Seventy-two adult patients were enrolled in the clinical trial and allocated by block randomization to a treatment or a placebo group at a 1:1 ratio. The patients were required to be otherwise healthy. Blinding was performed for the subjects and the outcome assessor. The region of interest was the mandibular incisors and canines, which were vital, unrestored, and had experienced no trauma. The active treatment group received a single shockwave treatment with 1000 impulses at 0.19-0.23 mJ/mm(2) while the placebo group was treated with a deactivated shockwave applicator but acoustic sham. Pulpal blood flow was evaluated four times over a period of 6 months starting from the day of bracket removal, using a laser Doppler device. RESULTS: Thirty patients were evaluated in each group. Orthodontic patients who have undergone active treatment tend to have high levels of pulpal blood flow which decrease over a period of 6 months. Pulpal blood flow did not differ significantly over 6 months between the placebo and treatment group. Shockwave treatment was associated with no significant effect in respect of tooth type, age, sex, or mean blood pressure, and had no unintended pernicious effects. CONCLUSIONS: Extracorporeal shockwaves had no statistically significant effect on pulpal blood flow. Multiple applications of ESWT in a pathological setup may be needed in future studies to demonstrate significant differences. CLINICAL RELEVANCE: The absence of any adverse effects justifies further principal investigations of the use of shockwave treatment in the oral cavity.

Effect of different enamel matrix derivative proteins on behavior and differentiation of endothelial cells.

OBJECTIVES: Enamel matrix derivative (EMD) is an effective biomaterial for periodontal tissue regeneration and might stimulate angiogenesis. In order to clarify mechanisms underlying its biological activity, we separated two EMD fractions with different molecular weight protein components and investigated their effects on human umbilical vein endothelial cells (HUVECs) in vitro. METHODS: Fraction Low-Molecular Weight (LMW) included proteins with a molecular weight (M.W.)<8kDa. Fraction LMW-depleted included proteins with M.W.>8kDa and lower than approximately 55kDa. The effect of EMD fractions on proliferation/viability, apoptosis, migration and expression of angiopoetin-2 (ang-2), von Willebrand factor (vWF), E-selectin, intracellular adhesion molecules 1 (ICAM-1), vascular endothelial growth factor (VEGF) receptors Flt-1 and KDR was investigated. RESULTS: The proliferation/viability of HUVECs was inhibited by both LMW and LMW-depleted at concentrations 100µg/ml, whereas EMD slightly increased cell proliferation/viability. The expression of all investigated proteins was up-regulated by EMD. However, differences in the effect of EMD fractions on the protein expression were observed. The effect of LMW-depleted on the expression of ICAM-1 and E-selectin was markedly higher compared to LMW. In contrast, the expression of vWF and VEGF receptors Flt-1 and KDR was primarily affected LMW than by LMW depleted. The expression of ang-2 was not influenced by LMW and LMW-depleted. HUVECs migration was stimulated more strongly by LMW than by EMD and LMW-depleted. CONCLUSION: Our in vitro study shows that the proteins composing EMD have different and specific biological activities and consequently have the ability to cover different aspects of EMD's biological and clinical effects.

Impact of extracorporeal shockwave therapy on tooth mobility in adult orthodontic patients: a randomized single-center placebo-controlled clinical trial.

AIM: This RCT investigated the effect of non-invasive extracorporeal shockwaves on tooth mobility in orthodontic patients after active treatment. MATERIALS AND METHODS: Seventy-two adult patients were included in the study. Immediately after active orthodontic treatment, patients were assigned to a treatment or a placebo group based on block randomization. The orthodontic patients were required to be otherwise healthy. The region of interest was the anterior portion of the mandible. The treatment group received a single shockwave treatment with 1000 impulses while the placebo group was treated with an acoustic sham. Tooth mobility was evaluated over a period of 6 months using a Periotest and manual testing. Pocket probing depths, bleeding on probing and the irregularity index were also assessed. RESULTS: Tooth mobility reduced significantly over 6 months in both groups, but shockwaves achieved significantly more rapid reduction on manual testing. Probing depth was significantly reduced while the irregularity index remained stable. Bleeding on probing was significantly reduced in the treatment group. No anti-inflammatory effect could be derived due to possible initial group differences. CONCLUSIONS: The mobility of teeth aligned by orthodontic treatment reduces over time. Shockwave treatment appeared to reduce tooth mobility more rapidly.

Behavior of osteoblasts on TI surface with two different coating designed for orthodontic devices.

