Preemptive use of ibuprofen and desensitizer decreases immediate tooth sensitivity after in-office bleaching: A triple-blind, randomized, placebo-controlled clinical trial.

BACKGROUND: The authors evaluated the synergistic analgesic effect of preemptive administration of 400 mg of ibuprofen (IBU) and potassium fluoride 2% (KF2), both in isolation or combination, on the painful perception of tooth sensitivity after tooth bleaching. METHODS: Fifteen patients participated in this triple-blind, randomized, placebo-controlled clinical trial. The study used a crossover design for drug administration and a split-mouth design for desensitizer agent. Four paired groups were formed: IBU plus KF2 (IBU + KF2); IBU (IBU + placebo KF); KF2 (placebo IBU + KF2), and placebo (placebo IBU + placebo KF). The outcome measure was the perception of tooth sensitivity, assessed using a visual analog scale. Data were collected at 4 different times: immediately after tooth bleaching (baseline) and after 6, 30, and 54 hours. Statistical analysis was performed using the Friedman test and relative risk. RESULTS: IBU plus KF2 was found to be more effective in reducing tooth sensitivity immediately after bleaching (baseline) compared with the placebo group (P < .05). The risk of experiencing moderate or severe tooth sensitivity was approximately 4 times higher in the placebo group than in the IBU plus KF2 group (relative risk, 4.00; 95% CI, 1.01 to 15.81; P = .025). CONCLUSIONS: The combined use of 400 mg of IBU and KF2 appears to be beneficial in managing postbleaching tooth sensitivity. It provides a superior analgesic effect compared with placebo. PRACTICAL IMPLICATIONS: The preemptive administration of IBU plus KF2 reduces tooth sensitivity after tooth whitening when compared with placebo. This clinical trial was registered in the Brazilian Clinical Trials Registry Platform. The registration number is U1111-1249-8191.

Influence of the frameworks of implant-supported prostheses and implant connections on stress distribution.

BACKGROUND: The maintenance of marginal bone integrity around dental implants continues to be a clinical challenge. It is still unclear whether loading multiple implant-supported prostheses that have different implant connections influences bone resorption. OBJECTIVES: The aim of this in vitro study was to compare stress distribution around residual edentulous ridges supported by external hexagon (EH) and Morse taper (MT) implants with screw-retained frameworks obtained with the use of different methods. MATERIAL AND METHODS: Three-element implant-supported prostheses with distal cantilevers were manufactured according to different techniques of obtaining the framework: LAS - framework sectioned and welded with a laser; TIG - framework sectioned and welded with tungsten inert gas (TIG); and CCS - framework obtained using a computer-aided design/computer-aided manufacturing (CAD/CAM) system. Occlusal and punctual loading (150 N) was applied to the cantilevers. In the photoelastic stress analysis, the fringe orders (n) were quanitified using the Tardy method, which calculates the maximum shear stress value (τ) at each selected point. RESULTS: High stress around the implants and tightening were observed in the TIG group, mainly in the crestal bone region for the EH and MT implant connections. The LAS and CCS frameworks exhibited lower stress for the MT connection under occlusal and punctual loading. CONCLUSIONS: The comparative analysis of the models showed that the MT connection type associated with the laser-welded or CAD/CAM frameworks resulted in lower stress values in the crestal bone area, suggesting the preservation of bone tissue in this region.

Analysis of implant-supported cantilever fixed partial denture: An in vitro comparative study on vertical misfit, stress distribution, and cantilever fracture strength.

PURPOSE: To evaluate the vertical misfit, stress distribution around dental implants, and cantilever fracture strength of 3-unit implant-supported cantilever fixed partial dentures (FPDs) using frameworks made from different materials and manufacturing techniques. MATERIALS AND METHODS: Forty FPDs were fabricated and divided into 5 groups (n = 8) based on the framework material used: LAS Co-Cr (Conventional casting-laser welding); TIG Co-Cr (Conventional casting -TIG welding); OP Co-Cr (Conventional casting-one-piece); CAD Co-Cr (CAD-CAM); and CAD Zr (CAD-CAM ZrO2 ). The vertical misfit was evaluated before porcelain application (T1) and before (T2), and after thermomechanical cycling (T3) by stereomicroscopy. Cantilever fracture strength was tested with a 50 kN (5000 kgf) load cell at a crosshead speed of 0.5 mm/min. Qualitative and quantitative photoelastic analysis was performed to evaluate stress distribution at seven specific points in five FPDs (n = 1/group) subjected to occlusal loading. RESULTS: Only the molar showed interaction among the three factors (G × S × T; F(20.932) = 1.630; p = 0.044). Thermomechanical cycling (T2 vs. T3) had a significant effect on intra-group vertical misfit in molar, especially in LAS Co-Cr (Δ = 5.87; p = 0.018) and OP Co-Cr (Δ = 5.39; p = 0.007), with no significant effect in premolar (p > 0.05). Ceramic application combined with thermomechanical cycling (T1 vs. T3) caused a significant intra-group increase in vertical misfit in all groups, both in the molar and premolar (p < 0.05). OP Co-Cr was associated with greater vertical misfit and stress concentration. Frameworks manufactured by the CAD-CAM system exhibited lower vertical misfit and better stress distribution. FPDs with metal frameworks (>410.83 ± 72.26 N) showed significantly higher fracture strength (p < 0.05) than zirconia (277.47 ± 39.10 N), and the first signs of ceramic veneering fracture were observed around 900 N. CONCLUSIONS: FPDs with frameworks manufactured using a CAD-CAM system appear to be associated with lower vertical misfit and better stress distribution, although the section of the frameworks followed by welding may be a viable alternative. In addition, metal frameworks exhibit high fracture strength.

