Masticatory function in complete denture wearers varying degree of mandibular bone resorption and occlusion concept: canine-guided occlusion versus bilateral balanced occlusion in a cross-over trial.

PURPOSE: The present cross-over study evaluated the masticatory function and maximum occlusal force of edentulous patients with complete dentures with bilateral balanced occlusion (BBO) and canine guidance (CG), with normal (NR) and resorbed mandibular ridges (RR). METHODS: Participants received new complete dentures and both occlusal concepts (BBO and CG) were applied for a period of 30 days each. The masticatory performance was evaluated with the sieving method; masticatory ability with a visual analog scale (VAS) and maximum occlusal force was assessed by means of a gnatodynamometer. Data were analyzed using repeated-measure ANOVA or Generalized Estimating Equations (GEEs), α = 0.05. RESULTS: Thirty women completed the trial. The height of mandibular ridge was significant for the masticatory performance (ANOVA, p < 0.001, NR = 46.35 ± 12.18%, RR = 30.39 ± 9.94%), regardless of the occlusion guidance. A significant effect of the occlusion guidance was observed for the maximum occlusal force (ANOVA, p = 0.021, CG = 31.99 ± 12.74 N, BBO = 28.37 ± 9.83 N). The occlusion guidance was not significant for the masticatory performance (ANOVA, p = 0.156) and the height of the mandibular ridge did not influence on the occlusal force (ANOVA, p = 0.060). The interaction of the factors (guidance × ridge) was not significant for masticatory performance (ANOVA, p = 0.184) and occlusal force (ANOVA, p = 0.236). The VAS scores showed a significant effect of the ridge on chewing of lettuce, resulting in greater ease (GEEs, p = 0.016) and chewing quality (GEE, p = 0.028) of this food for participants with resorbed ridges. Participants with CG reported greater ease of chewing fresh bread and beef, and expressed higher quality of chew raw carrot. Participants with CG and normal ridges exhibited the highest overall chewing ability, in comparison to BBO (Bonferroni, p < 0.05, CG = 91.9, BBO = 72.7). CONCLUSIONS: CG represents a viable alternative to the BBO in complete dentures with satisfactory clinical results related to the self-perception of chewing and occlusal force.

A Randomized Clinical Trial of Oral Health-Related Quality of Life, Peri-Implant and Kinesiograph Parameters in Wearers of One-or Two-Implant Mandibular Overdentures.

PURPOSE: The present randomized clinical trial compared the oral health-related quality of life (OHRQoL), peri-implant parameters, mandible movements, and maxillary complete denture movement during chewing between wearers of single- (1-IOD) and wearers of two-implant overdentures (2-IODs) for a period of 12 months. MATERIALS AND METHODS: Twenty-one complete denture wearers were randomly allocated into two parallel groups: 1-IOD (n = 11) or 2-IODs (n = 10). The validated Brazilian version of the OHIP-EDENT was used to evaluate the OHRQoL. A kinesiograph recorded maxillary complete denture movement during chewing of hard food testing (polysulphide impression material) and soft food testing (bread). Peri-implant parameters were also recorded: plaque index (PI), bleeding on probing (BOP), and probing depth (PD). The Friedman test was used to compare the OHRQoL data and peri-implant parameters among periods; the Mann-Whitney test was performed to compare the groups (1- and 2-IODs). One-way ANOVA and the Bonferroni test were used to compare mandible movement during chewing among periods, and the t-test for independent samples was used to compare the groups. Maxillary complete denture movement was analyzed using three-way ANOVA followed by the Bonferroni test. All statistical analyses were performed at α = 0.05. RESULTS: Both treatments led to better general OHRQoL in comparison to conventional complete dentures (p < 0.001). Better OHRQoL was observed among 2-IOD patients at the 12-month follow up (p = 0.034). Peri-implant parameters were similar irrespective of the group and follow-up period. Vertical opening was significantly higher among 1-IOD patients at 3 months (p = 0.038). Decreased maxillary denture vertical intrusions were observed with complete dentures in comparison with overdentures (p = 0.006), regardless of the food test (p = 0.251); however, vertical intrusion was significantly higher among 1-IOD patients (p = 0.043). CONCLUSIONS: This study suggested that 1-IOD can improve patient OHRQoL and may be similar to 2-IODs in preservation of both peri-implant parameters and masticatory movements.

Retention Force and Wear Characteristics of three Attachment Systems after Dislodging Cycles.

