Application of Soft Relining Materials in Dental Medicine - Clinical Results.

AIM: The objective of this study was to carry out an in vivo investigation of patients wearing dentures relined with soft materials, assuming their positive and negative alterations in time. MATERIALS AND METHODS: A direct survey method was used to gather data from 23 patients included in this study (11 male and 12 female patients). Twenty-seven dentures were made (12 partial and 15 total dentures) 9 of which in chairside procedures, 11 - in a laboratory, and 7 were made using the direct-indirect method. Patients were included in regular follow-ups at one month and six months, and at one, two, and three years after dentures delivery. The study started in 2014 and continued till 2017. RESULTS AND DISCUSSION: All participants completed questionnaires which included questions related to changes in retention and stability of the relined dentures, changes in color and softness, in bond strength, and inflammation. CONCLUSION: There were no significant differences in the behavior of the different groups of materials at six months. After six months we observed decline in the bond strength of the vinyl-polysiloxane (VPS) materials, as well as increased staining and hardness in the poly-methyl-methacrylate (PMMA).

A combination technique for relining removable prostheses.

The two major types of resilient lining material include acrylic based lining material and silicone based lining material. Both these materials have few inherent disadvantages associated with them. A technique for overcoming the disadvantages of both the acrylic and silicone based lining materials by using them in a combination is presented in this article.

Effect of incorporating antifungals on the water sorption and solubility of interim resilient liners for denture base relining.

STATEMENT OF PROBLEM: Incorporating antifungals into interim denture resilient liners has been proposed to prolong their clinical longevity and to treat denture stomatitis. However, information is lacking on the effect of this addition on water sorption and solubility. PURPOSE: The purpose of this in vitro study was to evaluate the addition of minimum inhibitory concentrations (MICs) of antifungals for Candida albicans biofilm on the water sorption (WS) and solubility of interim denture resilient liners. MATERIAL AND METHODS: Disk-shaped specimens (n=10; 50×0.5 mm) of tissue conditioner (Softone) and resilient liner (Trusoft) were created either without (control) or with the incorporation of 1 of the 3 following drugs at MICs (g of drug per g of resilient material powder): nystatin (Ny, 0.032g/g), chlorhexidine diacetate (Chx, 0.064g/g), and ketoconazole (Ke, 0.128g/g). Specimens were dried; immersed in water for 24 hours and 7 or 14 days; weighed, dried, and weighed again. Data (µg/mm(3)) were analyzed by 3-way ANOVA followed by the Tukey-Kramer honest significant differences test (α=.05). RESULTS: At the 14-day interval, only the addition of Chx (483.0 ±61.0 µg/mm(3)) increased the WS of the tissue conditioner compared with the control group (244.0 ±42.0 µg/mm(3); P<.001). For all periods, the solubility of both materials increased with the addition of Chx (27.7 ±6.1 µg/mm(3)) and Ke (30.9 ±5.3 µg/mm(3)) compared with the control group (22.5 ±6.0 µg/mm(3); P<.001). CONCLUSIONS: After 14 days, the addition of Ny and Ke at MICs in both Softone and Trusoft and addition of Chx in Trusoft did not affect WS. The solubility of the 2 interim materials was not altered by the addition of Ny for up to 14 days.

Surface treatment with methyl formate-methyl acetate increased the shear bond strength between reline resins and denture base resin.

