Longitudinal, Randomized, and Parallel Clinical Trial Comparing a Violet Light-Emitting Diodes System and In-Office Dental Bleaching: 6-Month Follow-Up.

Objective: This in vivo study compared two bleaching techniques with regard to the degree of tooth sensitivity (TS), color change, and treatment stability for a 6-month follow-up period. Materials and methods: Sixty volunteers were selected according to inclusion and exclusion criteria and submitted to in-office bleaching. For group 1, we performed one bleaching session with a 35% hydrogen peroxide gel and a second bleaching session after 7 days; for group 2, we performed two bleaching sessions with two applications per session, each session with a 7-day interval, using a light-emitting diodes (LEDs) device emitting violet light (405-410 nm) without employing peroxide-containing bleaching gel. TS was recorded immediately before and immediately after each bleaching session using the Variance Analogic Scale. The color of upper central incisors and upper canines at baseline was recorded immediately after each bleaching session, after 15, 30, and 180 days, with a value-oriented shade guide used by two well-trained observers. Results: The two whitening protocols results were similar regarding the immediate effectiveness and 6-month stability of tooth whitening. Dental bleaching with violet LED did not promote postoperative pain sensitivity at any of the evaluated times. However, dental bleaching performed with 35% hydrogen peroxide promoted higher postoperative pain sensitivity. Conclusions: The violet light alone provided dental bleaching and had the clinical advantage of promoting less immediate postoperative sensitivity; however, an unwanted repigmentation occurred after dental bleaching with light alone.

Mechanical Properties of the Mandible in Postmenopausal Women Under Aledronate Treatment.

AIMS: This study evaluated the mechanical properties of mandibular bone tissue retrieved from postmenopausal women under alendronate treatment. METHODS: Twenty postmenopausal women were divided into two groups: healthy postmenopausal subjects (control group) and osteoporotic subjects treated with alendronate (alendronate group). Mandibular bone samples were retrieved with a trephine bur at the time of dental implant placement and fixed in 4% formalin. Samples were processed for hard tissue histology, and the bone surface was analyzed for nanohardness measurement. Nanohardness and elastic modulus were evaluated by using a Berkovich tip with elastic modulus of 1.016x106 MPa, Poisson coefficient of 0.3, and a load of 100 mN. Each cycle was configured with a load time of 18 seconds (speed of 1 mN/second), the discharge time of 18 seconds, and a rest time of 5 seconds during indentation at a depth of 10 µm. RESULTS: The control group presented the highest values for nanohardness and elastic modulus (p less than 0.05) in relation to the osteoporotic subjects. CONCLUSIONS: Within the limitations of the study, it can be concluded that treatment with alendronate negatively influenced the mechanical properties of mandibular bone in postmenopausal women by reducing bone nanohardness and elastic modulus.

Ultraviolet-C decontamination of a dental clinic setting: required dose and time of UVC light / Utilização de radiação ultravioleta-C para descontaminação de um consultorio odontológico: tempo e dose de UVC necessária

Viruses can spread to the environment, and it can be challenging to clear it. A direct approach to limit airborne transmission of pathogens in dental clinic offices is to inactivate viruses within a short time of their production and block the person-to-person transmission routes in dental clinics. For this, we can use chemical substances on surfaces and germicidal ultraviolet light (UV), typically at 254 nm, for complementary disinfection of surfaces and air contaminated by aerosols produced by high-speed handpiece or ultrasound scaler. Based on the literature review and the similarity of Sars-Cov-2 with other previously studied corovaviruses, COVID-19 is sensitive to UV irradiation that can break the genome of this virus, inactivating it. In our study, we performed the calculation of the time required to decontaminate a dental care room between each patient change. We can conclude that the use of UVC can be incorporated into the dental care routine to reduce cross contamination. (AU)

Os vírus podem se espalhar para o meio ambiente e pode ser um desafio eliminá-lo. Uma abordagem direta para limitar a transmissão aérea de patógenos nos consultórios de clínicas odontológicas é inativar os vírus o mais rápido possivel após sua produção e bloquear as rotas de transmissão de pessoa para pessoa nas clínicas odontológicas. Para isso, podemos usar substâncias químicas para limpar as superfícies e luz ultravioleta (UV) germicida (UV), normalmente a 254 nm, para desinfecção complementar de superfícies e ar contaminado por aerossóis produzidos pelo altarotação ou ultrassom periodontal. Com base na revisão de literatura e na semelhança do SarsCov-2 com outros corovavirus previamente estudados, o COVID-19 é sensível à irradiação UV que podem quebrar o genoma desse vírus, inativando-o. Em nosso estudo, realizamos o cálculo de tempo necessário para descontaminar uma sala de atendimento odontológico entre cada troca de paciente. Podemos concluir que a utilização de UVC pode ser incorporada à rotina de atendimento odontológico para reduzir a contaminação cruzada entre atendimentos. (AU)

Adhesive/silane application effects on bond strength durability to a lithium disilicate ceramic.