Several attachment systems for mandibular implant-supported overdentures are currently available and studies are required to understand their mechanical properties. The objective of this study was to evaluate the retention force and wear characteristics of three attachment systems in a simulation of the cyclic dislodging of implant-supported overdentures. Thirty samples were fabricated and divided into 3 groups: 1-O-ring; 2-Mini Ball; and 3-Equator. A mechanical fatigue test was applied to the specimens using a servo-hydraulic universal testing machine performing 5500 insertion/removal cycles (f=0.8 Hz), immersed in artificial saliva. Retention force values ​​were obtained before and after 1500, 3000, and 5500 cycles using a speed of 1 mm/min and a load cell of 1 kN. One specimen from each group was randomly selected and analyzed by scanning electron microscopy. Two-way repeated measures ANOVA and the Bonferroni post hoc test were used for statistical analyses (α=0.05). The O-ring system remained stable during all periods tested and exhibited significantly lower retention force values than the Mini Ball and Equator systems. The Mini Ball system exhibited a significant increase in retention force after the mechanical test (baseline=21.04±3.29N; 5500 cycles=24.01±3.30N).The Equator system exhibited a significant decrease in retention force after each period tested, but the values were higher than the other systems. The type of attachment was found to influence retention force in different ways after mechanical tests. The Equator system exhibited the highest retention force values. The Mini Ball and Equator matrices produced deformation and wear on the surfaces without breakage of the polyamide rings.

Retention force and wear characteristics of three attachment systems after dislodging cycles

Abstract Several attachment systems for mandibular implant-supported overdentures are currently available and studies are required to understand their mechanical properties. The objective of this study was to evaluate the retention force and wear characteristics of three attachment systems in a simulation of the cyclic dislodging of implant-supported overdentures. Thirty samples were fabricated and divided into 3 groups: 1-O-ring; 2-Mini Ball; and 3-Equator. A mechanical fatigue test was applied to the specimens using a servo-hydraulic universal testing machine performing 5500 insertion/removal cycles (f=0.8 Hz), immersed in artificial saliva. Retention force values ​​were obtained before and after 1500, 3000, and 5500 cycles using a speed of 1 mm/min and a load cell of 1 kN. One specimen from each group was randomly selected and analyzed by scanning electron microscopy. Two-way repeated measures ANOVA and the Bonferroni post hoc test were used for statistical analyses (α=0.05). The O-ring system remained stable during all periods tested and exhibited significantly lower retention force values than the Mini Ball and Equator systems. The Mini Ball system exhibited a significant increase in retention force after the mechanical test (baseline=21.04±3.29N; 5500 cycles=24.01±3.30N).The Equator system exhibited a significant decrease in retention force after each period tested, but the values were higher than the other systems. The type of attachment was found to influence retention force in different ways after mechanical tests. The Equator system exhibited the highest retention force values. The Mini Ball and Equator matrices produced deformation and wear on the surfaces without breakage of the polyamide rings.

Resumo Vários sistemas de encaixe para sobredentaduras mandibulares implantossuportadas estão atualmente disponíveis e estudos são necessários para entender as suas propriedades mecânicas. O objetivo deste estudo foi avaliar a força de retenção e as características de desgaste de três sistemas de encaixe por meio de uma simulação de deslocamento cíclico de sobredentaduras implantossuportadas. Trinta amostras foram fabricadas e divididas em 3 grupos: 1-O-ring; 2-Mini Ball; e 3-Equador. Um teste de fadiga mecânica foi aplicado aos espécimes utilizando uma máquina de teste universal servo-hidráulica com 5500 ciclos de inserção/remoção (f = 0,8 Hz), imersos em saliva artificial. Os valores da força de retenção foram obtidos antes e após 1500, 3000 e 5500 ciclos utilizando uma velocidade de 1 mm/min e uma célula de carga de 1 kN. Um espécime de cada grupo foi selecionado aleatoriamente e analisado por microscopia eletrônica de varredura. O teste de Análise de Variância a dois fatores para medidas repetidas e o teste de comparações múltiplas de Bonferroni foram utilizados para análises estatísticas (α = 0,05). O sistema de O-ring permaneceu estável durante todos os períodos testados e apresentou valores de força de retenção significativamente menores do que os sistemas Mini Ball e Equator. O sistema Mini Ball apresentou um aumento significativo na força de retenção após o teste mecânico (controle = 21,04 ± 3,29N; 5500 ciclos = 24,01 ± 3,30N). O sistema Equator apresentou uma diminuição significativa na força de retenção após cada período testado, mas os valores eram maiores do que os outros sistemas. O tipo de sistema de encaixe influenciou na força de retenção de diferentes maneiras após testes mecânicos. O sistema do Equador exibiu os maiores valores de força de retenção. As matrizes dos sistemas Mini Ball e Equator produziram deformação e desgaste nas superfícies sem ruptura dos anéis de poliamida.

