Analysis of the Pulpal Blood Flow Microdynamics during Prosthetic Tooth Preparation Using Diamond Burs with Different Degrees of Wear.

Pulpal modifications taking place during prosthetic tooth preparation using worn-out burs may represent a risk for the vitality of the dental pulp. The aim of this in vivo study was to evaluate whether the wear of diamond burs has an influence on the vascular microdynamics at the level of the dental pulp, during vertical preparation for zirconia crowns. The study was performed with a split-mouth design and included 32 vital permanent monoradicular teeth (20 maxillary and 12 mandibular), from six subjects, aged between 20 and 50 years. The teeth were randomly assigned to two study groups of 16 teeth each. For prosthetic preparation, new burs were used in the first group, and burs at their 5th use were used in the second group. Four consecutive determinations of the pulpal blood flow by Laser Doppler flowmetry (LDF-laser Doppler MoorLab instrument VMS-LDF2, Moor Instruments Ltd., Axminster, UK) were taken for each tooth included in the study: before the preparation (control values), immediately, at 24 h, and at 7 days after the prosthetic preparation. A four-way ANOVA statistical analysis was applied to analyze the effect of four considered factors (bur wear degree, time of measurement, tooth number, and tooth location) on the pulpal blood flow (PBF). A significant increase in pulpal blood flow compared to the baseline was recorded immediately after preparation (p < 0.01), at 24 h (p < 0.01), and at 7 days (p < 0.05) in both groups, but more pronounced in the case of burs at the 5th use. The blood flow was significantly higher in upper jaw teeth, irrespective of the measurement time. In conclusion, the use of worn-out diamond burs produces lasting modifications in the pulpal blood flow of teeth that undergo prosthetic crown preparation. ISRCTN registry: ISRCTN49594720.

Comparative Evaluation of the Efficiency of Polymer Bur, Cera Bur, and Tungsten Carbide Bur in Dentin Caries Excavation of Mandibular Primary Molars: An In vivo Study.

Conservative caries removal has become an integral part of minimally invasive dentistry (MID). Polymer and Cera burs are two feasible MID methods. The aim of the study was to compare the efficiency of Polymer, Cera, and Tungsten carbide bur in dentin caries excavation of mandibular primary molars. 45 children in the age group of 6-8 years with dentin caries, not involving pulp in the second mandibular primary molars, were selected for the study. The three burs compared were polymer bur, Cera bur, and Tungsten Carbide bur. The excavation of carious lesion was performed with each burs using a slow-speed handpiece with 500-1000rpm. Caries removal efficiency was evaluated using the Visual-Tactile method and confirmed Dye detection method. The time taken to complete the caries removal was measured using a stopwatch. The patient's pain perception was assessed using the Wong-Baker Faces Pain Rating Scale. The intergroup comparisons based on time, dye, and Wong-Baker Faces Pain Rating Scale (WBFPRS) were arrived at using Mann-Whitney and Fisher Exact tests at P < 0.0001. A statistical significance between the three groups on the time taken for caries removal at P < 0.0001. No statistical significance was observed between the three groups for caries removal efficiency and pain perception using the dye and WBFPRS scores at P > 0.001. Cera burs had shown high caries removal efficiency, which had taken less time in the excavation, with reduced pain perception followed by Tungsten Carbide bur and the polymer bur in mandibular primary molars.

Effect of milling procedures in CAD-CAM systems on the color changes of CAD-CAM polymethyl methacrylate resin material as interim material.