Effect of handling, time of use and photoactivation on the contamination of dental composite resins

This study evaluated the effect of contamination of composite resins (CRs) handled by undergraduate students during restorative procedures, varying the time (baseline, 30 days and 60 days) and experimental condition (before and after handling, contamination with saliva [positive control] and photoactivation). Eight CR tubes were randomly distributed at the dental clinic and the samples were organized into four groups: CR fragments collected before (GB) and after (GA) the restorative procedure; CR fragments contaminated with saliva (GS) and photoactivated (GP) both collected after the procedure. These 4 groups were evaluated in 3 different times: baseline (after sealing), 30 days and 60 days of use of the CR. Samples that had positive turbidity in Brain HeartInfusion (BHI) broth were sown in BHI and Sabouraud Dextrose (SB) agars for subsequent counting of Colony Forming Units (CFU mL-1). The results showed that the handling was responsible for increasing contamination (p < 0.05) at the baseline (GB [n = 0] and GA [n = 3]), as well as after 30 (GB [n = 1] and GA [n = 6]) and 60 (GB [n = 1] and GA [n = 5]) days of use. Photoactivation was responsible for the reduction for microorganisms in T0 and T60. Additionally, the time use and conservation did not influencethe contamination of CRs. Handling was responsible for the increase of contamination of CR, the photoactivation seems to reduce the number of viable microorganisms and the time of use seems not to potentiate the effect of tube contamination.

The challenge of managing oral maxillofacial rehabilitation with quality and cost-benefit.

Although orofacial cancer leads to substantial functional, esthetic, and psychosocial deficits for patients, reconstructive plastic surgeries may not be indicated for large facial defects. The high costs of prosthetic oral maxillofacial rehabilitation may hamper such treatment, which commonly involves virtual planning, craniofacial implants, and computer-aided design and computer-aided manufactured prostheses. This report shows the treatment of 2 patients with large facial defects from surgical resection of cancerous tissue who were rehabilitated with implant-supported bar-clip overdentures and facial prostheses fabricated by using low-cost straightforward methods.

Evaluation of misfit and stress distribution in implant-retained prosthesis obtained by different methods.

This study evaluated the vertical misfit, passivity, and stress distribution after tightening the screws of different prosthesis. Two implants were used to simulate the rehabilitation of partially edentulous mandible space from the second premolar to the second molar. 40 three-element screw-retained fixed dental prosthesis with distal cantilever were fabricated and divided into four groups according to the method of production of framework (n = 10): G1 = conventional casting one-piece framework, G2 = conventional casting sectioned and laser welding, G3 = conventional casting sectioned and tungsten inert gas (TIG) welding and G4 = framework obtained by CAD/CAM (computer-aided design/computer-aided manufacturing) system. The vertical misfits (both screws tightened) and the passive fit (one screw tightened) were measured under a comparator optical microscope. The data was submitted to Shapiro-Wilk test to enable comparison with ANOVA followed by Tukey with Bonferroni adjust (α = .05). The qualitative analysis of the stress distribution was performed by the photoelastic method. The vertical misfit (both screws tightened) of the G2 (24 µm) and G3 (27 µm) were significantly higher than G4 (10 µm) (p = 0,006). The passive fit (for the non-tightened) of the G1(64 µm) and G3 (61 µm) were significantly higher than the G4 (32 µm) (p=0,009). G1 showed high stress between the implants in the photoelastic analysis and G4 presented lower stress. In conclusion, CAD/CAM method results in less vertical misfit, more passivity, and consequently better stress distribution to the bone.