OBJECTIVE: To test the effects of different adhesive protocols and silane application on the adhesive durability to a Lithium Disilicate reinforced glass ceramic. METHODS: Forty disks of 13 mm diameter (E.max Press) were used. After etching with 9.5% HF for 20 seconds, disks were randomly assigned into 4 groups according to the adhesive/silane protocol: silane application only (SIL); silane application followed by adhesive (SILXP-XP Bond); silane-containing adhesive (SBU-ScotchBond Universal); silane application followed by silane-containing adhesive (SILSBU). Four resin composite cylinders of 1-mm diameter and 3-mm height were made on each ceramic disk and tested in shear. Specimens were stored in water for 24 hours or 12 months prior to testing. Results were statistically analyzed by two-way ANOVA and Tukey test. RESULTS: After 24 hours, the highest SBS values were observed for SILXP and SILSBU. However, after 12 months, SILXP and SILSBU presented a significant reduction in SBS, while the highest SBS were observed for SIL. For SBU, no significant reduction in SBS was observed, however, it showed the lowest SBS after 12 months. CONCLUSIONS: Regardless of the presence of silane in the composition of SBU, previous silane application is still recommended prior to cementation of Lithium Disilicate. CLINICAL SIGNIFICANCE: The application of silane as a separate step is recommended prior to cementation of Lithium Disilicate reinforced glass-ceramic, independent of the presence of silane within the universal adhesive solution.

Effect of different power settings of Er,Cr:YSGG laser before or after tribosilicatization on the microshear bond strength between zirconia and two types of cements.

The aim of this study was to evaluate the effect of different output powers of Er,Cr:YSGG laser and the association with tribochemical silica coating on the bond strength between zirconia ceramic and two resin cements. One hundred ninety-two zirconia ceramic bars (IPS e-max ZirCAD Ivoclar Vivadent-) were sectioned (6 × 6 × 4 mm), sintered, and randomly divided into 12 groups for each cement system according to the surface treatment (n = 8): C-without treatment (control); R-tribochemical coating + resin cement (control); 2L-laser (2.0 W) + resin cement; 2LR-laser (2.0 W) + tribochemical coating + resin cement; R2L-tribochemical coating + laser (2.0 W) + resin cement; 2.5L-laser (2.5 W) + resin cement; 2.5LR-laser (2.5 W) + tribochemical coating + resin cement; R2.5L-tribochemical coating + laser (2.5 W) + resin cement; 3L-laser (3.0 W) + resin cement; 3LR-laser (3.0 W) + tribochemical coating + resin cement, R3L-tribochemical coating + laser (3.0 W) + resin cement; and RPHO-tribochemical + resin cement + photoactivation (control). After the surface treatment, the respective primers were applied, and resin cements, Multilink N, Ivoclar Vivadent (M), and Panavia F 2.0, Kuraray Medical Inc. (P), were inserted into Tygon molds which were bonded to the zirconia bars. Each specimen received two cements bars. After 24 h of storage in a relative humidity (100%) at 37 °C, they were evaluated by the microshear test speed of 1 mm/min. The microshear values were analyzed by one-way ANOVA and Tukey's test (α = 0.05). ANOVA showed statistically significant differences among the evaluated groups. The highest bond strength was observed in RPHO, which statistically differed from all groups. The lowest bond strength was observed in M2.5L (Multilink N) and in P3LR (Panavia F 2.0). It can be concluded that the lowest power output tested was suitable and showed bond strength values similar to tribochemical silica deposition. The light curing is important to adhesion and the tribosilicatizated surface achieves similar microshear values to untreated surface in absence of light.

Er,Cr:YSGG Laser Energy Delivery: Pulse and Power Effects on Enamel Surface and Erosive Resistance.