Implant-supported double-bar overdenture to reestablish lip support in an atrophic maxilla: a case report.

Prosthodontic treatment for edentulous maxillae with severe bone loss is a challenge to clinicians. Although implant-supported, fixed maxillary complete dentures are increasingly common, they are not always able to provide adequate lip support without a buccal overextension in patients with bone loss. The overextended buccal flange makes it difficult for patients to clean under the prosthesis. This case report describes rehabilitation of an atrophic maxilla through an implant-supported double-bar overdenture designed to resolve difficulties in oral hygiene maintenance that were caused by the buccal overextension of the prosthetic flange in a previous implant-supported fixed complete denture. In addition to reestablishing lip support, overdentures with a double-bar system provide retention and stability, because the prosthesis is only removed for cleaning by the patient with the help of a specific key. Implant-supported double-bar overdentures represent a viable and versatile option for rehabilitation of atrophic maxillae.

Influence of the use of complete denture adhesives on microbial adhesion and biofilm formation by single- and mixed-species.

OBJECTIVES: To verify whether the Ultra Corega Cream and Corega Strip Denture Adhesive adhesives interfere in the microbial adhesion and biofilm formation by Candida albicans and Lactobacillus casei in single- and mixed-species settings, and observe whether synergistic or antagonistic relationships between these species occur. METHODS: Specimens made from heat-polymerized acrylic resin (Lucitone 550) were fabricated (n = 144) with a circular shape and standardized roughness (3.0 µm ±0.3 Ra) and were divided into three groups: Without Adhesive (WA), with Ultra Corega Cream adhesive (CA) and Corega Strips adhesive (SA). These groups were divided into three subgroups each: C. albicans single-species, L. casei single-species and C. albicans with L. casei (mixed-species). Microbial adhesion and biofilm formation assays were performed in duplicate at four distinct experimental times (n = 8 per experimental condition). The amount of each microorganism on the surfaces of the specimens was observed by counting of the Colony Forming Units (CFU) per substrate. Additional specimens were characterized by Scanning Electron Microscopy (SEM), with 18 specimens being used in this analysis (n = 18), 2 per experimental condition (n = 2). Two-way ANOVA and Tukey's test for multiple comparisons were employed, using α≤0.05. RESULTS: L. casei (mixed-species) adhered more on the WA substrate than the CA, while C. albicans (single- and mixed-species) adhered more on the SA. C. albicans, both single- and mixed-species adhered more than the L. casei (single- and mixed-species), regardless of the substrate. L. casei (single-species) formed more biofilm on the WA, but in its mixed cultivation, it had no difference of growth among the tested situations. C. albicans (single- and mixed-species) formed more biofilm on the SA than the CA, and the fungus formed more biofilm when compared to L. casei. In general, whenever a species was compared in its single- and mixed-species situation, no statistically significant difference was observed. SEM of biofilm formation assays demonstrated that L. casei single-species WA formed more biofilm than when the adhesives tested were used, and C. albicans (both single- and mixed-species) formed more biofilm on the SA than on the CA. CONCLUSIONS: (1) The two denture adhesives tested increased the adhesion of C. albicans but not of L. casei; (2) biofilm formation by C. albicans (single- and mixed-species) was increased on the SA; (3) Relations of synergism or antagonism was not observed between the two microorganisms studied.

One-year prospective clinical study comparing patient satisfaction and masticatory performance of mandibular overdentures supported by one versus two implants.