Evaluation of misfit and stress distribution in implant-retained prosthesis obtained by different methods

Abstract This study evaluated the vertical misfit, passivity, and stress distribution after tightening the screws of different prosthesis. Two implants were used to simulate the rehabilitation of partially edentulous mandible space from the second premolar to the second molar. 40 three-element screw-retained fixed dental prosthesis with distal cantilever were fabricated and divided into four groups according to the method of production of framework (n = 10): G1 = conventional casting one-piece framework, G2 = conventional casting sectioned and laser welding, G3 = conventional casting sectioned and tungsten inert gas (TIG) welding and G4 = framework obtained by CAD/CAM (computer-aided design/computer-aided manufacturing) system. The vertical misfits (both screws tightened) and the passive fit (one screw tightened) were measured under a comparator optical microscope. The data was submitted to Shapiro-Wilk test to enable comparison with ANOVA followed by Tukey with Bonferroni adjust (α = .05). The qualitative analysis of the stress distribution was performed by the photoelastic method. The vertical misfit (both screws tightened) of the G2 (24 μm) and G3 (27 μm) were significantly higher than G4 (10 μm) (p = 0,006). The passive fit (for the non-tightened) of the G1(64 μm) and G3 (61 μm) were significantly higher than the G4 (32 μm) (p=0,009). G1 showed high stress between the implants in the photoelastic analysis and G4 presented lower stress. In conclusion, CAD/CAM method results in less vertical misfit, more passivity, and consequently better stress distribution to the bone.

Resumo Neste estudo foi avaliado desajuste vertical, a passividade e a distribuição de tensões após o aperto dos parafusos de diferentes próteses. Dois implantes foram usados ​​para simular a reabilitação do espaço edêntulo da mandíbula do segundo pré-molar ao segundo molar. Quarenta próteses dentárias fixas parafusadas de três elementos com cantilever distal foram confeccionadas e separadas em quatro grupos de acordo com o método de obtenção da infraestrutura (n = 10): G1 = fundição convencional estrutura monobloco, G2 = fundição convencional seccionada e soldagem a laser, G3 = fundição convencional seccionada e soldagem com gás inerte de tungstênio (TIG) e G4 = infraestrutura obtida pelo sistema CAD / CAM (computer-aided design/computer-aided manufacturing). Os desajustes verticais com ambos os parafusos apertados e os desajustes relativos à avaliação de passividade com um parafuso apertado foram medidos com microscópio comparador óptico. Os dados foram submetidos ao teste de Shapiro-Wilk para comparação com ANOVA seguida de ajuste de Tukey com Bonferroni (α = 0,05). A análise qualitativa da distribuição de tensões foi realizada pelo método fotoelástico. G2 (24 μm) e G3 (27 μm) apresentaram valores significativamente maiores que G4 (10 μm) (p = 0,006) de desajuste vertical (ambos os parafusos apertados). Os valores de desajustes nos G1 (64 μm) e G3 (61 μm), do lado não apertado, foram significativamente maiores que no G4 (32 μm) (p = 0,009). G1 apresentou maior tensão entre os implantes na análise fotoelástica e G4 apresentou menor tensão. O método CAD/CAM resultou em menor desajuste, maior passividade e melhor distribuição de tensões no osso.

Whitening effect of 35% hydrogen peroxide in simulation of tooth with orthodontic bracket.

OBJECTIVE: To evaluate the color change and tooth whitening perception in 2 and 3 mm dental specimens simulating the orthodontic bracket for a 14-day period. MATERIALS AND METHODS: Forty bovine tooth fragments (8 × 7 mm) of 2 mm (G2, n = 20) and 3 mm (G3, n = 20) were divided into Control (C: without bracket simulation and whitening) and Experimental (E: with composite resin simulating orthodontic bracket cementation area). Analyses of color change (ΔE00 ) and perception of tooth whitening (WID ) were performed before (T0 ) and after (T1 ) the first bleaching session; before (T2 ) and after (T3 ) the second bleaching session; and after 7 days of the second bleaching session (T4 ). RESULTS: After 14 days (T4), ΔE00 and WID showed similarity results, except for G2C and G3E. The thickness did not influence the ΔE00 and WID (G2C = G3C and G2E = G3E). The presence of orthodontic bracket did not interfere in the color change or tooth whitening perception after 14 days, except for comparison of G2C and G3E. Additionally, dentin thickness did not influence the color change. CLINICAL SIGNIFICANCE: Teeth with orthodontic brackets showed similar color change and whitening perception to teeth without orthodontic bracket, but it is not influenced by dentin thickness.

In vitro digital image correlation analysis of the strain transferred by screw-retained fixed partial dentures supported by short and conventional implants.