BACKGROUND: High power lasers have been suggested as a useful tool for dental caries and erosion prevention due to the increase of enamel acid resistance. OBJECTIVE: to evaluate the effect of Er,Cr:YSGG (erbium,chromium:yttrium, scandium, gallium, garnet) laser irradiation pulse frequency and power on enamel surface and acid erosion resistance. METHODS: By combining pulse frequency (5-75 Hz) and power settings (0.10-1.00 W), 20 irradiated groups and one nonirradiated control group were tested. A total of 63 bovine enamel blocks (n = 3/group) were prepared for surface hardness and roughness evaluation, performed in three phases: baseline, after irradiation, and after erosive challenge. Enamel blocks were irradiated with Er,Cr:YSGG laser with MZ8 tip (iPlus; Waterlase, Biolase, CA) for 30 sec according to experimental group and submitted. Erosive challenge consisted of four cycles alternating immersion in 0.01 M HCl (5 mL/mm2; 2 min; at 37°C) and immersion in artificial saliva for 3 h. Analysis of variance (three-way ANOVA), Tukey's test, and Pearson correlation were performed for the statistical analysis (p < 0.05). RESULTS: After irradiation, groups irradiated with pulse frequency of 10 and 15 Hz showed a decrease in surface hardness. After erosive challenge, 5 and 75 W groups showed increase in surface hardness; 0.25, 0.5, 0.75, and 1 W groups showed minor alterations in surface roughness. CONCLUSIONS: the irradiation of Er,Cr:YSGG laser with different parameters of power and pulse frequency settings may alter enamel surface and erosive resistance differently. Pulse frequency of 30 Hz and power of 0.50 W was considered the best parameter to prevent enamel acid erosion.

Analysis of Human Tooth Pulp Chamber Temperature After 670 nm Laser Irradiation: In Vitro Study.

OBJECTIVE: One of the limiting factors of employing laser radiation on dental therapies is the potential of causing thermal injuries to pulp tissues. The purpose of this study was to evaluate intra-chamber temperature increase on extracted human teeth exposed to 670 nm wavelength InGaAlP laser diode radiation. MATERIALS AND METHODS: In vitro intra-chamber temperature measurements of 12 standardized human teeth (incisors, canines, premolars, and molars; n = 3) were taken both before and after laser radiation. A type-K thermocouple fast-response thermocouple wire with a 0.5 mm diameter probe was inserted into the tooth pulp chamber (ICEL-Manaus-brand). The laser device Lasotronic-brand InGaAlP laser diode was used to irradiate tooth enamel, perpendicularly to the external surface for 30 sec, with power of levels of 340, 272, 204, 136, and 68 mW. The measurements were taken at three time points: 0, 30 sec, and 3 min after the laser irradiation. Measurements were repeated 24 h after removal and reinsertion of the probe in the pulp chamber. The temperature gradient (ΔT in °C) was calculated (ΔT = final temperature-initial temperature) for each group. Data of ΔT were statistically analyzed by two-way analysis of variance (ANOVA) at the 95% confidence level and compared by Tukey post hoc test (α = 0.05). RESULTS: ANOVA showed statistically significant differences to the interaction of factors (p < 0.05). The highest ΔT values obtained were observed to incisors with 340 mW, 272 mW; 204 mW of power (respectively 4.7°C, 4.2°C, and 3.1°C); and canines presented the lowest ΔT (0.8°C-0.3°C) with no influence of power output. CONCLUSIONS: Since the thermal increase was observed in this study, especially in incisors, attention should be paid to avoid pulpal damage.

Bond Strength of Abraded and Non-Abraded Bleached Enamel to Resin After Er,Cr:YSGG Laser Irradiation.

OBJECTIVE: The objective of the study was to evaluate the microtensile bond strength (µTBS) of a composite resin to abraded or non-abraded bleached enamel after Er,Cr:YSGG laser irradiation and to observe the fracture patterns of the tested interfaces. MATERIALS AND METHODS: Two hundred twenty-eight bovine incisors were sectioned, resulting in 228 enamel blocks (7 × 4 × 4 mm3) that were divided into 12 groups (n = 19) according to the factors "adhesion" after bleaching (immediate adhesion; after 14 days; and a control group with adhesion on unbleached teeth); enamel "abrasion" (with or without abrasion simulating cavity preparation); and "laser" (with or without Er,Cr:YSGG laser irradiation). Bleached enamel groups were treated with 20% carbamide peroxide, 8 h/day for 21 days. Abrasion was performed with silicon carbide sandpaper. Specimens were restored with adhesive system and a composite resin (Adper Single Bond 2 and Z250; 3M ESPE). After 7 days, specimens were prepared by cutting into 1 mm beans to µTBS test performed in a universal testing machine. Fracture mode analysis was performed by using a stereoscopic loupe. The µTBS data were statistically analyzed by three-way analysis of variance with 95% confidence level and compared by running a Tukey post hoc test (α = 0.05). RESULTS: There was no statistically significant difference between triple interaction and double interactions among factors. There was no significant difference between the factors "adhesion," "abrasion," and "laser." Laser irradiation produced significantly lower bond strength values in irradiated groups compared with the non-irradiated ones. All groups had a high percentage of adhesive failures. CONCLUSIONS: Abrasion provided no benefit to bond strength of composite resins to bleached enamel. Er,Cr:YSGG (20 Hz, 0.5 W, 3.97 J/cm2) treatment reduced the bond strength of composite resins to enamel.