BACKGROUND: Chemical surface treatment increases the shear bond strength (SBS) between hard reline resins (HRRs) and denture base resin. OBJECTIVE: To evaluate the effect of methyl formate-methyl acetate (MF-MA), when used as a surface treatment agent, on the SBS between denture base resin and different HRRs. MATERIALS AND METHODS: One hundred and twenty specimens of heat-polymerised acrylic resin denture base (Meliodent(®) ) were divided into 12 groups. These groups comprised denture base relined with three self-polymerised HRRs [Unifast trad(®) (UT), Tokuyama(®) RebaseII Fast (TR), Ufi gel hard(®) (UG)], and treated with their respective Bonding Agent (BA) or by MF:MA solutions at ratios of 35:65, 25:75, and 15:85 for 15 s. The SBS was measured using a Universal Testing Machine. The data were analysed using two-way anova and post hoc Tukey's analysis at p < 0.05. RESULTS: The highest SBS was in the UT treated with MF:MA at a ratio of 25:75 group, followed by UT treated with MF:MA at ratios of 15:85, 35:65, UT treated with BA, and all UG treated with MF:MA groups. The SBS of the UT treated with MF:MA at a ratio of 25:75 group was significantly higher than those of the groups treated with BA. The SBS of the UG treated with MF:MA groups was significantly higher than control. The TR groups treated with BA or MF:MA groups showed no significant difference in SBS. CONCLUSION: Surface treatment with MF-MA significantly enhanced the SBS of denture base resin and UT and UG compared to that of the groups treated with BA.

Oral health-related quality of life of edentulous patients after complete dentures relining.

BACKGROUND/AIM: Tooth loss affects oral health-related life quality. More than a third of edentulous patients are not fully satisfied with their complete dentures and mainly complain of insufficient stability, retention, and pain during mastication. Solving the problem may include relining by materials that are based on silicone or acrylic. The aim of this study was to determine the level of patients' satisfaction before and after relining upper dentures with soft and rigid liners. METHODS: The patients (n=24) were divided into two study groups. Maxillary denture relining of the first group of patients was performed with hard acrylic based resins while in the second group of patients complete denture was relined with a silicone-based soft liner. They were asked the questions from the specifically adapted the Oral Health Impact Profile Questionnaire for edentulous patients before and three months after relining dentures. RESULTS: After relining the patients showed a higher degree of satisfaction with their dentures in all the tested domains (masticatory function, psychological discomfort, social disability and retention and hygiene). The padents with soft denture relines were more satisfied. CONCLUSION: Refining of maxillary complete dentures significantly positively impacts the quality of life of patients in all the tested domains (masticatory function, psychological discomfort, social disability, pain and oral hygiene). Better results were achieved using a silicone-based soft liner, which recommends it as the material of choice for relining dentures.

Consequences of relining on a maxillary complete denture: A clinical report.

The position of a complete denture may change after relining, especially in the maxillary arch. This report reviews relining techniques and presents a situation with anterior displacement after the relining of a maxillary complete denture. Instead of providing a new denture, the displaced denture was repaired and the original tooth arrangement maintained.

A technique for relining bar-retained overdentures.

This article describes a technique for relining a mandibular bar-retained overdenture that allows recording the soft tissue beneath the bar and makes it possible to replace or modify the retentive bar attachment simultaneously with the reline procedure.

Removable dentures with eclipse-repairing and relining.

UNLABELLED: While utilizing removable dentures, regardless of whether the dentures are acrylic or fabricated of eclipse resin, the need for their filling-relining or their repair frequently arises. The purpose of this study is to display the technicalities of the procedure for rebasing and relining of removable light curing eclipse denture resin. MATERIAL AND METHODS: This study presents cases of relining and repairing of removable dentures fabricated from light curing ECLIPSE resin on patients at the Department for Removable Prosthodontics at the University Dental Clinic Centre in Skopje. CONCLUSION: One of the most significant features of this method of fabrication of removable eclipse dentures and their relining and repairing is the shortened duration of work in the dental laboratory. The displayed mode of rebasing also allows us to maintain one of the advantages of this type of dentures--the absence of allergy stomatitis symptoms.

A conservative approach to rebasing an implant-retained fixed complete denture.