PURPOSE: This study used digital image correlation (DIC) to evaluate the strain transferred by splinted and non-splinted screw-retained fixed partial dentures (FPDs) supported by short and conventional implants. MATERIAL AND METHODS: Four polyurethane models were fabricated to simulate half of the mandibular arch with acrylic resin replicas of the first premolar. Short (5 mm) and/or conventional (11 mm) implants replaced the second premolar and the first and second molars. Groups were: G1, two conventional (second premolar and first molar) and one short (second molar) implant; G2, one conventional (second premolar) and two short (first and second molar) implants; G3, three short implants; and G4, three conventional implants. Splinted (S) and non-splinted (NS) FPDs were screwed to the implant abutments. Occlusal load and a single point load on the second premolar, both of 250 N, were applied. Strain in the horizontal direction (Ɛxx) was calculated and compared using the DIC software. RESULTS: Splinted crowns presented the highest strain magnitudes of all tested groups (p < 0.05). The strain was concentrated near the short implants and presented a higher magnitude compared to conventional implants, especially in G2S (-560.13 µS), G3S (-372.97 µS), and G4S (-356.67 µS). CONCLUSIONS: Splinted crowns presented a higher strain concentration around the implants, particularly near the implant replacing the first molar. A combination of short and conventional implants seems to be a viable alternative for the rehabilitation of the posterior edentulous mandible with reduced bone height.

Photoelastic analysis of mandibular full-arch implant-supported fixed dentures made with different bar materials and manufacturing techniques.

PURPOSE: To compare the stress distribution of mandibular full dentures supported with implants according to the bar materials and manufacturing techniques using a qualitative photoelastic analysis. MATERIAL AND METHODS: An acrylic master model simulating the mandibular arch was fabricated with four Morse taper implant analogs of 4.5×6mm. Four different bars were manufactured according to different material and techniques: fiber-reinforced resin (G1, Trinia, CAD/CAM), commercially pure titanium (G2, cpTi, CAD/CAM), cobalt­chromium (G3, Co-Cr, CAD/CAM) and cobalt­chromium (G4, Co-Cr, conventional cast). Standard clinical and laboratory procedures were used by an experienced dental technician to fabricate 4 mandibular implant-supported dentures. The photoelastic model was created based on the acrylic master model. A load simulation (150N) was performed in total occlusion against the antagonist. RESULTS: Dentures with fiber-reinforced resin bar (G1) exhibited better stress distribution. Dentures with machined Co-Cr bar (G3) exhibited the worst standard of stress distribution, with an overload on the distal part of the posteriors implants, followed by dentures with cast Co-Cr bar (G4) and machined cpTi bar (G2). CONCLUSION: The fiber-reinforced resin bar exhibited an adequate stress distribution and can serve as a viable alternative for oral rehabilitation with mandibular full dentures supported with implants. Moreover, the use of the G1 group offered advantages including reduced weight and less possible overload to the implants components, leading to the preservation of the support structure.

Selective COX-2 Inhibitor (Meloxicam) and Tooth-Supporting Bone Quality. A Histomorphometric Study in Rats.

The effects of the non-steroidal anti-inflammatory drugs (NSAIDs) on bone quantity and quality were investigated for years. However, there is lack of information on the impact of NSAIDs on the quality of tooth-supporting alveolar bone in absence of periodontal inflammation. Thus, the aim of this study was to evaluate histometrically the influence of a selective COX-2 NSAID (Meloxicam) on the inter-radicular bone mineral density in rats. Forty-nine adult male Wistar rats were randomly divided into four experimental groups: Subcutaneous injection of 0.9% sterile saline for 15 days (G1; n=12) and 45 days (G2; n=11); and subcutaneous injection of Meloxicam for 15 days (G3; n=13) and 45 days (G4; n=13). Mineral density was histometrically determined in the inter-radicular area of the 1st mandibular molars and data analysis performed by two-way ANOVA (a=5%). Results showed no interaction between time and treatment (p>0.05) and that meloxicam did not affect the alveolar bone density. In contrast, it was found that inter-radicular alveolar bone density increased with time (91.88±3.08% and 92.86±2.38% for groups 15 and 45 days, respectively) (p<0.05). Within the limits of this study, daily administration of a selective COX-2 inhibitor (Meloxicam) did not affect the quality of the inter-radicular alveolar bone in absence of periodontal infection.

