How to Select a Partial Denture Attachment:
The choice in partial denture attachments is between Non-resilient and Resilient. Non-resilient (rigid) attachments are highly stable connectors with very slight movement in function. Some may be used for segmenting fixed partial dentures to simplify future case conversion to a removable restoration. In distal extension partial denture cases, occlusal forces are directed relatively evenly to both the abutment teeth and the edentulous ridge. Therefore, rigid attachments are kinder to the edentulous ridge than are resilient attachments. When abutment teeth are stable, rigid attachments are often the connectors of choice.
Resilient attachments are stress directing attachments for Kennedy Class I and II cases which place occlusal load on both abutment teeth and the edentulous ridge. The ridge is more heavily loaded than when using rigid attachments, while the abutment teeth are more lightly loaded.
The following are general guidelines that may be used to help you to decide on which attachment might be best for a particular situation. They are based on 80 years of experience with dental attachments, but the final choice must be based on the particular dentist's philosophy, education, and experience. Based on your answers to the following question you will choose either Non-Resilient Attachments or Resilient Attachments.
1. Bone Support Around the Abutments - If the bone support is good (0-20% bone loss), or if abutments can be made strong by splinting, non-resilient attachments are the connectors of choice. If the bone support is fair (20%-40% bone loss), the choice will most often be resilient attachments. If the bone loss is 40% or greater, more than likely the abutments need to be reduced to the height of the gingival tissue and the roots used to retain an overdenture.
2. The Condition of The Ridge - If the edentulous ridge has little loss of bone, either resilient or non-resilient attachments could be used. But, if the ridge is significantly resorbed, non-resilient attachments would most likely be indicated.
3. Is the opposing arch non-resilient (rigid) or resilient? Two resilient prostheses should generally not oppose each other, as two mobile occlusal planes will impair chewing efficiency.
Proper Measurements for Attachments
Sterngold works hard to make using attachments easy for you. In this catalog, we provide our best advice on space requirements based on extensive practical experience.
Each attachment description lists the minimum space required for placement of the attachment, to assure a high rate of success and long-term function. Allowance is already made for restorative materials, such as dental casting alloys or denture acrylic, surrounding and holding the attachment component. With this information you can measure a study cast and decide if an attachment can be used in the available space.
These allowances are:
• Denture acrylic thickness occlusal to extracoronal attachment components, bars and overdenture attachments (influences Height), 1mm
• Denture acrylic thickness lateral to attachment components (influences Removable Component Width), 1mm on each side.
• Casting alloy thickness between a box preparation axial wall and a metal, intracoronal, precision attachment female (influences Prep Depth), 0.4mm
• Casting alloy thickness for root cap coping (influences Height), 0.5mm.
Working with Metal Attachments
Depending on the attachment's design, metal components are anchored in denture acrylic, soldered to a casting, or invested along with a wax pattern and cast against with a dental alloy. Use an alloy with a casting temperature at least 100°F (40°C) below the lowest value of the component's melting range when casting against an attachment component.
Melting Ranges of Attachments
Ceramacast components
Degrees F: 2600-2760
Degrees C: 1425-1515
Ceramicor components
Degrees F: 2550-2715
Degrees C: 1400-1490
Doral components
Degrees F: 1705-1860
Degrees C: 930-1015
Elitor components
Degrees F: 1615-1725
Degrees C: 880-940
Iridium-platinum components
Degrees F: 3300-3360
Degrees C: 1820-1850
NPS components
Degrees F: 2700-2850
Degrees C: 1480-1565
OSV components
Degrees F: 1885-2010
Degrees C: 1030-1100
The choice in partial denture attachments is between Non-resilient and Resilient. Non-resilient (rigid) attachments are highly stable connectors with very slight movement in function. Some may be used for segmenting fixed partial dentures to simplify future case conversion to a removable restoration. In distal extension partial denture cases, occlusal forces are directed relatively evenly to both the abutment teeth and the edentulous ridge. Therefore, rigid attachments are kinder to the edentulous ridge than are resilient attachments. When abutment teeth are stable, rigid attachments are often the connectors of choice.
Resilient attachments are stress directing attachments for Kennedy Class I and II cases which place occlusal load on both abutment teeth and the edentulous ridge. The ridge is more heavily loaded than when using rigid attachments, while the abutment teeth are more lightly loaded.
The following are general guidelines that may be used to help you to decide on which attachment might be best for a particular situation. They are based on 80 years of experience with dental attachments, but the final choice must be based on the particular dentist's philosophy, education, and experience. Based on your answers to the following question you will choose either Non-Resilient Attachments or Resilient Attachments.
1. Bone Support Around the Abutments - If the bone support is good (0-20% bone loss), or if abutments can be made strong by splinting, non-resilient attachments are the connectors of choice. If the bone support is fair (20%-40% bone loss), the choice will most often be resilient attachments. If the bone loss is 40% or greater, more than likely the abutments need to be reduced to the height of the gingival tissue and the roots used to retain an overdenture.
2. The Condition of The Ridge - If the edentulous ridge has little loss of bone, either resilient or non-resilient attachments could be used. But, if the ridge is significantly resorbed, non-resilient attachments would most likely be indicated.
3. Is the opposing arch non-resilient (rigid) or resilient? Two resilient prostheses should generally not oppose each other, as two mobile occlusal planes will impair chewing efficiency.
Proper Measurements for Attachments
Sterngold works hard to make using attachments easy for you. In this catalog, we provide our best advice on space requirements based on extensive practical experience.
Each attachment description lists the minimum space required for placement of the attachment, to assure a high rate of success and long-term function. Allowance is already made for restorative materials, such as dental casting alloys or denture acrylic, surrounding and holding the attachment component. With this information you can measure a study cast and decide if an attachment can be used in the available space.
These allowances are:
• Denture acrylic thickness occlusal to extracoronal attachment components, bars and overdenture attachments (influences Height), 1mm
• Denture acrylic thickness lateral to attachment components (influences Removable Component Width), 1mm on each side.
• Casting alloy thickness between a box preparation axial wall and a metal, intracoronal, precision attachment female (influences Prep Depth), 0.4mm
• Casting alloy thickness for root cap coping (influences Height), 0.5mm.
Working with Metal Attachments
Depending on the attachment's design, metal components are anchored in denture acrylic, soldered to a casting, or invested along with a wax pattern and cast against with a dental alloy. Use an alloy with a casting temperature at least 100°F (40°C) below the lowest value of the component's melting range when casting against an attachment component.
Melting Ranges of Attachments
Ceramacast components
Degrees F: 2600-2760
Degrees C: 1425-1515
Ceramicor components
Degrees F: 2550-2715
Degrees C: 1400-1490
Doral components
Degrees F: 1705-1860
Degrees C: 930-1015
Elitor components
Degrees F: 1615-1725
Degrees C: 880-940
Iridium-platinum components
Degrees F: 3300-3360
Degrees C: 1820-1850
NPS components
Degrees F: 2700-2850
Degrees C: 1480-1565
OSV components
Degrees F: 1885-2010
Degrees C: 1030-1100