PURPOSE: This study aimed to investigate the effects of new and used burs on CAD-CAM PMMA resin color changes following thermocycling. MATERIALS AND METHODS: Twenty disk-shaped specimens (10 × 2 mm) were made using a single brand of CAD-CAM polymethyl methacrylate resin (Polident) for the color test. Group N consisted of half of the specimens that were machined using the new tungsten carbide bur set, and Group U consisted of the specimens that were milled using the used bur set (500 machining time). A color test was performed on the specimens both before and after thermocycling. For the statistical analysis, the Kruskal-Wallis and Dunn Pairwise Comparison tests were employed. RESULTS: The ∆E* value of specimens (2.057) milled with the used bur was higher than those of specimens milled with the new bur (0.340), but this value is within clinically acceptable limits. After thermocycling, specimens milled with the utilized burs had the greatest L* (93.850) and b* (5.000) values. After thermocycling, statistically significant differences were discovered between Group N and Group U as well as between specimens milled with the utilized bur before and after thermocycling. CONCLUSION: Thermocycling process have an effect on the mean ∆E values of specimens milled with the used carbide bur, but these ∆E* values were not statistically significant. CLINICAL SIGNIFICANCE: The color and clinical performance of CAD-CAM restorations may be affected by variations in CAD-CAM milling bur properties, particularly those related to their frequent use.

Evaluation of the Pulp Chamber Temperature during Tooth Veneer Preparation Using Burs with Different Degrees of Wear-A Preliminary In Vitro Study.

The heat produced during tooth preparation could be a source of damage for dental pulp, and many variables are involved in this process. The aim of this in vitro study was to evaluate whether the different degrees of wear of the diamond burs significantly influenced the temperature changes in the pulp chamber during tangential veneer preparation. The sample comprised 30 intact permanent monoradicular teeth, randomly assigned to three study groups of 10 teeth each, of which 5 had the pulp tissue preserved and 5 had thermoconductive paste in the pulp chamber. For prosthetic preparation, we used new burs in the first group, burs at their fifth use in the second group, and burs at their eighth use for the third group. The pulp chamber temperature was evaluated at the start, after one minute, and after three minutes of preparation, using a k-type thermocouple. The results of the three-way ANOVA and Tukey post hoc comparisons showed a highly significant effect of the time of measurement, while the pulp condition and the degree of wear of the burs had no effect. In conclusion, the different degrees of wear of conventional diamond burs do not produce statistically significant different changes in the pulp chamber temperature.

Comparative Evaluation of a Dynamic Navigation System versus a Three-dimensional Microscope in Retrieving Separated Endodontic Files: An In Vitro Study.

INTRODUCTION: This study aimed to compare the effectiveness of a dynamic navigation system and a three-dimensional microscope in retrieving broken rotary Nickel-Titanium files when using trepan burs and the extractor system. MATERIALS AND METHODS: Thirty maxillary first bicuspids with 60 separate roots were split into 2 comparable groups based on a comprehensive cone beam computed tomography analysis of the root length and curvature. After standardized access opening, glide paths, and patency attainment with the K file (sizes 10 and 15), the teeth were arranged on 3D models (three per quadrant, six per model). Subsequently, controlled-memory heat-treated Nickel-Titanium rotary files (#25/0.04) were notched 4 mm from the tips and fractured at the apical third of the roots. The C-FR1 Endo file removal system was employed under both guidance to retrieve the fragments, and the success rate, canal aberration, treatment time, and volumetric changes were measured. The statistical analysis was performed using IBM SPSS software at a significance level of 0.05. RESULTS: The microscope-guided group had a higher success rate than the dynamic navigation system guidance, but the difference was insignificant (P > .05). In addition, the microscope-guided drills resulted in a substantially lower proportion of canal aberration, shorter time to retrieve the fragments and less change in the root canal volume (P < .05). CONCLUSION: Although dynamically guided trephining with the extractor can retrieve separated instruments, it is inferior to three-dimensional microscope guidance regarding treatment time, procedural errors, and volume change.

Comparison of insertion torque, implant stability quotient and removal torque, in two different implant designs with and without osseodensification. - An ex vivo bench top study.