Evaluation of Temperature and Roughness Alteration of Diode Laser Irradiation of Zirconia and Titanium for Peri-Implantitis Treatment.

OBJECTIVE: This study investigated the effects of diode laser (gallium, aluminium, arsenide [GaAlAs]) irradiation with decontamination parameters on the temperature and roughness of yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP), titanium (TI), and sandblasted large grit acid-etched titanium (SLA). MATERIALS AND METHODS: Three groups (n = 10) of standardized disks with 5 mm diameter and 2 mm thickness were produced with Y-TZP obtained from computer-aided design and computer-aided manufacturing (CAD-CAM), machined TI and SLA. The diode laser single application (808 nm, 20 sec, 1 W, 50 Hz, t on = 100 ms, t off = 100 ms, energy density = 28.29 J/cm(2)) was performed in contact mode, on each disk. The temperature was measured by a thermosensor attached to a digital thermometer fixed to the opposite irradiated surface. The temperature gradient (ΔT) was calculated (ΔT = final temperature - initial temperature) for each group. The parameters Ra (in µm) and Sa (in µm(2)) were measured by white light confocal laser microscopy to express the surface roughness. Data of ΔT was statistically analyzed by one way ANOVA at the 95% confidence level and compared by Tukey post-hoc test (α = 0.05). Roughness data was analyzed by t test. RESULTS: The diode laser irradiation presented the following results (ΔT value): Y-TZP = 10.3°C(B); TI = 38.6°C(A), and SLA = 26.7°C(A). The ΔT values ((°)C) of the titanium groups were higher than for the Y-TZP group. For both roughness parameters (Ra and Sa), data did not show statistical significant differences to "irradiation" factor (p > 0.05) to Y-TZP and SLA. The Ra results (in µm) were: Y-TZP (control) = 0.73 (0.55); Y-TZP (irradiated) = 0.45 (0.27); SLA (control) = 0.74 (0.23); and SLA (irradiated) = 0.99 (0.33). The Sa results (in µm(2)) were: Y-TZP (control) = 1.39 (1.05); Y-TZP (irradiated) = 0.73 (0.41); SLA (control) = 0.85 (0.08); and SLA (irradiated) = 1.27 (0.44). CONCLUSIONS: Diode laser irradiation for peri-implantitis treatment increased both zirconia and TI temperature without surface roughness alterations.

In Vitro Behavior of Osteoblasts on Zirconia After Different Intensities of Erbium, Chromium-Doped: Yttrium, Scandium, Gallium, and Garnet-Laser Irradiation.

OBJECTIVE: This study investigated the osteoblastic behavior to yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) surface after different intensities of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation treatment. MATERIALS AND METHODS: Y-TZP blocks were randomized divided into 4 groups to Er,Cr:YSGG laser irradiation: group G1 = control (no laser irradiation); group G2 = 1.5 W; group G3 = 3.0 W; group G4 = 5.0 W, with air-water irrigation. The irradiated surface roughness (Sa and Ra) topography was evaluated. MC3T3-E1 osteoblast cells were cultured and seeded onto the treated surfaces at a plate density of 1 × 10 cells/mL. At the third and seventh days cell proliferation was measured by the colorimetric assay methods. The specimens were prepared to scanning electron microscope to observe adhesion and morphology of cells. RESULTS: MTT assay showed adhesion and proliferation of MC3T3-E1 cells in all groups. Compared with group G1 (control), the group G2 had a proliferation 1.4% higher (P > 0.05), the group G3 had a proliferation 3.1% higher (P < 0.05) and group G4 had a proliferation 4.5% higher (P < 0.01). After 7 days there was no difference among the groups (ANOVA, Newman-Keuls). CONCLUSIONS: Er,Cr:YSGG laser irradiation may have contributed to the greater and earlier cell spreading that was observed with the Y-TZP without alterations on surface topography.