OBJECTIVE: There is a lack of clinical evidence on mandibular overdentures (MOD) supported by a single implant. To compare patient satisfaction and masticatory performance in MOD supported by one versus two implants in a two-group parallel randomized clinical trial. MATERIAL AND METHODS: Twenty-one patients wearing new maxillary and mandibular complete dentures (CDs) were randomly divided to receive one (GI, n = 11) or two (GII, n = 10) implants in the mandibular arch. Four months after implant placement, o-ring abutments were installed in the implants, and matrix attachments were placed in the lower complete dentures. Patient satisfaction with their dentures and masticatory performance were compared at baseline, 3, 6, and 12 months after the procedure. Data on patient satisfaction were analyzed using the Friedman test and the Mann-Whitney U test. Data on masticatory performance were analyzed using one-way repeated measures analysis of variance (ANOVA) and Student's t test (α=0.05). RESULTS: Both groups exhibited a significant increase in overall patient satisfaction in all periods evaluated (p<0.05), except for GI after 12 months, which had values similar to baseline (p=0.74). Satisfaction levels of GI and GII were similar at baseline, 3 and 6 months, but GII showed higher satisfaction levels (p=0.01) than GI at 12 months. GI and GII exhibited a significant increase (p<0.05) in masticatory performance for all periods relative to baseline. However, GII had higher masticatory performance with dentures than GI, regardless of the period (p<0.05). CONCLUSION: MOD supported by two implants demonstrated better patient satisfaction in the follow-up at 12 months and better masticatory performance than MOD supported by one implant.

Proinflammatory cytokine production from NOK-SI keratinocytes after exposure to denture adhesives.

STATEMENT OF PROBLEM: Although the cytotoxicity of denture adhesives has been widely assessed, data on the release of proinflammatory cytokines from oral epithelial cells are still scarce. PURPOSE: The purpose of this in vitro study was to evaluate the proinflammatory cytokines interleukin (IL) 1ß, IL-6, and tumor necrosis factor α (TNF-α) released from human oral keratinocytes after exposure to denture adhesives. MATERIAL AND METHODS: Eluates of the Ultra Corega cream, Corega powder Fixador Ultra, and Corega strip denture adhesives were created at 1% wt/vol after 24 hours of exposure in a Dulbecco modified Eagle medium culture. The release of IL-1ß, IL-6, and TNF-α was measured using a sandwich enzyme-linked immunosorbent assay after the oral epithelial cells (NOK-SI) had been exposed to the eluates for 3, 6, and 24 hours (n=6). RESULTS: IL-1ß release from the strip was higher at 3 hours compared with the control (Bonferroni post hoc test, P=.016). IL-6 releases from the cream and powder denture adhesives at 6 and 24 hours were higher than for the controls (Bonferroni post hoc test, P<.05). TNF-α release was not detectable in some groups and periods. CONCLUSIONS: In long periods, denture adhesive strips do not induce any change on cytokine release from human oral keratinocytes.

Free Gingival Graft to Increase Keratinized Mucosa after Placing of Mandibular Fixed Implant-Supported Prosthesis.

Insufficiently keratinized tissue can be increased surgically by free gingival grafting. The presence or reconstruction of keratinized mucosa around the implant can facilitate restorative procedure and allow the maintenance of an oral hygiene routine without irritation or discomfort to the patient. The aim of this clinical case report is to describe an oral rehabilitation procedure of an edentulous patient with absence of keratinized mucosa in the interforaminal area, using a free gingival graft associated with a mandibular fixed implant-supported prosthesis. The treatment included the manufacturing of a maxillary complete denture and a mandibular fixed implant-supported prosthesis followed by a free gingival graft to increase the width of the mandibular keratinized mucosa. Free gingival graft was obtained from the palate and grafted on the buccal side of interforaminal area. The follow-up of 02 and 12 months after mucogingival surgery showed that the free gingival graft promoted peri-implant health, hygiene, and patient comfort. Clinical Significance. The free gingival graft is an effective treatment in increasing the width of mandibular keratinized mucosa on the buccal side of the interforaminal area and provided an improvement in maintaining the health of peri-implant tissues which allows for better oral hygiene.

Evaluation of methods for stain removal in acrylic resin denture teeth: in vitro study / Avaliação de métodos de remoção de manchas em dentes de resina acrílica para prótese total: estudo in vitro

Introduction: The staining of artificial teeth can be related to the acrylic resin abrasion caused by brushing, resulting in higher deposition of dyes from the beverage, and consequently higher aesthetic damage. Objective: The aim of this in vitro study was to evaluate methods for removal of stains from acrylic denture teeth using spectrophotometric analysis. Material and method: Artificial teeth were divided into twelve groups (n=10) according to the type of treatment (re-polishing - Re or immersion in Corega Tabs - Sp), staining solutions, coffee (Cf) and Coca-Cola® (Cc) or water (W) and with/without toothbrushing (B). The Sp specimens were submitted to seven immersion cycles (5 min each). The Re specimens were polished with pumice stone followed by Spain white paste. Color differences (ΔE) were captured by a spectrophotometer: T0 (baseline), T1 (after brushing/immersion in solutions) and T2 (after Re or Sp). Result: Statistically significant color change between T1 and T2 (paired T-test; α =.05) was observed for the group CfSp (p=.032); and for the groups BWRe (p=.000), BCfRe (p=.049) and CcRe (p=.042). Higher color changes were observed for the specimens submitted to toothbrushing (ANOVA two way; p<.001). Conclusion: It could be concluded that the immersion in sodium perborate (Corega Tabs) can be used for removal of coffee stains from denture teeth, and re-polishing for removal of Coca-Cola® stains. Still, toothbrushing produced greater color changes on denture teeth, regardless of the immersion solution.