After years of service, the acrylic resin base of an implant-retained fixed complete dental prosthesis may need to be replaced because of the wear of the acrylic resin teeth. The most common methods used by dental laboratories to remove the acrylic resin from the metal framework are either burning with a flame or grinding. Both of these methods risk exposing the dental laboratory technician to hazardous by-products and damaging or contaminating the metal framework or the gold cylinders. This article presents a safe approach to removing acrylic resin while preserving the integrity of the framework. The technique involves heating the prosthesis to beyond the glass transitional temperature of the acrylic resin to allow the resin to be safely peeled off the framework.

Ethanol postpolymerization treatment for improving the biocompatibility of acrylic reline resins.

OBJECTIVE: To evaluate the effect of postpolymerization treatment based on ethanol-aqueous solutions on the residual monomer (RM) content, flexural strength, microhardness, and cytotoxicity of hard chairside reline resins (Kooliner, Ufi Gel Hard). METHODS: After polymerization, specimens were immersed in water, 20%, 50%, or 70% ethanol solutions at 23°C or 55°C for 10 minutes. Controls were left untreated. HPLC was used for the determination of RM content. Specimens were submitted to Vickers microhardness and 3-point loading flexural strength tests. Cytotoxicity of resin eluates was determined on human fibroblasts by assessing cellular mitochondrial function and lactate dehydrogenase release. RESULTS: Higher concentrations of ethanol promoted lower RM content at 55°C in both materials. The mechanical properties were maintained after 50% and 20% ethanol treatments in Kooliner and Ufi Gel Hard, respectively. Specimens submitted to those treatments showed significant reduction on cytotoxicity compared to immersion in hot water, the treatment of choice in the recent literature. SIGNIFICANCE: Immersion of relined dentures in specific ethanol solutions at 55°C for 10 minutes can be considered an effective postpolymerization treatment contributing to increase materials biocompatibility. The proposed protocol is expeditious and easy to achieve with simple equipment in a dental office.

Denture relining as an indicator of residual ridge resorption.

AIM: Residual ridges change in shape and reduce in size due to alveolar bone resorption. Therefore, the purpose was to investigate changes in denture base thickness (DBT) and interocclusal rest space (IRS) with regard to the denture relining procedure. METHODS: The IRS and DBT were measured (before and after denture relining) in the case of 74 patients and their removable dental prostheses by using a precise sliding gauge. The DBT measuring was performed in 6 points for maxillary and in 3 points for mandibular removable dental prosthesis. The IRS values were measured as the distance (in mm) between the incisal edges of the maxillary and mandibular central incisors with patient's mandible in a physiological "rest position" with head and neck in the upright posture. RESULTS: In a group of patients wearing maxillary and mandibular removable dental prosthesis mean values of DBT after denture relining were statistically significantly higher (p <0.05) in almost all measuring points. The IRS mean values after relining were statistically significantly lower (p <0.05). Statistically significant differences (p <0.05) of DBT were also observed in groups of "day-night time" and "day time" denture wearers, and in a group of patients for whom a period shorter than one year had passed since the last tooth extraction and the time when a functional impression for removable dental prostheses was taken. CONCLUSION: The DBT and IRS values change after the denture relining procedure due to the alveolar bone resorption. Therefore, these measures could be used as resorption indicators in dental practice.

Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. OBJECTIVE: This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). MATERIAL AND METHODS: Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37ºC for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (α=0.05) and the failure modes were visually classified. RESULTS: No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. CONCLUSIONS: Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents.

Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin.

UNLABELLED: In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. OBJECTIVE: This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). MATERIAL AND METHODS: Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37 ºC for 48 h. The drug powder concentrations (nystatin 500,000 U--G2; nystatin 1,000,000 U--G3; miconazole 125 mg--G4; miconazole 250 mg--G5; ketoconazole 100 mg - G6; ketoconazole 200 mg--G7; chlorhexidine diacetate 5%--G8; and 10% chlorhexidine diacetate--G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37 ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (α=0.05) and the failure modes were visually classified. RESULTS: No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. CONCLUSIONS: Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents.

Influence of two functional complete-denture impression techniques on patient satisfaction: dentist-manipulated versus patient-manipulated.