Background: Primary stability is an important factor in influencing the outcome of dental implants. Osteotomy modification techniques mentioned, include osteotomes for bone condensation, under-preparation of osteotomy and Osseodensification (OD). The objective of our twin arm study was to assess how two different implant designs respond to conventional osteotomy drilling and how these values obtained compare with OD. Materials and methods: The study comprised a total of 80 implants inserted in pig tibia bone. Group 1a (n = 20) consisted of tapered internal implants and group 1b (n = 20) consisted of tapered pro implants, both inserted with conventional drilling. Group 2a (n = 20) consisted of tapered internal implants and group 2b (n = 20) consisted of tapered pro implants, both inserted with OD. Each implant inserted was measured for implant stability quotient (ISQ), insertion torque and removal torque. Results: Group 1a showed a significantly lower ISQ, mean insertion and removal torque and as compared to Group 1b. Group 2a and 2b had comparable mean values for all the three parameters. Inter-group comparison showed a higher ISQ and insertion torque value for group 2 than group 1. Intra-group assessment showed a significantly lower value for all parameters for sub-group a than b. Conclusions: OD enhances primary stability of implants in bone; but when no OD is used, the tapered pro implant design offers a better primary stability. This may be attributed to the active thread design.

Estudo comparativo com microscópio a laser confocal da superfície do esmalte após a aplicação de diferentes técnicas de remoção do material de adesão dos bráquetes / Comparative study with confocal laser microscopy of the enamel surface after the application of different techniques for removing the adhesion material from the brackets

Resumo O objetivo desta pesquisa foi avaliar e quantificar a rugosidade do esmalte dentário após a remoção do adesivo residual ao retirar os bráquetes. Em 30 pré-molares humanos clinicamente saudáveis, foi realizada a colagem de bráquetes no centro da face vestibular. Após 24 horas, foram descolados e foi realizado o polimento do adesivo residual com três métodos diferentes: fresa multilaminada (12 lâminas) tronco-cônico com instrumentos rotativos em alta velocidade irrigada com água; fresa redonda com instrumentos rotativos em baixa velocidade (contra ângulo) sem irrigação e fresa de fibra de vidro com instrumentos rotativos em baixa velocidade (contra-ângulo) sem irrigação. Os elementos dentários foram observados com microscópio laser confocal antes da colagem dos bráquetes. Após a sua retirada e remoção do adesivo residual, a superfície do esmalte foi observada novamente com o microscópio laser confocal, e foi utilizado o software digital OLYMPUS OLS-4100 para realizar uma reconstrução tridimensional e medir a rugosidade deixada pelos diferentes métodos de polimento. Os resultados indicaram que a fresa multilaminada em alta velocidade irrigada com água é a que deixa a superfície com parâmetros de rugosidade mais baixos. Portanto, a fresa multilaminada seria o método mais indicado para eliminar a resina residual após a retirada dos bráquetes ao final de um tratamento ortodôntico (AU)

Abstract The aim of this research was to evaluate and quantify the roughness of the dental enamel after removing the residual adhesive when removing the brackets. In 30 clinically healthy human premolars, brackets were bonded in the center of the buccal face, which were detached in 24 hours, and the residual adhesive was polished with three different methods: multi-laminated bur (12 blades) conical trunk with rotary instruments in high speed irrigated with water, round milling cutter with low-speed rotary instruments (contra-angle) without irrigation, and glass milling (Fiber Glass) with low-speed rotary instruments (contra-angle) without irrigation. The dental elements were observed with a confocal laser microscope before bracket bonding. After its removal and removal of the residual adhesive, the enamel surface was observed again with the confocal laser microscope, and the OLYMPUS OLS-4100 digital software was used to perform a three-dimensional reconstruction and measure the roughness left by the different polishing methods. The results indicated that the multi-laminated cutter at high speed, irrigated with water, is the one that leaves the surface with lower roughness parameters. Therefore, the multilaminated bur would be the most suitable method to eliminate residual resin after removing brackets at the end of an orthodontic treatment. (AU)

Evaluation of dentin microroughness and composite bond strength after multiple uses of diamond burs / Evaluación de la micro rugosidad dentinaria y la resistencia adhesiva de composites tras múltiples usos de fresas de diamante