Levels of osteoclastogenesis-related factors in the peri-implant crevicular fluid and clinical parameters of immediately loaded implants in patients with osteopenia: a short-term report.

PURPOSE: The aim of this prospective controlled study was to evaluate the influence of osteopenia on the levels of osteoclastogenesis-related factors in the peri-implant crevicular fluid (PICF) and on the clinical parameters of immediately loaded implants. MATERIALS AND METHODS: This study included 24 patients who received at least two implants in the mandible, with restorations delivered 48 hours after implant placement. Patients were divided into control (n = 11) and osteopenia (n = 13) groups. Seven days after implant placement (baseline) and 4 months after implant placement, PICF samples were obtained, and clinical parameters (Plaque Index, Gingival Index, bleeding on probing, suppuration, probing depths, clinical attachment levels) were measured. A commercially available enzyme-linked immunosorbent assay was used to analyze PICF samples for levels of soluble receptor activator of nuclear factor of κB ligand (sRANKL) and osteoprotegerin (OPG). At the 4-month follow-up visit, the implant-supported restorations were removed and periapical radiographs were acquired to evaluate bone loss around the implants. RESULTS: Eighty-eight immediately loaded implants were included in this study (38 in the control group, 50 in the osteopenia group). The RANKL and OPG levels, the RANKL/OPG ratio, and the clinical parameters were similar between the groups at both time points. However, the levels of these factors in PICF differed significantly between baseline and 4 months after surgery. CONCLUSION: Within the limitations of this short-term study, it can be concluded that osteopenia does not influence the PICF levels of osteoclastogenesis-related factors in immediately loaded implants after 4 months of loading.

Oral Streptococci Biofilm Formation on Different Implant Surface Topographies.

The establishment of the subgingival microbiota is dependent on successive colonization of the implant surface by bacterial species. Different implant surface topographies could influence the bacterial adsorption and therefore jeopardize the implant survival. This study evaluated the biofilm formation capacity of five oral streptococci species on two titanium surface topographies. In vitro biofilm formation was induced on 30 titanium discs divided in two groups: sandblasted acid-etched (SAE- n = 15) and as-machined (M- n = 15) surface. The specimens were immersed in sterilized whole human unstimulated saliva and then in fresh bacterial culture with five oral streptococci species: Streptococcus sanguinis, Streptococcus salivarius, Streptococcus mutans, Streptococcus sobrinus, and Streptococcus cricetus. The specimens were fixed and stained and the adsorbed dye was measured. Surface characterization was performed by atomic force and scanning electron microscopy. Surface and microbiologic data were analyzed by Student's t-test and two-way ANOVA, respectively (P < 0.05). S. cricetus, S. mutans, and S. sobrinus exhibited higher biofilm formation and no differences were observed between surfaces analyzed within each species (P > 0.05). S. sanguinis exhibited similar behavior to form biofilm on both implant surface topographies, while S. salivarius showed the lowest ability to form biofilm. It was concluded that biofilm formation on titanium surfaces depends on surface topography and species involved.

Impact of osteoporosis in dental implants: A systematic review.

AIM: To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects. METHODS: Extensive examination strategies were created to classify studies for this systematic review. MEDLINE (via PubMed) and EMBASE database were examined for studies in English up to and including May 2014. The examination presented a combination of the MeSH words described as follow: "osteoporosis" or "osteopenia" or "estrogen deficiency" AND "implant" or "dental implant" or "osseointegration". Assessment of clinical and/or histological peri-implant conditions in osteoporosis subjects treated with titanium dental implants. The examination included a combination of the MeSH terms described as follow: "osteoporosis" or "osteopenia" or "estrogen deficiency" AND "implant" or "dental implant" or "osseointegration". RESULTS: Of 943 potentially eligible articles, 12 were included in the study. A total of 133 subjects with osteoporosis, 73 subjects diagnosed with osteopenia and 708 healthy subjects were assessed in this systematic review. In these subjects were installed 367, 205, 2981 dental implants in osteoporotic, osteopenic and healthy subjects, respectively. The failure rate of dental implant was 10.9% in osteoporotic subjects, 8.29% in osteopenic and 11.43% in healthy ones. Bone-to-implant contact obtained from retrieved implants ranged between 49.96% to 47.84%, for osteoporosis and non-osteoporotic subjects. CONCLUSION: Osteoporotic subjects presented higher rates of implant loss, however, there is a lower evidence to strengthen or refute the hypothesis that osteoporosis may have detrimental effects on bone healing. Consequently, final conclusions regarding the effect of osteoporosis in dental implant therapy cannot be made at this time. There are no randomized clinical trial accessible for evaluation and the retrospective nature of the evaluated studies shall be taken in account when interpreting this study.