Introdução: O manchamento dos dentes artificiais pode estar relacionado à abrasão da resina acrílica provocada pela escovação, resultando na maior deposição de corantes provenientes de bebidas, e consequentemente maior prejuízo estético. Objetivo: O objetivo do presente estudo foi avaliar métodos de remoção de manchas extrínsecas por meio de analise com espectofotômetro. Material e método: Dentes artificiais foram divididos em 12 grupos (n=10), de acordo com o tipo de tratamento (repolimento – Re ou imersão em perborato de sódio, Corega Tabs – Sp), tipo de solução de manchamento, café (Cf) ou Coca-Cola® (Cc) ou água (W) e com/sem escovação (B). Os métodos de remoção de manchas propostos (Re e Sp) foram realizados de acordo com protocolos pré-estabelecidos. Os espécimes Sp foram submetidos a 7 ciclos de imersão (5 minutos cada). O repolimento foi realizado com pastas de pedra pomes e branco de espanha, utilizando escovas de cerdas macias e rodas de feltro. As leituras de estabilidade de cor (ΔE) foram realizadas por meio de um espectrofotômetro: T0 (baseline), T1 (após escovação/imersão em bebidas), e T2 (após Re ou Sp). Resultado: Alterações de cor entre T1 e T2 (teste T pareado; α=0,05) foram observadas para o grupo CfSp (p=.032); e para os grupos BWRe (p=.000), BCfRe (p=.049) e CcRe (p=.042). Os dentes artificiais submetidos à escovação mostraram maior alteração de cor (ANOVA 2 fatores; p<0,001). Conclusão: Conclui-se que a imersão em perborato de sódio (Corega Tabs) pode ser utilizada para remoção de manchas de café e o repolimento para remoção de manchas de Coca-Cola®. Ainda, a escovação produziu as maiores alterações de cor nos dentes artificiais, independentemente da solução de imersão.

Mandibular kinesiographic pattern of women with chronic TMD after management with educational and self-care therapies: A double-blind, randomized clinical trial.

STATEMENT OF PROBLEM: Limited mandibular movements are one of the most important signs of temporomandibular disorders (TMDs) and may cause functional difficulties. PURPOSE: The purpose of this double-blind, randomized clinical trial was to evaluate the effect of treatment with only educational or education associated with self-care therapies on the pattern of mandibular movements of women with chronic painful TMDs. MATERIAL AND METHODS: Forty-two women were selected and randomly divided into 3 groups, control group (CG, n=13), education group (EG, n=16), and education and self-care group (ESG, n=13), according to the sequence of treatment they received. A kinesiograph device recorded mandibular movements during maximum mouth opening and mastication at baseline (T0) and at 30-day (T1) and 60-day (T2) follow-up. Kinesiographic data were statistically analyzed using 1-way ANOVA, followed by the Bonferroni test for multiple comparisons of means (α=.05). RESULTS: The ESG group demonstrated an improvement in the maximum vertical opening (MVO= 5.1 ±3.4 mm; P=.012) and anteroposterior mandibular movement (MAM) during maximum opening (7.4 ±9.5; P=.019), significantly higher than that of the EG (MVO=1.8 ±3.5 mm; MAM=0.8 ±5.0 mm) and the CG (MVO=0.9 ±3.8 mm; MAM=0.8 ±4.4 mm) after 30 days of follow-up. Moreover, at T1, vertical mandibular movement during mastication was significantly higher in the ESG group (17.4 ±1.7 mm) than in the EG group (15.0 ±2.8, P=.027). No significant differences were found between the women who received treatment with educational and self-care therapies for 60 days and the women who received this treatment for 30 days. CONCLUSIONS: In the short-term, education and self-care treatment positively influenced the mandibular movement pattern of women with chronic painful TMDs.

In Vitro Assessment of the Abrasion Resistance of Two Types of Artificial Teeth Submitted to Brushing.