Abstract Using a bur multiple times to prepare dental structure may produce a smoother final surface on dentin than a new one. This superficial roughness may affect adhesion with resin-based materials by modifying the substrates' characteristics. The aim of this study was to evaluate the effect of multiple uses of diamond burs on dentin's superficial microroughness and bond strength with resin composite when using a self-etch adhesive. Diamond dental burs were used to simulate a preparation (dentin flat surface) on extracted third molars. Samples were distributed into groups according to burs' number of previous uses as follows: 0, 1, 5 and 10. Scanning electron microscopy images at 70x, 350x, and 1000x were used to illustrate burs' deformation. Each specimen's dentin microroughness was measured three times to compare between experimental groups and the micro-shear bond strength test (n=15) was performed for the 0 and 10 uses groups using a universal adhesive in a self- etching mode. Diamond crystals wear and dislodgements were evident among groups where the burs were used more times. As the number of uses increased the mean microroughness of the dentin surface decreased with significant differences between the 0 and 10 uses groups. No statistical differences between experimental groups resulted from bond strength tests. When using a universal adhesive in a self-etching mode, the number of previous uses of a diamond bur seems to have no significant effect on dentin/resin composite bond strength.

Resumen El uso de una fresa múltiples veces para preparar la estructura dental puede producir una superficie final más lisa en la dentina que una fresa nueva. Esta rugosidad superficial modifica las características del sustrato y puede afectar la adhesión con materiales resinosos. El objetivo de este estudio fue evaluar el efecto de los múltiples usos de las fresas de diamante sobre la micro rugosidad superficial de la dentina y la resistencia adhesiva con la resina compuesta cuando se utiliza un adhesivo de autograbado. Se utilizaron fresas dentales de diamante para simular una preparación (superficie plana de la dentina) en terceros molares extraídos. Las muestras se distribuyeron en grupos según el número de usos previos de las fresas de la siguiente manera: 0, 1, 5 y 10. Se utilizaron imágenes de microscopía electrónica de barrido a ×70, ×350 y ×1000 para ilustrar la deformación de las fresas. Se midió la micro rugosidad de la dentina de cada espécimen tres veces para comparar entre los grupos experimentales y se realizó la prueba de resistencia a la adhesión por micro cizallamiento (n=15) para los grupos de 0 y 10 usos utilizando un adhesivo universal en modo de autograbado. El desgaste de los cristales de diamante y los desprendimientos fueron evidentes entre los grupos en los que las fresas se utilizaron más veces. A medida que aumentaba el número de usos, la micro rugosidad media de la superficie de la dentina disminuyó, con diferencias significativas entre los grupos de 0 y 10 usos. En las pruebas de resistencia adhesiva no se observaron diferencias estadísticas entre los grupos experimentales. Cuando se utiliza un adhesivo universal en modo de autograbado, el número de usos previos de una fresa de diamante no parece tener un efecto significativo en la resistencia de la unión dentina/resina del composite.

Titanium implant surface roughness after different implantoplasty protocols: A laboratory study.

OBJECTIVE: To compare the surface roughness of sandblasted, large grit, acid-etched (SLA) surfaced titanium discs, after implantoplasty (IP) with different combinations of rotating instruments without or with the subsequent use of a silicone polisher. METHODS: Titanium discs (n = 12 per group) with an SLA surface were treated with the following IP protocols: (1) Tungsten carbide bur sequence from company 1 (Komet Dental) without or with polishing (P) with a silicone polisher (Brownie®), (2) tungsten carbide bur sequence from company 2 (Hager & Meisinger GmbH) without or with P, and (3) diamond bur sequence (125, 40, 15-µm grit) without or with P. Pristine turned (T) and SLA titanium discs were used as negative and positive controls, respectively. Surface roughness measurements were taken with a contact profilometer rendering Ra and Rz values. RESULTS: All IP protocols, even without P, resulted in significantly reduced surface roughness compared to the SLA group. The tungsten carbide bur protocols, even without P, resulted in a surface roughness similar to or significantly lower than that in the T group in terms of Ra and Rz , respectively. IP with the diamond bur sequence resulted in a significantly rougher surface compared to that achieved with the carbide burs. In all IP groups, P with a silicone polisher resulted in a significantly smoother surface. CONCLUSIONS: IP with dedicated tungsten carbide burs without or with the subsequent use of a silicone polisher resulted in a surface roughness similar to or significantly lower than that of commercially available turned surfaces. IP with a diamond bur sequence required additional polishing to achieve a comparable surface roughness to that of commercially available turned surfaces.

