OBJECTIVES: In mandibular edentulism, the treatment option with a two-interforaminal implant-retained bridge and a removable partial denture is rarely evaluated in literature. The aim of this in vitro study was to evaluate the stress distribution of this treatment option by comparing it with traditional treatment options with interforaminal implants in the edentulous mandible. MATERIALS AND METHODS: Two interforaminal implants were placed in a formalin-fixed cadaver mandible, and overdentures with three different types of attachments were fabricated: (1) two ball attachments and an overdenture, (2) a Dolder bar and an overdenture, and (3) screw-retained two-implant inter-canine porcelain fused to a metal bridge and an implant-assisted removable denture (IARD) with precision attachments. Three biting conditions were generated for each denture type, and the strains were documented under vertical loading of 100 N. RESULTS: The calculated strain values from measured strains in all measurement sites and loading conditions for the screw-retained two-implant inter-canine porcelain fused to a metal bridge and a cast framework partial denture with precision attachments situation were lower than in the other scenarios (P<0.05). CONCLUSION: Within the limitations of the present study, it can be concluded that an IARD may be a reasonable and valuable alternative to ball attachments or a bar in two interforaminal implants, especially when the patients prefer to be able to show their teeth even when they take out their removable dentures.
Cadaver ; Dental Porcelain ; Denture, Overlay ; Denture, Partial ; Denture, Partial, Removable ; Dentures ; Humans ; In Vitro Techniques ; Mandible ; Tooth

OBJECTIVES: In mandibular edentulism, the treatment option with a two-interforaminal implant-retained bridge and a removable partial denture is rarely evaluated in literature. The aim of this in vitro study was to evaluate the stress distribution of this treatment option by comparing it with traditional treatment options with interforaminal implants in the edentulous mandible. MATERIALS AND METHODS: Two interforaminal implants were placed in a formalin-fixed cadaver mandible, and overdentures with three different types of attachments were fabricated: (1) two ball attachments and an overdenture, (2) a Dolder bar and an overdenture, and (3) screw-retained two-implant inter-canine porcelain fused to a metal bridge and an implant-assisted removable denture (IARD) with precision attachments. Three biting conditions were generated for each denture type, and the strains were documented under vertical loading of 100 N. RESULTS: The calculated strain values from measured strains in all measurement sites and loading conditions for the screw-retained two-implant inter-canine porcelain fused to a metal bridge and a cast framework partial denture with precision attachments situation were lower than in the other scenarios (P<0.05). CONCLUSION Within the limitations of the present study, it can be concluded that an IARD may be a reasonable and valuable alternative to ball attachments or a bar in two interforaminal implants, especially when the patients prefer to be able to show their teeth even when they take out their removable dentures.

PURPOSE: The midline fracture of maxillary complete dentures is a frequently encountered complication. The purpose of this study was to assess the effect of frenulum height on midline strains of maxillary complete dentures. MATERIALS AND METHODS: A removable maxillary complete denture was fabricated and duplicated seven times. Four different labial frenulum heights were tested for stresses occurring on the palatal cameo surface. The strains were measured with strain gauges placed on 5 different locations and the stresses were calculated. To mimic occlusal forces bilaterally 100 N of load was applied from the premolar and molar region. RESULTS: A statistically significant association between the height of the labial frenulum and the calculated stresses and strains was shown (P<.05) predominantly on the midline and especially on the incisive papilla. The results showed that stress on the anterior midline of the maxillary complete denture increases with a higher labial frenulum. CONCLUSION: Within the limitations of this in vitro study, it can be concluded that the stress on the anterior midline of the maxillary complete denture increases with a higher labial frenulum. Surgical or mechanical precautions should be taken to prevent short-term failure of maxillary complete dentures due to stress concentration and low cycle fatigue tendency at the labial frenulum region.
Bicuspid ; Bite Force ; Denture Bases* ; Denture, Complete ; Dentures* ; Fatigue ; Molar ; Palate

PURPOSE: The purpose of this in vitro study was to investigate the flexural properties of a recently introduced urethane dimethacrylate denture base material (Eclipse) after being repaired with two different materials. MATERIALS AND METHODS: Two repair groups and a control group consisting of 10 specimens each were generated. The ES group was repaired with auto-polymerizing polymer. The EE group was repaired with the Eclipse. The E group was left intact as a control group. A 3-point bending test device which was set to travel at a crosshead speed of 5 mm/min was used. Specimens were loaded until fracture occurred and the mean displacement, maximum load, flexural modulus and flexural strength values and standard deviations were calculated for each group and the data were statistically analyzed. The results were assessed at a significance level of P<.05. RESULTS: The mean "displacement", "maximum load before fracture", "flexural strength" and "flexural modulus" rates of Group E were statistically significant higher than those of Groups ES and EE, but no significant difference (P>.05) was found between the mean values of Group ES and EE. There was a statistically significant positive relation (P<.01) between the displacement and maximum load of Group ES (99.5%), Group EE (94.3%) and Group E (84.4%). CONCLUSION: The more economic and commonly used self-curing acrylic resin can be recommended as an alternative repair material for Eclipse denture bases.
Acrylic Resins ; Denture Bases* ; Dentures* ; Methacrylates ; Polymers ; Polyurethanes ; Urethane*