Influence of cavity preparation with Er,Cr:YSGG laser and restorative materials on in situ secondary caries development.

OBJECTIVE: The aim of this study was to evaluate the influence of cavity preparation and restorative materials containing fluorides in the prevention of secondary caries lesion development in situ. METHODS: A total of 120 blocks obtained from human teeth were divided into two groups and standardized cavities were prepared using diamond burs (DB) or Er,Cr:YSGG-laser [20 Hz, 4.0W, 55% water, 65% air (LA)]. They were divided into three subgroups according to the restorative material (n=20): glass-ionomer cement (GI), resin modified glass-ionomer (RM) or composite resin (CR). Blocks were fixed in palatal intra-oral appliances worn in situ by 20 human volunteers, who dropped 20% sucrose solution eight times daily. After 21 days, blocks were removed and restorations were cross-sectioned to evaluate microhardness [Knoop hardness number (KHN)] underneath enamel surface from 30 to 200 µm. Factors "cavity preparation," "restorative materials," and "depth" were evaluated by three way ANOVA, followed by Tukey test (p<0.05). RESULTS: The results showed lower microhardness in cavities prepared with DB than in cavities prepared with LA. At 30 µm, there were no statistical significant differences with regard to "cavity preparation" or "restorative materials" factors. In depth evaluation, the enamel microhardness progressively increased as a function of depth for the GI groups. In the groups prepared with LA at 60 µm/90 µm, there were no significant differences between GI and RM materials, whose microhardnesses were significantly higher than that of CR. CONCLUSIONS: Cavity preparation using Er,Cr:YSGG laser increases caries resistance of enamel walls, and reduce caries lesion depth development regardless of fluoride presence in the restorative material. CR showed higher caries lesion development than GI, and RM showed intermediate results.

Surface alterations of zirconia and titanium substrates after Er,Cr:YSGG irradiation.

This study investigated changes in the roughness parameters (Sa in µm(2) and Ra in µm) of yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) and large-grit sandblasted acid-etched (SLA) titanium (TI) materials after decontamination by erbium chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser irradiation. Twenty disks were analyzed in this study: 10 disks of Y-TZP (5 mm in diameter and 3 mm in height), standardized with CAD-CAM procedures, and 10 disks of SLA TI (5 mm in diameter and 4 mm in thickness). Disks were randomized into four groups (n = 5), according to whether laser irradiation was performed: Y-TZP_G1 and TI_G1 were not treated by laser (control groups), whereas Y-TZP_G2 and TI_G2 were irradiated with Er,Cr:YSGG laser (1.5 W/20 Hz, air-water cooling proportion of 80%/25%). The surface topography of the disks was analyzed by confocal light microscopy. The mean Sa and Ra values were calculated from five profiles from each group. The results were statistically analyzed by t-test at the 95% confidence level (α = 0.05). For Y-TZP, the Sa results (in mean ± SD) for Y-TZP_G1 and Y-TZP_G2 were 2.60 ± 1.1 and 0.80 ± 0.17 µm(2), respectively, and the Ra results were 2.01 ± 0.71 and 0.18 ± 0.15 µm, respectively (both p < .05). For SLA TI, the Sa results for TI_G1 and TI_G2 were 1.99 ± 0.5 and 3.37 ± 0.75 µm(2), respectively, and the Ra results were 1.78 ± 0.53 and 3.84 ± 0.63 µm, respectively (both p < .05). Er,Cr:YSGG laser irradiation alters the surface roughness of zirconia and SLA TI.

Influence of photoactivation source on restorative materials and enamel demineralization.