Comparison of the C-Reactive Protein Level and Visual Analog Scale Scores between Piezosurgery and Rotatory Osteotomy in Mandibular Impacted Third Molar Extraction.

This study aimed to compare the C-reactive protein level and visual analog scale scores of piezo- and rotatory-based surgical extraction of the third molar. As a split-mouth study, the comparative groups consisted of 25 patients, each of whom underwent surgical removal of the third molar by piezo on one side and rotatory bur on the other side. C-reactive protein levels were quantitatively assessed (enzyme-linked immunosorbent assay) before and immediately post-extraction. The immediate postoperative blood sample (baseline) C-reactive protein levels were compared with 24 h and 72 h post-op samples, both within and between the groups. Pain was assessed using the visual analog scale at 24 h and 72 h post-operatively. The C-reactive protein levels were lower in the piezo group than in the rotatory group, although the difference was not significant (p > 0.05). The visual analog scale score was significantly (p < 0.01) lower in the piezo group than in the rotatory group. The C-reactive protein levels increased in both the rotary and piezo groups from the pre-op to the immediate post-op value, but in the piezo group, the levels dropped back after 24 h. On the contrary, in the rotatory group, the C-reactive level kept increasing until 24 h; the visual analog scale score dropped significantly from 24 to 72 h for both the rotatory and piezo groups. Surgical techniques that could spare the surrounding soft tissues, such as the piezo, could aid in reducing overall postoperative morbidity.

Implant Placement Post Maxillary Sinus Lift Using Osseodensification Concept: A Case Report.

Pneumatisation of the maxillary sinus is a roadblock to the successful placement of endosseous implants in the posterior maxilla. It is mandatory that the sinus has to be elevated to facilitate implant placement, for which the operating clinician should be well versed with the anatomy of the sinus to avoid intraoperative mishaps. Many techniques of sinus augmentation have been tried and tested with successful outcomes. This article presents a report of a 60-year-old female who had root stumps in relation to upper left first maxillary molar. She wanted an implant to replace the root stumps, however, on cone-beam computed tomography (CBCT) examination the sinus was pneumatised and required augmentation. The root stumps were extracted and after a six-month waiting window, she was treated with an indirect sinus augmentation procedure using Densah™ burs (Jackson, MI: Versah, LLC) after which an implant (5 mm x 8 mm) was placed with good osseointegration at three-month follow-up. The Densah™ bur facilitated sinus lift procedure is a good option for pneumatised sinuses with inadequate residual bone height.

Efficacy of various decontamination methods and sterilization on contaminated and inoculated diamond-coated burs.