In the present study we coated Ti surfaces with polytetrafluorethylene (PTFE) and titanium nitride (TiN) and investigated in vitro the behavior of osteoblasts on these surfaces. MG-63 osteoblasts were cultured on titanium discs with different surface treatment: uncoated Ti6Al4V, TiN-coated, PTFE-coated. Cell viability/proliferation was detected by MTT assay. Gene-expression levels of alkaline phosphatase (ALP), osteocalcin (OC), type I collagen, receptor activator of nuclear factor-kappa-B ligand (RANKL), and osteoprotegerin (OPG) were determined by qPCR. Cell behavior on different surfaces was observed by time-lapse microscopy. Cells grown on PTFE-coated Ti surface exhibited delayed surface attachment and decreased proliferation after 48 h. However, after 168 h of culture cells grown on PTFE-coated surface exhibited higher viability/proliferation, higher expression levels of ALP and OC, and higher OPG/RANKL ratio compared to uncoated surface. No effect of TiN-coating on any investigated parameter was found. Our results shows that PTFE coating exhibits no toxic effect on MG-63 cells and slightly stimulates expression of several genes associated with osteogenesis. We propose that PTFE coating could be considered as a possible choice for a surface treatment of temporary skeletal anchorage devices in orthodontics.

Impact of extracorporeal shock-wave therapy on the stability of temporary anchorage devices in adults: a single-center, randomized, placebo-controlled clinical trial.

INTRODUCTION: In this randomized, placebo-controlled clinical trial, we investigated the effect of noninvasive extracorporeal shock waves on the stability of temporary anchorage devices (TADs) under orthodontic loading. METHODS: Thirty adult orthodontic patients of the Bernhard Gottlieb University Clinic in Vienna, Austria, were enrolled in this clinical trial and allocated by block randomization (size, 4) in a 1:1 ratio to either the treatment or the placebo group. Randomization was performed with software, and the allocations were concealed in sealed envelopes. Eligibility criteria included healthy adult patients with mesially directed orthodontic movement of the mandibular second molar into the extraction site of the mandibular first molar. The fixed orthodontic devices included active superelastic coil springs (200 cN) and TADs in the mandibular alveolar bone. Blinding was performed for the subjects and the outcome assessor. The treatment group received 1 shock-wave application with 1000 impulses at 0.19 to 0.23 mJ per square millimeter in the region of the TADs. The placebo group was treated with a deactivated shock-wave applicator and acoustic sham. The TADs positions were evaluated at placement and after 4 months. The reliability and precision of the impression process of the TADs were evaluated in an in-vitro model. RESULTS: Thirteen participants finished the investigation successfully in the treatment group but only 12 finished in the placebo group because 1 TAD loosened. The difference of the total TAD displacement for the 4-month time period between the placebo and treatment groups was 0.17 ± 0.95 mm (95% CI: -0.96, 0.62). No statistically significant difference between the 2 groups was found when sex was evaluated. Primary stability of the TADs as measured by placement torque, amount of tooth movement, and age of the patients did not influence displacement of the TADs. The reliability and precision of TAD impressions were confirmed. No unintended pernicious effects occurred after shock-wave treatment during the study period. CONCLUSIONS: A single application of extracorporeal shock-wave treatment did not improve the stability of the TADs during orthodontic loading. Sufficient interradicular space should be provided to minimize the risk of periodontal and dental root defects. REGISTRATION: This trial was registered at https://clinicaltrials.gov. PROTOCOL: The protocol was published before trial commencement, NCT01695928. FUNDING: No funding or conflict of interest to be declared.

The impact of education on the perception of facial profile aesthetics and treatment need.

BACKGROUND: The purpose of this study was to evaluate the influence of education on the perception of various male and female Caucasian profiles with respect to attractiveness and treatment need. METHODS: Four hundred questionnaires were distributed among six groups of raters (nonacademic laymen, academic laymen, preclinical students, clinical students, orthodontists, and maxillofacial surgeons). Male and female profile images were altered digitally in the sagittal and vertical dimensions resulting in nine different male and female profiles. The raters had to assess the images according to attractiveness and treatment needs. RESULTS: Three hundred four questionnaires were completed in this study. Age and gender of the rater had no significant influence on the perception of profile attractiveness. The different groups of raters perceived the Class I normodivergent profiles as most attractive. Significant differences in the perception of attractiveness were seen between laymen, orthodontists, and maxillofacial surgeons. The orthodontists and maxillofacial surgeons reported treatment needs the most. The orthodontists were most sensitive in discerning profiles. CONCLUSION: Attractive male and female profiles are recognizable by any rater. Education seemed to have a significant influence on facial profile perception and recommendation for treatment need of unattractive profiles. Professionals should be aware of their judgment discrepancy to laymen. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Influence of different conditioning methods on immediate and delayed dentin sealing.