This preliminary clinical study aimed to identify the impact of two border-molding techniques (dentist-manipulated and patient-manipulated) on patient satisfaction, the occlusal force at denture dislodgment, and number of pressure sores. Salivary flow rate and residual ridge resorption were analyzed as covariates. Thirty-six edentulous patients in need of a relining of their existing maxillary denture were included. After relining, no significant influence of the border-molding technique on any of the variables investigated could be identified. It can be concluded that the impact of the border-molding technique on patient satisfaction and denture function probably has been overestimated in the past.

Reembasamento em prótese total: material resiliente versus material rígido / Rebasing in total prosthesis: resiliente material versus rigid material

A reabsorção óssea do rebordo alveolar é um processo crônico e irreversível. Com o objetivode minimizar estas alterações, tem-se indicado o reembasamento imediato ou mediato das próteses removíveis. Existem estudos que demonstram que este procedimento traz maior qualidade de uso aos pacientes, pois promove uma adaptação mais satisfatória das mesmas com a mucosa. O objetivo deste artigo é comparar as indicações, vantagens e limitações dos materiais, resilientes e rígidos, indicados para o reembasamento imediato de próteses removíveis em consultório, através de dois casos clínicos. Após o acompanhamento destes casos clínicos, pode-se concluir que para obtenção do sucesso do reembasamento é importante que se respeite a indicação clínica, as propriedades físicas e mecânicas de cada material, bem como a proservação do comportamento do material, através de um rigoroso controle clínico. Também que os reembasadores rígidos podem ser utilizados por um maior período em relação aos resilientes, os quais devido às suas limitações devem ser utilizados apenas em condições transitórias.

The alveolar bone resorption is a cronic and irreversible processo In order to minimize thesechanges, it has been indicated the mediate or immediate relining of dentures. Studies have shown that the procedure for rebasing of dentures brings higher quality of use to patients, as this will promote a more satisfying adaptation of the prosthesis with the mucosa. The aim of this paper is to compare the indications, advantages and limitations of relíning materiais, resilient and hard, in office by two clinical cases. After the clinical monitoring of these cases, it can be concluded that to obtain the success of the relining is important to respect the indication, the physical and mechanical prerties of each material, as well as preservation the behavior of the material, through a rigorous clinical control. Also the hard reline can be used for a longer period compared to resilient, which due to their limitations should only be used in transient conditions.

A modified method for rebasing implant-retained overdentures.

There is a constant need for rebasing implant-retained overdentures because of the inevitable continuous absorption of the underlying residual ridge, which results in a lack of proper occlusion and possible rotation of the denture around the retentive components. This step-by-step article describes all of the clinical and laboratory procedures needed for rebasing a mandibular implant overdenture retained with a bar on two implants, securing an accurate fit. This procedure can be applied successfully for rebasing overdentures with different superstructures (ball attachments or magnets), and for replacing worn or damaged retentive components and matrices.

Relining of prosthesis with auto-polymerizing hard denture reline resins: effect of post-polymerization treatment on flexural strength.

BACKGROUND: It has been suggested that microwave irradiation and prosthesis immersion in hot water after its polymerization may improve mechanical and viscoelastic properties of acrylic resins. PURPOSE: This study was proposed to verify the influence of microwave post-polymerization (PP) treatment over the flexural strength of thermo-polymerizing acrylic resin specimens (QC-20) relined or not with two different composition hard chairside auto-polymerizing reliners [Kooliner (K) and New Truliner (NT)]. MATERIALS AND METHODS: For this study, 50 specimens of 64 x 10 x 3.3 mm were polymerized and distributed into five groups. G1 (control) specimens without relining and PP; G2 specimens relined with K, without PP; G3 specimens relined with NT, without PP; G4 specimens relined with K, with PP (microwave irradiation with 650 W for 5 min); G5 specimens relined with NT, with PP. Tests were performed on a universal testing machine Instron 4411 with compression speed of 5 mm/min. RESULTS: Specimens of K without PP did not show statistically different results (p < 0.05) when compared with control. However, when submitted to PP these specimens showed a significant increase in flexural strength. Specimens of NT showed the lowest flexural strength of all groups, with or without PP when compared with control and K groups. CONCLUSION: Microwave PP (650 W for 5 min) proved to be an effective method of improving the flexural strength of K relined prosthesis. However, it did not seem to affect NT specimens.