The objective of this study was to evaluate the efficacy of various decontamination methods and subsequent sterilization on contaminated and inoculated diamond-coated burs. One hundred forty new diamond-coated burs and 120 extracted human molars were utilized in this study. The burs were divided into 7 groups (n = 20): 1, positive control; 2, negative control; 3, new, unused burs; and 4 to 7, burs subjected to various combinations of cleaning methods (manual cleaning, use of a cleaning stone, and/or ultrasonic cleaning) after contamination. In all of the groups except group 3, the burs were sterilized and used to abrade the enamel and dentin of the sterilized extracted teeth. In groups 1 and 4 to 7, the burs were subsequently inoculated with 1 of the following microorganisms: Enterococcus faecalis (ATCC 19433), Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 15442), or Geobacillus stearothermophilus (ATCC 7953). Twenty-four hours after inoculation, the burs in group 2 and groups 4 to 7 were subjected to the cleaning treatments and sterilized with steam. The burs in all 7 groups were then cultured for bacterial contamination. No growth of any bacterial type was observed in any of the groups except the positive control group. The use of a cleaning stone in combination with manual or ultrasonic cleaning resulted in the least amount of remaining tooth debris on the diamond-coated burs. The contaminated and inoculated diamond-coated burs tested in this study were successfully sterilized, and the tested bacteria were eliminated. If using a diamond-coated bur multiple times, practitioners should consider utilizing debridement with a cleaning stone followed by either manual or ultrasonic cleaning and then by a single cycle of steam sterilization.

Clinical and Microbiological Assessment of Carisolv and Polymer Bur for Selective Caries Removal in Primary Molars.

AIM AND OBJECTIVE: To assess the efficacy of the new Carisolv system and Polymer bur (SmartbursII®) for selective caries removal in primary molars clinically and microbiologically, compared with the conventional mechanical method. MATERIALS AND METHODS: Sixty children with class I active carious lesions were selected. The children were randomly allocated to three groups (n = 20) according to the caries removal method. Under rubber dam isolation, dentin samples were taken before and after caries removal for microbial culture. Time spent in each technique was recorded. The clinical efficacy of caries removal was verified using caries detector dye. Patient satisfaction toward the treatment was evaluated using a facial image scale. RESULTS: The median of caries detector dye scores was significantly lower in the conventional group compared to others (p value < 0.05). The mean time for caries removal was the longest with Carisolv (p value < 0.05). The median of facial image scale scores was significantly higher in the conventional group compared with others (p value < 0.05). The mean total viable bacterial count after caries removal was significantly higher in polymer bur group compared with others (p value < 0.05). While, there was no significant difference between Carisolv and conventional groups (p value > 0.05). CONCLUSION: The clinical efficacy of caries removal was highest with the mechanical method. Carisolv took the longest time for caries removal. Patient satisfaction was higher with Carisolv and polymer bur than the mechanical method. The antimicrobial efficacy of Carisolv and the mechanical method was higher than the polymer bur. CLINICAL SIGNIFICANCE: Carisolv is a viable alternative to the mechanical method in the management of dental caries, especially in children. Further studies are needed to assess the efficacy of caries removal by SmartbursII®. HOW TO CITE THIS ARTICLE: Asal MA, Abdellatif AM, Hammouda HE. Clinical and Microbiological Assessment of Carisolv and Polymer Bur for Selective Caries Removal in Primary Molars. Int J Clin Pediatr Dent 2021;14(3):357-363.

Cutting Efficiency of Welded Diamond and Vacuum Diffusion Technology Burs and Conventional Electroplated Burs on the Surface Changes of the Teeth - An In vitro Study.

CONTEXT: Welded diamond and vacuum diffusion technology (WDVDT) burs in comparison to electroplated burs claim to approach the solution of dental hard tissues by increased cutting efficiency, decreasing the overheating of oral tissues and thus reducing the microcracks on the prepared tooth surface. AIMS: This study aimed to evaluate the cutting efficiency of two different rotary diamond burs used for tooth preparation with their repeated usage on the surface changes of the prepared tooth. SETTINGS AND DESIGN: This in vitro comparative study evaluated the cutting efficiency and surface changes of the teeth prepared with conventional electroplated burs and WDVDT burs. SUBJECTS AND METHODS: Thirty freshly extracted, healthy, noncarious human premolars were divided into Group A and Group B with 15 each, and were further subdivided into three subgroups depending on the different usage intervals as first, fifth, and tenth (A1-A3 and B1-B3). The surface of each prepared specimen was evaluated quantitatively using a surface profilometer, and qualitative analysis was done using a scanning electron microscope. STATISTICAL ANALYSIS USED: Two-way ANOVA and Turkey's multiple post hoc tests were used. RESULTS: The mean surface roughness of Groups A1, A2, and A3 was 1.50 ± 0.40, 2.39 ± 0.39, and 2.65 ± 0.65 Ra, respectively. The mean surface roughness of Groups B1, B2, and B3 was 0.76 ± 0.23, 0.92 ± 0.10, and 1.24 ± 0.07 Ra, respectively. The mean surface roughness of the prepared tooth surface was significantly higher in Group A and its subgroups when compared to that of Group B and its subgroups. CONCLUSIONS: The study results showed that surface roughness was considerably lesser and also had less wear and increased cutting efficiency of tooth preparations using burs made with WDVDT compared to the preparations using conventional electroplated burs.