Selective COX-2 Inhibitor (Meloxicam) and Tooth-Supporting Bone Quality. A Histomorphometric Study in Rats

Abstract The effects of the non-steroidal anti-inflammatory drugs (NSAIDs) on bone quantity and quality were investigated for years. However, there is lack of information on the impact of NSAIDs on the quality of tooth-supporting alveolar bone in absence of periodontal inflammation. Thus, the aim of this study was to evaluate histometrically the influence of a selective COX-2 NSAID (Meloxicam) on the inter-radicular bone mineral density in rats. Forty-nine adult male Wistar rats were randomly divided into four experimental groups: Subcutaneous injection of 0.9% sterile saline for 15 days (G1; n=12) and 45 days (G2; n=11); and subcutaneous injection of Meloxicam for 15 days (G3; n=13) and 45 days (G4; n=13). Mineral density was histometrically determined in the inter-radicular area of the 1st mandibular molars and data analysis performed by two-way ANOVA (a=5%). Results showed no interaction between time and treatment (p>0.05) and that meloxicam did not affect the alveolar bone density. In contrast, it was found that inter-radicular alveolar bone density increased with time (91.88±3.08% and 92.86±2.38% for groups 15 and 45 days, respectively) (p<0.05). Within the limits of this study, daily administration of a selective COX-2 inhibitor (Meloxicam) did not affect the quality of the inter-radicular alveolar bone in absence of periodontal infection.

Resumo Os efeitos dos fármacos anti-inflamatórios não esteroidais (AINEs) sobre a quantidade e qualidade óssea tem sido investigados ao longo dos anos.Entretanto, há falta de informação sobre o impacto dos AINEs na qualidade do osso alveolar de suporte na ausência de inflamação periodontal. Assim, o objetivo deste estudo foi avaliar, histometricamente, a influência de um AINE seletivo para COX-2 (Meloxicam) na densidade mineral óssea inter-radicular em ratos. Quarenta e nove ratos Wistar, machos e adultos foram divididos aleatoriamente em quatro grupos experimentais: injeções subcutâneas de 0,9% de solução salina estéril por 15 dias (G1, n=12) e 45 dias (G2, n=11); e injeções subcutâneas de Meloxicam por 15 (G3, n=13) e 45 dias (G4, n=13). A densidade mineral foi determinada histometricamente na área inter-radicular dos primeiros molares mandibulares e a análise dos dados realizada por meio de ANOVA (a=5%). Os resultados mostraram nenhuma interação entre tempo e tratamento (p>0,05) e que o meloxicam não afetou a densidade óssea alveolar. Em contraste, foi encontrado que a densidade óssea alveolar inter-radicular aumentou ao longo do tempo (91,88±3,08% e 92,86±2,38% para os grupos 15 e 45 dias, respectivamente) (p<0,05). Dentro dos limites deste estudo, a administração diária de um inibidor seletivo para COX-2 (Meloxicam) não afetou a qualidade do osso alveolar inter-radicular na ausência de infecção periodontal.

Psychosocial aspects and temporomandibular disorders in dental students.

OBJECTIVE: Dental students have high levels of anxiety that can affect not only academic performance but also increase the risk for other diseases. It is believed that the increase in the incidence of chronic orofacial pain in temporomandibular disorders (TMDs) may have an impact on the quality of life and general health of subjects. The aim of this study was to evaluate the prevalence of TMD in dental students and its association with general health, quality of life, and anxiety. METHOD AND MATERIALS: Ninety students were evaluated by four questionnaires to determine the prevalence and sever-ity of TMD (Fonseca's questionnaire) and to quantify general health (General Health Questionnaire - GHQ), quality of life (World Health Organization Quality of Life - Brief version - WHOQOL-brief) and anxiety levels (State-Trait Anxiety Index - STAI). RESULTS: Approximately 58.9% of dental students presented TMD. Among the indicators of general health, psychologic stress (P = .010), distrust in their own performance (P = .012), and psychosomatic disorders (P = .020) showed a statistically significant difference with the presence of TMD. The four areas proposed in the questionnaire regarding quality of life, such as physical (P = .016), psychologic (P < .001), social (P = .045), and environmental (P = .017) factors also showed significant differences with the presence of TMD. CONCLUSION: A high prevalence of TMD was observed in dental students. In addition, some psychologic domains are important psychosocial indicators associated with the presence of TMDs.

Evaluation of the periodontal conditions of teeth with restored and non-restored non-carious cervical lesions.