OBJECTIVE: The objective of this study was to evaluate the influence of the photoactivation source on the polymerization depth of restorative materials and its effects on resistance to enamel demineralization. BACKGROUND DATA: Argon-ion laser (AL) irradiation itself provides a reduced depth of caries lesions in sound enamel. METHODS: Eighteen human teeth were sectioned into 36 blocks and distributed into two groups according to the respective restorative material: resin-modified glass ionomer material (RMGI) (Vitremer-3M ESPE; A3; n=18) and composite resin (CR) (Z350-3M ESPE; n=18). Each group was subdivided into three subgroups and activated by a quartz-tungsten-halogen (QTH) lamp, an AL, or a light-emitting diode (LED) (n=6). Knoop microhardness (KHN) analysis of the materials was evaluated at two different depths: 0 and 1.6 mm from the enamel surface. The blocks were thermocycled and submitted to five demineralization-remineralization cycles at 37°C. The KHN values of the enamel surface (0 mm) were evaluated. The specimens were longitudinally sectioned, and the restorative material was evaluated at a depth of 1.6 mm. Data were evaluated by two way analysis of variance (ANOVA) and Tukey tests (p<0.05). The evaluation of subsuperficial enamel demineralization by KHN analysis was conducted by seven indentations located at 100 µm from the restored cavity. Data were evaluated by three way ANOVA and Tukey tests (p<0.05). RESULTS: Comparing the two restorative materials, the KHN values at the surface (0 mm) were greater for CR, whereas at 1.6 mm, they were greater for RMGI. In addition, there was less development of enamel demineralization around RMGI restorations than CR restorations. Moreover, there were statistically significant differences on subsuperficial enamel demineralization between the two restorative materials and between the three photoactivation methods (p<0.05); RMGI presented the highest KHN values, and QTH and AL presented the lowest. CONCLUSIONS: The photoactivation source did not influence superficial enamel demineralization, but LED activation positively influenced the subsuperficial microhardness of enamel.

Stability of implants placed in augmented posterior mandible after alveolar osteotomy using resorbable nonceramic hydroxyapatite or intraoral autogenous bone: 12-month follow-up.

PURPOSE: This prospective, controlled split-mouth study evaluated the stability of dental implants placed in the augmented mandibular areas with alveolar segmental "sandwich" osteotomies using nonceramic hydroxyapatite (ncHA) or autogenous bone. MATERIAL AND METHODS: This study included 11 bilaterally partially edentulous mandibular patients in a split-mouth design. Alveolar augmentation osteotomies were performed bilaterally with interpositional ncHA graft (test group) or interpositional intraoral autogenous bone graft (control group). After 6 months of healing, four implants (two implants in each side) were placed in each patient. Forty-four implants were inserted and loaded after 6-month healing period. At 1-year follow-up, radiographic, prosthetic, and resonance frequency analysis parameters were assessed. Success criteria included absence of pain, sensitivity, suppuration, and implant mobility; absence of continuous peri-implant radiolucency; and distance between the implant shoulder and the first visible bone contact (DIB) < 2 mm. RESULTS: After a 1-year loading period, the overall implant survival rate was 95.45%, with two implant losses (one of each group). Among the surviving implants (42 out of 44), two did not fulfill the success criteria; therefore, the implant success was 90.90%. DIB was 0.71 ± 0.70 and 0.84 ± 0.72 mm for ncHA and autogenous bone grafts, respectively (p > .05). Implant stability measurements were similar between the groups during the 12-month follow-up (p > .05). CONCLUSION: Within the limits of this study, the implants placed either in sites augmented with ncHA or autogenous bone seem to represent a safe and successful procedure, at least, after 12-month follow-up.

Effects of tobacco smoking on the survival rate of dental implants placed in areas of maxillary sinus floor augmentation: a systematic review.

OBJECTIVES: The objective of this systematic review was to evaluate the effects of smoking on the survival rate of dental implants placed in areas of maxillary sinus floor augmentation. MATERIAL AND METHODS: The Cochrane Oral Health Group's Trials Register (CENTRAL), MEDLINE and EMBASE were searched in duplicate up to, and including, October 2012 without language restrictions. Studies were considered eligible for inclusion if they involved the treatment of smokers and non-smokers with titanium implants and sinus floor elevation procedures. The Newcastle-Ottawa Scale and the Cochrane Collaboration's quality assessment tool were used for the assessment of the risk of bias in included studies. Random effects meta-analyses were used to assess the number of implants lost in smokers vs. number of implants lost in non-smokers. RESULTS: Of 3360 potentially eligible papers, eight studies were included. More than half (62.5%) of the studies found that smoking adversely affects implant survival in sites of sinus floor augmentation. Similarly, the pooled analysis indicated a statistically significantly increased risk of implant failure in smokers when the outcomes of all studies available to be included into meta-analysis were evaluated [RR: 1.87 (95% CI: 1.35, 2.58), P = 0.0001]. Conversely, a subgroup analysis including only prospective studies (3 studies) did not reveal significant differences in implant failure between smokers and non-smokers [RR: 1.55 (95% CI: 0.91, 2.65), P = 0.11]. CONCLUSIONS: Although smoking was associated with implant failure in most of individual studies and in the overall meta-analysis, the detrimental effect of smoking was not confirmed when only prospective data were assessed.