Development, Characterization, and Clinical Investigation of a New Topical Emulsion System Containing a Castanea sativa Spiny Burs Active Extract.

The study focused on the development and characterization of an O/W emulsion for skincare containing Castanea sativa spiny burs extract (CSE) as functional agent. The emulsion was stable and had suitable physicochemical and technological properties for dermal application and CSE showed no cytotoxicity in spontaneously immortalized keratinocytes (HaCaT) at active concentrations. A single-blind, placebo-controlled, monocentric study was designed to evaluate the skin tolerability and the skin performance of the CSE-loaded emulsion on healthy human volunteers. An improvement was observed in skin biomechanical properties such as hydration, skin elasticity and a reduction in the periorbital wrinkles in 30 days without altering the skin barrier function, sebum, pH, and erythema values. A significant skin moisturizing effect was detected while the skin barrier function was preserved. The selected natural ingredient combined with the designed formulation and the optimized preparation method has led to a final product that satisfies the physico-chemical and technological requirements underlying the safety of use and the formulative stability over time. With no negative skin reactions and highly significant effects on skin elasticity, wrinkles, and moisturization, the CSE-based emulsion achieved very satisfying outcomes representing a promising functional formulation for skin care.

A dynamic surgical navigational approach for immediate implantation and transcrestal sinus augmentation.

Real-time dynamic navigation shows various advantages over static guides in the placement of dental implants. The goal of this article is to highlight a safe and alternative approach for transcrestal sinus augmentation and immediate implantation by dynamic navigation. It elaborates and defines numerous advantages of the trace and place workflow over the fiducial technique in dynamic navigation. The usage of osseodensifying burs were shown to have higher bone-implant contact, stability, and insertion torque. Their application allows drill-tip calibration that can thus be used for dynamic navigation allowing a real-time surgical evaluation for the implant placement. This article describes a novel technique for transcrestal sinus augmentation during implant placement with osseodensifying burs using dynamic navigation.

Precision Dermabrasion of Small Areas of Vitiliginous Skin Using Dental Diamond Burs.

Dermabrasion is important step in any vitiligo surgery. Unfortunately, it is not possible to derma abrade very small area with conventional burs available. The present paper highlights the use of dental burrs in such situations.

Effects of ultrasonic refinement on endodontic access cavity walls: A microcomputed tomography analysis.

OBJECTIVES: The present study aimed in assessing the coronal defects after access cavity finishing and refinement by micro. METHODS: Access cavities on thirty molars were prepared using a diamond bur. To finish and refine the access cavity, the Endo-Z was used in group 1 (n=15) and Start X 1 in group 2. Preparation time was recorded. A micro-CT scan was done before and after access preparation. Formation and location of the new defects were registered, the extension of defects calculated and the direction of the extension registered, preparation time and surface roughness determined (P < 0.05). RESULTS: Preparation time was significantly higher with ultrasonics (P <0.001). Internal walls showed smoother surfaces for Endo-Z group. Newly counts and extension length of defects weren't significantly different between groups (P > .05). CONCLUSION: Ultrasonic tips induced new cracks. Both instruments caused the extension of cracks. Ultrasonic tips requires more time and results in significantly rougher surfaces.