PURPOSE: To assess the effect of brushing with different solutions on the abrasion resistance of two types of acrylic resin teeth. MATERIALS AND METHODS: Maxillary premolars from two types of acrylic teeth (Biotone and Biotone IPN) were divided into six groups (n = 12), according to the solution used during brushing: distilled water (control), coconut soap, or dentifrice. A mechanical brushing machine was used to simulate approximately 1 year of brushing (11,000 strokes). The weight loss (WL) of teeth was obtained from the difference between the initial (IW) and final weight (FW) of each specimen, and the mean of percentage of weight loss (PWL) was calculated for each group. Data were analyzed using the Kruskal-Wallis test, followed by Bonferroni's post-test comparison (α = 0.05). RESULTS: A statistically significant difference was found for the factor solution (p < 0.001). Brushing using dentifrice caused the highest values of weight loss (-0.50%), in comparison with the groups brushed with coconut soap (0.00%) or distilled water (0.00%). CONCLUSIONS: For both types of artificial teeth, brushing with dentifrice produced higher abrasion than brushing with coconut soap or water.

Crossover clinical trial of different methods of removing a denture adhesive and the influence on the oral microbiota.

STATEMENT OF PROBLEM: The difficulty of removing denture adhesive is a common problem reported by users of these products. PURPOSE: The purpose of this clinical study was to investigate the effectiveness of different cleaning protocols for removing a denture adhesive (DA) and the influence on the oral microbiota. MATERIAL AND METHODS: Twenty participants wearing well-fitting complete dentures were instructed to use a denture adhesive 3 times a day during a 4-week trial, divided into 4 stages: (A) control-3 daily denture brushings using water at ambient temperature, (B)-3 daily denture brushings using water at ambient temperature plus coconut soap, (C)-3 daily denture brushings using water at ambient temperature plus dentifrice; (D)-3 daily denture brushings using water at ambient temperature combined with immersion in sodium perborate solution for 5 minutes before nocturnal sleep. After each 1-week stage, saliva specimens were collected. A dye was used to display and quantify the remaining DA on the internal surface of the maxillary dentures as a percentage. For microbiological analysis, the saliva was diluted and plated onto Petri dishes containing a nonselective culture medium and Candida spp culture media. After the incubation period, Candida species were identified and the number of colony forming units (CFU/mL) was calculated. RESULTS: A significant difference was found among the 4 cleaning methods for the quantification of remaining DA (Friedman, P=.036). Brushing the dentures with coconut soap, dentifrice, or water combined with immersion in sodium perborate solution was more effective in removing DA than brushing with only water. The cleaning methods did not influence the quantification of microorganisms in general or Candida albicans and other Candida species in particular. CONCLUSIONS: Brushing the dentures with coconut soap, dentifrice, or water combined with immersion in sodium perborate solution was more effective for removing cream-type denture adhesive than brushing with only water.

Bond Strength of Artificial Teeth Attached to a Microwave-Polymerized Denture Base Resin after Immersion in Disinfectant Solutions.

PURPOSE: To evaluate the bond strength between two types of acrylic resin teeth and a microwave denture base resin after immersion in disinfectant solutions for 180 days. MATERIALS AND METHODS: Eighty specimens made of acrylic resin teeth (Biotone and Biotone IPN) attached to a microwave polymerized denture base resin (Nature-Cryl MC) were divided into eight groups (n = 10) according to the treatment (distilled water-control, 2% chlorhexidine digluconate, 1% sodium hypochlorite and sodium perborate solution-Corega Tabs). The shear strength tests (MPa) were carried out using a universal testing machine with a 0.5 mm/min speed. Data analysis was performed using ANOVA and multiple comparison Student-Newman-Keuls post hoc test (α = 0.05). RESULTS: Biotone IPN showed similar results among the groups (distilled water, 8.25 ± 1.81 MPa; chlorhexidine, 7.81 ± 3.34 MPa; hypochlorite, 7.75 ± 3.72 MPa; and Corega Tabs, 7.58 ± 2.27 MPa, whereas Biotone showed significantly lower shear bond strength values for the groups immersed in Corega Tabs (5.25 ± 3.27 MPa) and chlorhexidine (6.08 ± 2.35 MPa). CONCLUSIONS: Soaking the dentures in 1% sodium hypochlorite could be recommended as a disinfectant solution for dentures fabricated with conventional acrylic resin denture teeth and microwave denture base resin. For dentures fabricated with IPN teeth and microwave denture base resin, all the soaking solutions evaluated in this study could be suggested to denture wearers.

Reestablishment of Occlusal Vertical Dimension in Complete Denture Wearing in Two Stages.