OBJECTIVE: This research evaluated the periodontal conditions of teeth with restored and non-restored non-carious cervical lesions (NCCLs). METHOD AND MATERIALS: Thirty-seven patients presenting at least two contralateral teeth with NCCL (one restored and another non-restored) were selected. Non-restored NCCL teeth were classified as a control group, while the contralateral teeth restored within at least 3 months with a Class 5 restoration located near the gingival margin were classified as the test group. The periodontal parameters analyzed were visible plaque, probing depth, bleeding on probing, gingival recession, clinical attachment level, and width of keratinized tissue. Restorative parameters such as finishing/polishing, overhanging margins, and terminal restoration level were also examined. Statistical analysis included the comparison of periodontal and restoration parameters between groups as well as associations between these parameters. Data were statistically analyzed by the Wilcoxon, Fisher's exact, Chi-squared, and Mann-Whitney tests. The significance level was set at 5% (α < .05). RESULTS: Statistically significant differences between test and control groups were observed for visible plaque (P = .002), bleeding on probing (P = .041), and width of keratinized tissue (P = .009). Other clinical parameters such as probing depth (P = .812), gingival recession (P = .571), and clinical attachment level (P = .484), as well their associations did not show any statistically significant differences (P > .05). CONCLUSION: Restorative treatment (Class 5) of teeth with NCCL partially influenced the clinical parameters.

Tensile strength of Ni-Cr copings subjected to inner surface sandblasting using different cementing agents: An in vitro study.

OBJECTIVES: To evaluate the effect of thermal cycling and inner surface treatment with aluminum oxide at different granulations on the tensile strength of Ni-Cr copings cemented with different cementing agents. MATERIALS AND METHODS: Ninety-six metal copings were manufactured and divided into two groups: before and after thermal cycling (n = 48). The copings of both groups were internally treated by sandblasting with aluminum oxide particles of 100 (n = 24) and 320 (n = 24) mesh. The copings were cemented on previously manufactured metal cores using zinc phosphate (n = 8), conventional glass ionomer (CGIC) (n = 8) and resin-modified glass ionomer (RMGIC) (n = 8) cements. The tensile strength before and after thermal cycling was then determined (Newtons). RESULTS: The tensile strength before and after thermal cycling was significantly higher in copings cemented with RMGIC compared to CGIC (p < 0.05) and was similar to that for zinc phosphate (p > 0.05). Thermal cycling and sandblasting of the inner surface of the metal copings with different granulations did not influence retention (p > 0.05). CONCLUSIONS: Zinc phosphate cements and RMGIC showed similar retention. Additionally, the retention of the cements was not influenced by either thermal cycling or the particle size of the aluminum oxide.

Influence of Temporary Cements on the Bond Strength of Self-Adhesive Cement to the Metal Coronal Substrate

This research evaluated the influence of temporary cements (eugenol-containing [EC] or eugenol-free [EF]) on the tensile strength of Ni-Cr copings fixed with self-adhesive resin cement to the metal coronal substrate. Thirty-six temporary crowns were divided into 4 groups (n=9) according to the temporary cements: Provy, Dentsply (eugenol-containing), Temp Cem, Vigodent (eugenol-containing), RelyX Temp NE, 3M ESPE (eugenol-free) and Temp Bond NE, Kerr Corp (eugenol-free). After 24 h of temporary cementation, tensile strength tests were performed in a universal testing machine at a crosshead speed of 0.5 mm/min and 1 kN (100 kgf) load cell. Afterwards, the cast metal cores were cleaned by scraping with curettes and air jet. Thirty-six Ni-Cr copings were cemented to the cast metal cores with self-adhesive resin cement (RelyX U200, 3M ESPE). Tensile strength tests were performed again. In the temporary cementation, Temp Bond NE (12.91±2.54) and Temp Cem (12.22±2.96) presented the highest values of tensile strength and were statistically similar to each other (p>0.05). Statistically significant difference (p<0.05) was observed only between Provy (164.44±31.23) and Temp Bond NE (88.48±21.83) after cementation of Ni-Cr copings with self-adhesive resin cement. In addition, Temp Cem (120.68±48.27) and RelyX Temp NE (103.04±26.09) showed intermediate tensile strength values. In conclusion, the Provy eugenol-containing temporary cement was associated with the highest bond strength among the resin cements when Ni-Cr copings were cemented to cast metal cores. However, the eugenol cannot be considered a determining factor in increased bond strength, since the other tested cements (1 eugenol-containing and 2 eugenol-free) were similar.