STATEMENT OF PROBLEM: Data are needed to evaluate the effect of various conditioning methods on immediate and delayed dentin sealing. PURPOSE: The purpose of this study was to test bond strength and surface configuration of immediate and delayed dentin sealing surfaces after applying different surface conditioning methods. MATERIAL AND METHODS: A total of 96 premolars were allocated to the immediate and delayed groups. The groups differed in the timing of dentin sealing. The immediate-group specimens were sealed with a self-etching adhesive immediately after preparation. The delayed-group specimens were sealed before the final ceramic restoration bonding. Provisional restorations were cemented on immediate-group and delayed-group specimens for 1 week. Four conditioning methods were used: polishing with fluoride-free pumice paste, airborne-particle abrasion with silicoated aluminum oxide, glycin, or calcium carbonate. After 24-hour storage, the shear bond strength was tested. The fractured specimens were optically inspected with a stereomicroscope. An optical 3-dimensional surface analysis was performed for quantitative and qualitative evaluation. A 2-way ANOVA with post hoc Tukey honestly significant difference tests for significant effects was performed to investigate effects of the 2 factors, sealing and conditioning, and their interaction (α=.05). RESULTS: Two-way ANOVA found significant differences between the sealing and conditioning groups. The immediate group had significantly lower bond strengths than the delayed group. In all groups, surface polishing produced the highest bond strengths, and airborne-particle abrasion with calcium carbonate produced the lowest. Fracture analysis found more failures in the adhesive layers in the immediate groups and a prevalence of mixed failures in the delayed groups. The surface analysis found significant abrasion and roughness when airborne-particle abrasion with silicoated aluminum oxide was used for immediate and delayed dentin sealing surfaces. CONCLUSIONS: Polishing and airborne-particle abrasion with silicoated aluminum oxide or glycin are efficient methods in conditioning immediate and delayed dentin sealing surfaces. Airborne-particle abrasion with silicoated aluminum oxide leaves significant surface alterations on both types of surfaces.

Effect of nicotine and porphyromonas gingivalis lipopolysaccharide on endothelial cells in vitro.

Smoking is considered a significant risk factor for both periodontal disease and cardiovascular disease (CVD). Endothelial cells play an important role in the progression of both diseases. In the present study, we investigated in vitro the impact of nicotine on functional properties of human umbilical vein endothelial cells (HUVECs) stimulated with lipopolysaccharide (LPS) of periodontal pathogen Porphyromonas gingivalis. HUVECs were stimulated with different concentrations of nicotine (10 µM-10 mM) and/or P. gingivalis LPS. Expression levels of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, monocyte chemoattractant protein 1, and interleukin-8 were measured on both gene and protein levels. Cell proliferation/viability, apoptosis, and migration were also investigated. Nicotine at a concentration of 10 mM significantly decreased P. gingivalis LPS-induced expression of all investigated proteins after 4 h stimulation, while lower nicotine concentrations had no significant effect on protein expression with or without P. gingivalis LPS. Proliferation/viability of HUVECs was also significantly inhibited by 10-mM nicotine but not by lower concentrations. Migration of HUVECs was significantly decreased by nicotine at concentrations of 1-10 mM. Nicotine at a concentration similar to that observed in the serum of smokers had no significant effect on the functional properties of HUVECs. However, high concentrations of nicotine, similar to that observed in the oral cavity of smokers, inhibited the inflammatory response of HUVECs. This effect of nicotine might be associated with decreased gingival bleeding indices in smoking periodontitis patients.

Impact of extracorporeal shock wave therapy (ESWT) on orthodontic tooth movement-a randomized clinical trial.

OBJECTIVES: This randomized clinical trial investigated the effect of extracorporeal shock waves on the amount of orthodontic tooth movement and periodontal parameters. MATERIAL AND METHODS: Twenty-six adult orthodontic patients participated in this clinical trial; all of them receiving lower second molar mesially directed movement. The fixed orthodontic device included superelastic coil springs (200 cN) and miniscrews as temporary anchorage device. The active treatment group received a single shock wave treatment with 1,000 impulses in the region of tooth movement. The placebo group was treated with deactivated shock wave applicator with an acoustic sham. The study period lasted 4 months with a monthly data exploration. RESULTS: No statistically significant difference in posterior-anterior tooth movement between the treatment and placebo group was seen during observation period. Gender had no significant influence on tooth movement in either group. No significant difference occurred in mesio-distal tipping and rotation, but a significant difference (p = 0.035) in bucco-lingual tipping of the molars was found. Periodontal status of the patients (sulcus probing depth, gingival index) did not significantly differ in both groups. The plaque index showed a significant difference (p = 0.003). CONCLUSIONS: Single application of extracorporeal shock wave treatment was associated neither with a statistically significant acceleration of tooth movement nor with an altered periodontal status in vivo. CLINICAL RELEVANCE: Shock waves showed no harmful effects in the investigated area. Their clinical use for lithotripsy during orthodontic therapy might be permitted.