The assessment and reestablishment of the occlusal vertical dimension (OVD) are considered important factors in the treatment of complete denture wearers. The long-time use of a complete denture can result in jaw displacement due to abrasion of the artificial teeth and residual ridge resorption, causing esthetic complications. Most patients with old dentures and incorrect OVD accept reestablishment of the OVD with new complete dentures, even if they were used to their old dentures. The present clinical report describes a method of gradual reestablishment of OVD using a diagnostic acrylic splint on artificial teeth in old complete dentures before the manufacture of new complete dentures. Clinical Significance. The use of a reversible treatment for reestablishment of the OVD in old complete dentures with a diagnostic occlusal acrylic splint allows for the reestablishment of the intermaxillary relationship, providing physiological conditions of masticatory performance associated with the recovery of facial esthetics in edentulous patients.

Antimicrobial activity of a tissue conditioner combined with a biocide polymer.

BACKGROUND: The characteristics of tissue conditioners support microorganism development that can threaten the health of the dentures user. PURPOSE: The object of this study was to evaluate the effect on antimicrobial activity, roughness and wettability surface of a tissue conditioners material combined with the antimicrobial polymer poly (2-tert-butilaminoethyl) methacrylate (PTBAEMA). MATERIALS AND METHODS: Specimens of tissue conditioner (Coe Soft(®)) were divided into three groups, according to the concentration of PTBAEMA incorporated (0, 10 and 25%). Antimicrobial activity was assessed by adherence assay of one of the microorganisms, Staphylococcus aureus, Streptococcus mutans and Candida albicans. Roughness measurements were made using a Mitutoyo SJ-400, and the mean arithmetic roughness values (Ra) obtained were used for the comparisons. The wettability properties were determined by contact angle measurements. RESULTS: The group containing 25% of PTBAEMA inhibited totally the S. aureus and S. mutans biofilm formation. A significant reduc tion in the S. aureus (Kruskal-Wallis, p = 0,001) and S. mutans (Kruscal-Wallis, p = 0,001) count for 10% PTBAEMA group compared with respective control group. No significant difference was found for C. albicans among PTBAEMA groups and control group (ANOVA, p > 0,05). Incorporating 10 and 25% PTBAEMA increased surface roughness and decreased contact angles (ANOVA and Tukey's post hoc tests, α = 5%). CONCLUSION: Incorporating 10% PTBAEMA into tissue conditioner increases wettability and roughness of tissue conditioner surface; and decreases the adhesion of S. mutans and S. aureus on material surface, but did not exhibit antimicrobial effect against C. albicans. SIGNIFICANCE: The PTBAEMA incorporated into tissue conditioner could prevent biofilm formation on elderly patient.

Split-Framework in Mandibular Implant-Supported Prosthesis.

During oral rehabilitation of an edentulous patient with an implant-supported prosthesis, mandibular flexure must be considered an important biomechanical factor when planning the metal framework design, especially if implants are installed posterior to the interforaminal region. When an edentulous mandible is restored with a fixed implant-supported prosthesis connected by a fixed full-arch framework, mandibular flexure may cause needless stress in the overall restorative system and lead to screw loosening, poor fit of prosthesis, loss of the posterior implant, and patient's discomfort due to deformation properties of the mandible during functional movements. The use of a split-framework could decrease the stress with a precise and passive fit on the implants and restore a more natural functional condition of the mandible, helping in the longevity of the prosthesis. Therefore, the present clinical report describes the oral rehabilitation of an edentulous patient by a mandibular fixed implant-supported prosthesis with a split-framework to compensate for mandibular flexure. Clinical Significance. The present clinical report shows that the use of a split-framework reduced the risk of loss of the posterior implants or screws loosening with acceptable patient comfort over the period of a year. The split-framework might have compensated for the mandibular flexure during functional activities.

Effect of a denture adhesive on the satisfaction and kinesiographic parameters of complete denture wearers: a cross-over randomized clinical trial.