Resumo Esta pesquisa avaliou a influência dos cimentos temporários (contendo eugenol [CE]ou livre de eugenol[LE]) na resistência à tração de copingsde Ni-Cr fixados com cimento resinoso auto-adesivo sobre substrato coronário metálico. Trinta e seis coroas provisórias foram divididas em 4 grupos (n=9) de acordo com os cimentos temporários: Provy, Dentsply (contendo eugenol), Temp Cem, Vigodent (contendo eugenol), RelyXTemp NE, 3M ESPE (livre de eugenol) andTemp Bond NE, KerrCorp (livre de eugenol). Após 24 h da cimentação temporária, testes de resistência à tração foram realizados em uma máquina universal de ensaios, com velocidade de 0,5 mm/min. e célula de carga de 1kN (100 kgf). Em seguida, os núcleos metálicos fundidos foram limpos por meio de raspagem com cureta ejatos de ar. Trinta e seis copings de Ni-Cr foram cimentados sobre os núcleos metálicos com cimento resinoso auto-adesivo (RelyX U200, 3M ESPE). Testes de resistência à tração foram novamente realizados. Na cimentação provisória, Temp Bond NE (12,91±2,54) e Temp Cem (12,22±2,96) apresentaram os maiores valores de resistência à tração e foram estatisticamente semelhantes entre si (p>0,05). Diferença estatisticamente significante (p<0.05) foi observada apenas entre Provy (164,44±31,23) e Temp Bond NE (88,48±21,83)após cimentação dos copingsdeNi-Cr com cimento resinoso auto-adesivo. Além disso, Temp Cem (120,68±48,27) e RelyX Temp NE (103,04±26,09) mostraram valores intermediários de resistência à tração. Em conclusão, o cimento temporário contendo eugenol, Proxy, foi associado com a mais alta resistência de união do cimento resinoso, quando os copingsde Ni-Cr foram cimentados sobre os núcleos metálicos fundidos. Entretanto, o eugenol não pode ser considerado como um fator determinante no aumento da resistência de união, já que outros cimentos testados (1 contendo eugenol e 2 livres de eugenol) foram semelhantes.

Antifungal activity of propolis against Candida species isolated from cases of chronic periodontitis.

This research evaluated the fungistatic and fungicidal activities of red propolis alcoholic extract (RPAE) against different Candida species isolated from chronic periodontitis cases, and compared with chlorhexidine (CHX). Nineteen samples of Candida species (C. albicans [n = 12], C. tropicalis [n = 5] and C. glabrata [n = 2]) isolated from chronic periodontitis cases were analyzed. The fungistatic and fungicidal activity of both RPAE and CHX were evaluated using fluconazole and C. parapsilosis (ATCC 6258) as a control. Fungistatic activity was analyzed based on the Clinical and Laboratory Standards Institute (CLSI) reference procedure to determine the minimum inhibitory concentrations. Fungicidal activity was established according to the absence of fungal growth on Sabouraud Dextrose Agar medium. The fungistatic and fungicidal activities of RPAE were observed, respectively, at 32-64 µg/mL and 64-512 µg/mL for C. albicans, 64 µg/mL and 64-256 µg/mL for C. glabrata, and 32-64 µg/mL and 64 µg/mL for C. tropicalis. CHX fungistatic activity was observed at concentrations of 0.003-1.92 µg/mL for C. albicans, 1.92 µg/mL for C. glabrata, and 0.03-1.92 µg/mL for C. tropicalis. Fluconazole fungistatic activity ranged between 1-64 µg/mL, and fungicidal activity occurred at 8-64 µg/mL, for the three Candida species analyzed. All the Candida species were susceptible to RPAE antifungal activity, but five samples of C. albicans, one of C. tropicalis and one of C. glabrata were resistant to fluconazole antifungal activity. CHX showed fungistatic activity against all the Candida species analyzed. The antifungal potential of these substances suggests that they can be applied as an alternative treatment for diseases affected by these species.

Influence of Temporary Cements on the Bond Strength of Self-Adhesive Cement to the Metal Coronal Substrate.

This research evaluated the influence of temporary cements (eugenol-containing [EC] or eugenol-free [EF]) on the tensile strength of Ni-Cr copings fixed with self-adhesive resin cement to the metal coronal substrate. Thirty-six temporary crowns were divided into 4 groups (n=9) according to the temporary cements: Provy, Dentsply (eugenol-containing), Temp Cem, Vigodent (eugenol-containing), RelyX Temp NE, 3M ESPE (eugenol-free) and Temp Bond NE, Kerr Corp (eugenol-free). After 24 h of temporary cementation, tensile strength tests were performed in a universal testing machine at a crosshead speed of 0.5 mm/min and 1 kN (100 kgf) load cell. Afterwards, the cast metal cores were cleaned by scraping with curettes and air jet. Thirty-six Ni-Cr copings were cemented to the cast metal cores with self-adhesive resin cement (RelyX U200, 3M ESPE). Tensile strength tests were performed again. In the temporary cementation, Temp Bond NE (12.91 ± 2.54) and Temp Cem (12.22 ± 2.96) presented the highest values of tensile strength and were statistically similar to each other (p>0.05). Statistically significant difference (p<0.05) was observed only between Provy (164.44 ± 31.23) and Temp Bond NE (88.48 ± 21.83) after cementation of Ni-Cr copings with self-adhesive resin cement. In addition, Temp Cem (120.68 ± 48.27) and RelyX Temp NE (103.04 ± 26.09) showed intermediate tensile strength values. In conclusion, the Provy eugenol-containing temporary cement was associated with the highest bond strength among the resin cements when Ni-Cr copings were cemented to cast metal cores. However, the eugenol cannot be considered a determining factor in increased bond strength, since the other tested cements (1 eugenol-containing and 2 eugenol-free) were similar.