Color stability of different composite resin materials.

STATEMENT OF PROBLEM: Data are needed to better predict the color stability of current composite resin materials. PURPOSE: The purpose of this study was to evaluate the impact of different storage solutions on the color stability of different composite resin materials. MATERIAL AND METHODS: Different restorative and adhesive composite resin specimens (dual-polymerizing self-adhesive resin cement, autopolymerizing resin-based composite resin, dual-polymerizing resin-based composite resin, nanohybrid composite resin, and microhybrid composite resin) were fabricated and stored in red wine, black tea, chlorhexidine, sodium fluoride, tea tree oil, or distilled water for 4 weeks at 37°C. Color parameters were measured with a colorimeter before and after storage. Total color differences and specific coordinate differences were expressed as ΔE, ΔL, Δa, and Δb. A 2-way and 1-way analysis of variance (ANOVA) with Bonferroni adjustment for multiple comparisons were applied for statistical calculations (α=.05). RESULTS: Red wine caused the most severe discoloration (ΔE >10), followed by black tea with perceptible (ΔE >2.6) to clinically unacceptable discoloration (ΔE >5.5). Colored mouth rinses discolored the materials to a lesser extent with clinically acceptable values. Dual-polymerizing resin adhesives showed a higher amount of discoloration. CONCLUSIONS: Current restorative and adhesive composite resin materials discolor over time under the influence of different storage solutions. The composition related to the polymerizing mode seemed to be a causative factor.

Rebonding performance of different ceramic brackets conditioned with a new silane coupling agent.

The objective of this study was to investigate the rebonding effect of a new silane coupling agent on various ceramic brackets bonded to ceramic specimen. Different ceramic brackets (Fascination 2, Clarity SL, and In-OvationC) were assigned to three groups: rebonding with new silane coupling agent, rebonding with conventional silane coupling agent, or regular bonding as control (n = 16). Bracket adhesion was calculated with a shear test in a universal testing machine. The bracket-composite-ceramic interface was evaluated using the adhesive remnant index score. One-way analysis of variance was applied for inferential statistics. Rebonding with the new silane coupling agent resulted in high shear bond strengths (SBSs; mean values: 37.44-41.24 MPa) and ceramic specimen fractures. Rebonding with the conventional silane coupling agent resulted in significantly (P < 0.001) lower clinically adequate SBS (mean values: 20.20-29.92 MPa) with the least ceramic specimen fractures. Regularly bonded ceramic brackets resulted in clinically adequate to high SBS (mean values: 17.06-41.56 MPa) depending on their bracket base design. Rebonded ceramic brackets showed sufficient SBS to ceramic specimen surfaces. However, increased bracket adhesion was associated with a risk of ceramic specimen surface damage. Therefore, ceramic brackets rebonded with the new silane coupling should be debonded cautiously using alternative debonding methods.

Influence of surface conditioning on ceramic microstructure and bracket adhesion.

The objective of this study was to investigate the influence of different conditioning procedures on various ceramic microstructures and bracket adhesion. Ceramic specimens (feldspathic, leucite, leucite-free, and fluorapatite) were mechanically conditioned (n = 20 per ceramic type) with conventional hydrofluoric acid (5 per cent HF; 60/30 seconds), buffered hydrofluoric acid (9.6 per cent BHF; 60/30 seconds), or sandblasting (Al(2)O(3)/SiO(2) particles). Silane coupling agents were added for chemical conditioning before bracket bonding. Bracket adhesion was calculated with a shear test in a universal testing machine. The bracket-composite-ceramic interface was further evaluated using the adhesive remnant index (ARI). One specimen of each ceramic/conditioning combination was subjected to qualitative electron microscopy investigation. One-way analysis of variance followed by Tukey's honestly significant difference test were applied for inferential statistics. Conditioning with conventional 5 per cent HF or sandblasting resulted in significantly (P < 0.001) higher bond strengths (mean values: 34.11 and 32.86 MPa, respectively) than with 9.6 per cent BHF (mean value: 12.49 MPa). Etching time or sandblasting particles had no statistical (P > 0.001) influence on bond strength. Higher ARI scores were found in the conventional 5 per cent HF and sandblasted groups, when compared with the 9.6 per cent BHF group. Microscopic examination of the conditioned ceramic surfaces showed that leucite and leucite-free ceramics differed most with respect to their surface roughness, though without an influence on shear bond strength (SBS; P < 0.001). Bracket adhesion was mostly influenced by the conditioning procedure itself. Sandblasted ceramic surfaces showed sufficient conditioning and bracket adhesion; however, the increased bracket adhesion was associated with a risk of ceramic surface damage.