The aim of the present study was to assess the effect of a denture adhesive (DA) on patient satisfaction and kinesiographic parameters of complete denture wearers by a cross-over study. Fifty edentulous patients received a set of new complete dentures. After an adaptation period, the participants were enrolled in the trial and randomized to receive a sequence of treatment protocols: Protocol 1- DA use during the first 15 days, followed by no DA for the next 15 days; Protocol 2- no DA during the first 15 days, followed by use of DA for the next 15 days. Outcomes were assessed after 15 days of each sequence of treatment. A questionnaire was used to assess the patients' satisfaction. A kinesiograph was used to record mandible movements and patterns of maxillary complete denture movement during chewing. The Wilcoxon test (α=0.05) and a paired sample t-test (α=0.05) were used to compare satisfaction levels and kinesiographic data, respectively. Use of DA improved the overall level of patient satisfaction (p<0.001). The kinesiographic recordings revealed a significant increase (1.7 mm) in vertical mandible movements (p<0.001) during chewing and a lower (0.3 mm) vertical intrusion of the maxillary complete dentures (p=0.002) during chewing after using the DA. Use of DA in complete denture wearers improved the patients' satisfaction and altered mandible movements, with increases in vertical movements during chewing and less intrusion of maxillary complete dentures.

Impact of replacing conventional complete dentures with implant-supported fixed complete dentures.

The aim of this study was to assess the impact of replacing conventional mandibular complete dentures with implant-supported fixed complete dentures (ISFDs) on the oral health-related quality of life (OHQOL) of edentulous patients and on the associated kinesiographic parameters. The patients had their complete dentures replaced by ISFDs and were assessed after 1, 2, 3, 6, and 12 months. An improvement of general OHQOL was observed 2 months after treatment with ISFDs. Kinesiographic recordings revealed significant mandibular vertical and horizontal opening increases and a greater vertical intrusion of the maxillary complete dentures during clenching after the treatment with ISFD.

Effect of a Denture Adhesive on the Satisfaction and Kinesiographic Parameters of Complete Denture Wearers: A Cross-Over Randomized Clinical Trial

The aim of the present study was to assess the effect of a denture adhesive (DA) on patient satisfaction and kinesiographic parameters of complete denture wearers by a cross-over study. Fifty edentulous patients received a set of new complete dentures. After an adaptation period, the participants were enrolled in the trial and randomized to receive a sequence of treatment protocols: Protocol 1- DA use during the first 15 days, followed by no DA for the next 15 days; Protocol 2- no DA during the first 15 days, followed by use of DA for the next 15 days. Outcomes were assessed after 15 days of each sequence of treatment. A questionnaire was used to assess the patients´ satisfaction. A kinesiograph was used to record mandible movements and patterns of maxillary complete denture movement during chewing. The Wilcoxon test (α=0.05) and a paired sample t-test (α=0.05) were used to compare satisfaction levels and kinesiographic data, respectively. Use of DA improved the overall level of patient satisfaction (p<0.001). The kinesiographic recordings revealed a significant increase (1.7 mm) in vertical mandible movements (p<0.001) during chewing and a lower (0.3 mm) vertical intrusion of the maxillary complete dentures (p=0.002) during chewing after using the DA. Use of DA in complete denture wearers improved the patients´ satisfaction and altered mandible movements, with increases in vertical movements during chewing and less intrusion of maxillary complete dentures.

O objetivo deste estudo foi avaliar o efeito da utilização de um adesivo para prótese na satisfação e nos parâmetros cinesiográficos em usuários de próteses totais por meio de um estudo "cross-over". Cinquenta pacientes desdentados receberam novas próteses totais bimaxilares. Após um período de adaptação, os participantes incluídos no estudo receberam uma sequência de tratamento: Protocolo 1- utilização do adesivo para prótese durante os primeiros 15 dias, seguida por não utilização do adesivo os próximos 15 dias; Protocolo 2- não utilização do adesivo durante os primeiros 15 dias; seguida por utilização do adesivo nos próximos 15 dias. Os resultados foram avaliados após 15 dias de cada sequência de tratamento. Um questionário para avaliar a satisfação dos pacientes e um cinesiógrafo para registrar os movimentos mandibulares e o padrão de movimento da prótese total maxilar durante mastigação foram utilizados. O teste de "Wilcoxon" (α=0,05) e o "t-test" de Student para amostras pareadas (α=0,05) foram utilizados para comparar o grau de satisfação dos pacientes e os dados cinesiográficos, respectivamente. O adesivo para prótese melhorou significativamente a satisfação geral dos participantes (p<0,001). Os registros cinesiográficos mostraram um aumento significativo (1,7 mm) no movimento mandibular vertical (p<0,001) e uma menor intrusão (0,3 mm) da prótese total superior (p=0,002) durante a mastigação após o uso de adesivo. O uso de adesivo para prótese melhorou a satisfação dos usuários de próteses totais e gerou um aumento no movimento mandibular vertical e uma menor intrusão da prótese total maxilar durante a mastigação.