Characterization and toxicity evaluation of air-borne particles released by grinding from two dental resin composites in vitro.

OBJECTIVE: The project aims to evaluate whether inhalation of particles released upon grinding of dental composites may pose a health hazard to dentists. The main objective of the study was to characterize the dust from polymer-based dental composites ground with different grain sized burs and investigate particle uptake and the potential cytotoxic effects in human bronchial cells. METHODS: Polymerized blocks of two dental composites, Filtek™ Z250 and Filtek™ Z500 from 3M™ ESPE, were ground with super coarse (black) and fine (red) burs inside a glass chamber. Ultrafine airborne dust concentration and particle size distribution was measured real-time during grinding with a scanning mobility particle sizer (SMPS). Filter-collected airborne particles were characterized with dynamic light scattering (DLS) and scanning electron microscopy (SEM). Human bronchial epithelial cells (HBEC-3KT) were exposed to the dusts in dose-effect experiments. Toxicity was measured with lactate dehydrogenase (LDH) assay and cell counting kit-8 (CCK8). Cellular uptake was observed with transmission electron microscopy (TEM). RESULTS: Airborne ultrafine particles showed that most particles were in the size range 15-35 nm (SMPS). SEM analysis proved that more than 80% of the particles have a minimum Feret diameter less than 1 µm. In solution (DLS), the particles have larger diameters and tend to agglomerate. Cell toxicity (LDH, CCK8) is shown after 48 h and 72 h exposure times and at the highest doses. TEM showed presence of the particles within the cell cytoplasm. SIGNIFICANCE: Prolonged and frequent exposure through inhalation may have negative health implications for dentists.

Antioxidant and In Vitro Preliminary Anti-Inflammatory Activity of Castanea sativa (Italian Cultivar "Marrone di Roccadaspide" PGI) Burs, Leaves, and Chestnuts Extracts and Their Metabolite Profiles by LC-ESI/LTQOrbitrap/MS/MS.

The Italian "Marrone di Roccadaspide" (Castanea sativa), a labeled Protected Geographical Indication (PGI) product, represents an important economic resource for the Italian market. With the aim to give an interesting opportunity to use chestnuts by-products for the development of nutraceutical and/or cosmetic formulations, the investigation of burs and leaves along with chestnuts of C. sativa, cultivar "Marrone di Roccadaspide", has been performed. The phenolic, tannin, and flavonoid content of the MeOH extracts of "Marrone di Roccadaspide" burs, leaves, and chestnuts as well as their antioxidant activity by spectrophotometric methods (1,1-diphenyl-2-picrylhydrazyl (DPPH), Trolox Equivalent Antioxidant Capacity (TEAC), and Ferric Reducing Antioxidant Power (FRAP) have been evaluated. Furthermore, a cell-based antioxidant in vitro test along with in vitro assays for the evaluation of the ability to reduce nuclear factor-kappa B (NF-κB) activation and nitric oxide (NO) production have been carried out. In order to identify the secondary metabolites responsible for the high phenolic content and the strong antioxidant activity shown by leaves and burs extracts, and to highlight the differences between their chemical composition, the analysis of the metabolite profile of the MeOH extracts obtained from both by-products and chestnuts by liquid chromatography coupled to electrospray ionization and multiple-stage linear ion-trap and Orbitrap high-resolution mass spectrometry (LC-(-)ESI/LTQOrbitrap/MS/MS) has been performed. LC-MS analysis allowed the identification of different classes of specialized metabolites including hydrolyzable tannins, flavonoids, ellagic acid and phenol glucoside derivatives, and triterpenoids as well as polar lipids. Our results show how the antioxidant activity of the extracts can be correlated to their high tannins and flavonoids content while polar lipids occurring in the MeOH extract of the leaves could contribute to determining its higher anti-inflammatory activity.