Ultimate tensile strength and microhardness of glass ionomer materials / Resistência coesiva e microdureza de materiais ionoméricos

Objective: This study evaluated the ultimate tensile strength (UTS) and microhardness (µKH) of conventional (CO) and hybrid resin-modified glass ionomer (RM). Material and methods: Nine specimens to UTS and twelve for µKHN of glass ionomer materials were obtained using special molds. The materials were manipulated and CO groups were allowed to self-cure for five minutes and RM were subjected to light-activation as indicated by manufactures through a glass slide. All specimens were dark-stored in 100% relative humidity for 24 h. For UTS test, specimens were tested in tension in a universal testing machine (crosshead speed of 1 mm/ min) until failure. For µKHN test a Knoop diamond indenter was used to make five indentations in the upper/light irradiated surface of the specimens. UTS and µKHN data were submitted to one-way ANOVA, followed by Tukey’s test (α = 5%). Results: The results for UTS were: Ionomaster: 7.0 (± 1.6) A; Maxxion R: 8.8 (± 3.7) A Vidrion R: 8.8 (± 3.9) A; ChemFil Rock: 10.7 (± 4.6) AB; Vitremer: 13.1 (± 3.3)BC; Vitrofil R: 14.9 (± 7.8)CD; Ionoseal: 14.5 (± 8.2)CD; Resiglass: 16.3 (± 2.3)D. The results for µKH: Ionomaster: 24.3 (± 6.6)B; Maxxion R: 17.7 (± 4.7) A, Vidrion R: 31.0 (± 9.4) B; ChemFil Rock: 31.1 (± 8.5)B; Vitremer: 20.3 (± 3.3) A; Vitrofil R: 16.5 (± 5.1) A; Ionoseal: 13.1 (± 8.5) A; Resiglass: 21.6 (± 5.2) A. Conclusion: It was observed that the hybrid resin-modified ionomers generally have higher cohesive strength than conventional ones, but lower microhardness

Objetivo: Este estudo avaliou a resistência coesiva (UTS) e microdureza (μKH) de materiais ionoméricos, convencional (CO) e híbrido de ionômero de vidro modificado por resina (RM). Material e Métodos: Nove amostras para UTS e doze para μKHN de materiais ionoméricos foram preparadas utilizando matrizes especiais. Os materiais foram manipulados e grupos CO sofreram a autocura durante cinco minutos e os RM foram submetidos à ativação por luz como indicado pelos fabricantes através de uma lamínula de vidro. Todos os espécimes foram armazenados no escuro, em 100 % de umidade relativa por 24 horas. Para o teste de UTS, os espécimes foram testados em tensão numa máquina de ensaios universal (velocidade de 1 mm/min ) até a falha. Para o teste μKH um diamante penetrador tipo Knoop foi usado para fazer 5 endentações na parte superior; irradiada pela luz na superfície dos espécimes. Os dados de UTS e de μKHN foram submetidos a one-way ANOVA, seguido pelo teste de Tukey (α = 5%). Resultados: Os resultados para UTS foram: Ionomaster: 7,0 (± 1,6) A; Maxxion R: 8,8 (± 3,7) A Vidrion R: 8,8 (± 3,9) A; Chemfil Rock: 10,7 (± 4,6) AB; Vitremer: 13,1 (± 3,3)BC; Vitrofil R: 14,9 (± 7,8) CD; Ionoseal: 14,5 (± 8,2) CD; Resiglass: 16,3 (± 2,3)D. Os resultados para μKH: Ionomaster: 24,3 (± 6,6) B; Maxxion R: 17,7 (± 4,7) A, Vidrion R: 31,0 (± 9,4) B; Chemfil Rock: 31,1 (± 8,5) B; Vitremer: 20,3 (± 3,3) A; Vitrofil R: 16,5 (± 5,1) A; Ionoseal: 13,1 (± 8,5) A; Resiglass: 21,6 (± 5,2) A. Conclusão: Observou-se que os híbridos de ionômero de vidro modificados por resina geralmente têm força coesiva mais alta do que os convencionais, mas menor dureza.