Antifungal activity of propolis against Candidaspecies isolated from cases of chronic periodontitis

This research evaluated the fungistatic and fungicidal activities of red propolis alcoholic extract (RPAE) against different Candida species isolated from chronic periodontitis cases, and compared with chlorhexidine (CHX). Nineteen samples of Candida species (C. albicans [n = 12], C. tropicalis [n = 5] andC. glabrata[n = 2]) isolated from chronic periodontitis cases were analyzed. The fungistatic and fungicidal activity of both RPAE and CHX were evaluated using fluconazole and C. parapsilosis (ATCC 6258) as a control. Fungistatic activity was analyzed based on the Clinical and Laboratory Standards Institute (CLSI) reference procedure to determine the minimum inhibitory concentrations. Fungicidal activity was established according to the absence of fungal growth on Sabouraud Dextrose Agar medium. The fungistatic and fungicidal activities of RPAE were observed, respectively, at 32-64 μg/mL and 64-512 μg/mL for C.albicans, 64 μg/mL and 64-256 μg/mL for C. glabrata, and 32-64 μg/mL and 64 µg/mL for C. tropicalis. CHX fungistatic activity was observed at concentrations of 0.003-1.92 µg/mL for C. albicans, 1.92 µg/mL for C. glabrata, and 0.03-1.92 µg/mL for C. tropicalis. Fluconazole fungistatic activity ranged between 1-64 μg/mL, and fungicidal activity occurred at 8-64 μg/mL, for the threeCandida species analyzed. All the Candidaspecies were susceptible to RPAE antifungal activity, but five samples ofC.albicans, one ofC.tropicalis and one ofC.glabrata were resistant to fluconazole antifungal activity. CHX showed fungistatic activity against all the Candida species analyzed. The antifungal potential of these substances suggests that they can be applied as an alternative treatment for diseases affected by these species.

Focal epithelial hyperplasia in a Brazilian family / Hiperplasia epitelial focal em uma família brasileira

Focal Epithelial Hyperplasia (FEH) or Heck’s disease is a rare and benign condition characterized by cell proliferation in the squamous epithelium, which is manifested clinically as verrucous projections. It is associated with Human Papillomavirus (HPV) subtype 13 or 32, and it is often observed in children, young adults, and middle aged individuals, as well as some ethnic groups such as Indians and Eskimos, which suggests a possible hereditary influence. Objective: knowing that FEH is a rare disease among the Brazilian population, this article reports a case of FEH in a Brazilian family. Case report: a 27 year-old woman was assisted in the Department of Dentistry of the Federal University of Rio Grande do Norte (UFRN) showing round, plane, and well-defined lesions localized in the oral cavity, with an evolution of six years. Lesions underwent incisional biopsy, and the microscopic analysis revealed epithelial changes such as epithelium hyperplasia and prominent acanthosis. These histopathologic findings were consistent with the clinical hypothesis of FEH. Final considerations: this report reinforces the need for an accurate clinical assessment, so dentists are able to recognize, diagnose, and treat FEH in their own patients.

A hiperplasia epitelial focal (HEF) ou doença de Heck é uma doença benigna, rara e caracterizada por proliferação celular no epitélio escamoso, que se manifesta clinicamente como projeções verrucosas. É associada com o papilomavírus (HPV), subtipo humano 13 ou 32, e, muitas vezes, é observada em crianças, adultos jovens e pessoas de meia-idade, bem como em alguns grupos étnicos, como os índios e esquimós, o que sugere uma possível influência hereditária. Objetivo: sabendo que a HEF é uma doença rara na população brasileira, este artigo relata um caso de HEF em uma família brasileira. Relato de caso: paciente feminina, de 27 anos de idade, foi atendida no Departamento de Odontologia da Universidade Federal do Rio Grande do Norte (UFRN), mostrando lesões bem definidas, arredondadas, planas, localizadas em cavidade oral e com uma evolução de seis anos. As lesões foram submetidas a biópsia incisional, e a análise microscópica revelou alterações epiteliais, como hiperplasia do epitélio e acantose proeminente. Esses resultados histopatológicos foram consistentes com a hipótese clínica de HEF. Considerações finais: este relatório reforça a necessidade de uma avaliação precisa da clínica, para dentistas serem capazes de reconhecer, diagnosticar e tratar HEF em seus próprios pacientes.