Shear bond strength of two chemically different denture base polymers to reline materials.

PURPOSE: This study evaluated the shear bond strengths of light-polymerized urethane dimethacrylate (Eclipse) and heat-polymerized polymethylmethacrylate (Meliodent) denture base polymers to intraoral and laboratory-processed reline materials. MATERIALS AND METHODS: Thirty disks measuring 15 mm diameter and 2 mm thick were prepared for each denture base material following the manufacturers' recommendation. They were relined with Meliodent RR, Kooliner, and Secure reline materials after 1 month of water immersion. Ten additional Eclipse specimens were relined using the same Eclipse resin. A shear bond test was carried out on an Instron machine at a crosshead speed of 1.0 mm/min 24 hours after relining. Data were analyzed using two-way and one-way ANOVAs and post hoc Dunnett's T3 test (p= 0.05). The nature of failure was analyzed under a stereomicroscope. The effect of dichloromethane adhesive on the two denture polymer surfaces and the failed interfaces of mixed and adhesive failures were analyzed under a SEM (scanning electron microscope). RESULTS: Two-way ANOVA showed significant differences in the shear bond strength values as a function of the denture base polymers, reline materials, and their interaction (p < 0.05). One-way ANOVA showed significant differences in shear bond strength values among denture base-reline combinations (p < 0.05) except for Meliodent-Kooliner and Eclipse-Meliodent RR relines. Meliodent showed the highest shear bond strength value when relined with Meliodent RR (14.5 +/- 0.5 MPa), and Eclipse showed the highest value with Eclipse relining (11.4 +/- 0.6 MPa). Meliodent denture base showed adhesive, cohesive, and mixed failure, while all Eclipse showed adhesive failure with various reline materials. CONCLUSION: The two chemically different denture base polymers showed different shear bond strength values to corresponding reline materials.

Effect of relining method on dimensional accuracy of posterior palatal seal. An in vitro study.

PURPOSE: The posterior palatal seal contributes to the retention of the complete denture. Distortion of this area can occur during reline procedures. The purpose of this study was to evaluate the dimensional accuracy of various denture relining methods and materials on the maxillary posterior palatal seal area. MATERIALS AND METHODS: A stainless steel cast was constructed from a maxillary edentulous cast. Fifty identical complete dentures were fabricated on 50 definitive casts made from the original metal cast. Five relining methods and materials were evaluated during this study, in regards to posterior palatal seal distortion: (I) laboratory conventional heat-polymerizing method (Lucitone), (II) laboratory heat/pressure-polymerizing method (SR-Ivocap), (III) laboratory autopolymerizing method (Perm), (IV) chairside autopolymerizing method (Tokuso Rebase), and (V) chairside light-polymerizing method (Astron). The dimensional changes of the posterior palatal seal areas were determined by placing a low-viscosity silicone impression material between the metal cast and the tissue surface of the relined dentures. The silicone thickness was measured at five predetermined points, under a measuring microscope. Statistical analysis was performed using descriptive statistics, one-way analysis of variance, and Student-Newman-Keuls tests (alpha= 0.05). RESULTS: The gap at the posterior palatal seal area ranged from 68.76 to 331.55 microm, when measured at the five predetermined points. Group IV exhibited the smallest mean gap (137.62 microm) and Group I revealed the largest mean discrepancy (192.35 microm). The different relining methods and materials presented statistically significant differences (p < 0.0001). CONCLUSION: The chairside autopolymerizing method exhibited smaller gap recordings than the rest of the tested complete denture relining methods.