TOPIC: OVERDENTURES
🎯 KEY POINTS:
🔹Overdenture primarily preserves bone, preserves proprioception and enhances patient’s manipulative skills.
🔹Application of low concentration stannous fluoride or 0.5% APF gel is recommended on abutment teeth to reduce caries rate.
🔹Overdenture is also called biologic denture, telescopic denture, onlay denture, hybrid denture, root-supported denture and superimposed denture.
🔹Overdenture treatment is highly useful in the patients with congenital anomalies such as cleft palate, microdontia, amelogenesis imperfecta and dentinogenesis imperfecta.
🔹In immediate overdenture concept, certain poorly prognosed teeth are removed and denture is inserted over the remaining teeth until complete healing of the extraction site occurs.
🔹Extracoronal attachment For example: Studs (Gerber, Dalla Bona, Rotherman,etc.), bar, auxiliary attachments
🔹Intracoronal attachment For example: Zest, Ginta, etc.
🔹Immediate overdenture concept was popularized by J.L. Lord and S.Teel (1969).
🔍 DEFINITIONS:
🔺Overlay dentures or Overdenture: Any removable dental prosthesis that covers and rests on one or more remaining natural teeth, the roots of natural teeth, and/or dental implants. (GPT 8th Ed)
🔺Extracoronal Attachment: Any prefabricated attachment for support and retention of a removable dental prosthesis. The male and female components are positioned outside the normal contour of the abutment tooth (GPT 8th Ed)
🔺Intracoronal Attachment: Any prefabricated attachment for support and retention of a removable dental prothesis. The male and female components are positioned within the normal contour of the abutment tooth. (GPT 8th Ed)
🔎 PRINCIPLES OF OVERDENTURE
🔸It maintains the teeth as part of the residual ridge. The denture rests over the remaining teeth or root and minimizes its vertical movement.
🔸It decreases the rate of resorption. Overdenture preserves the alveolar bone and decreases the rate of resorption.
🔸There is preservation of the periodontium along with the teeth. This increases the manipulative skills of the patient in handling the denture.
🔸Reduction of the retained teeth to establish a favorable crown–root ratio.
🔍 CLASSIFICATION OF OVERDENTURES:
👉 On the Basis Of Method of Abutment Preparation:
🔹Non coping
🔹Coping
🔹Attachments
👉 On the Basis of Method of Retention:
🔹Copings
🔹Attachments
🔹Sleeve coping prosthesis
🔹Submucosal vital root retention
🔹Implant supported
👉 On the Basis of Time of Fabrication:
🔹Immediate overdenture
🔹Transitional overdenture
🔹Training overdenture
👉 On the Basis of Type of Tooth-Supported Overdentures:
🔹Tooth-supported conventional complete
overdenture
🔹Tooth-supported immediate complete overdenture
👉 On the Basis of Type of Design:
🔹Bare root
🔹Telescopic
🔹Attachment fixation overdenture
🔍 RATIONALE FOR RETAINING TEETH CATEGORIZED INTO THREE POINTS:
🔸Preservation of proprioception
🔸Alveolar bone preservation
🔸Occlusal forces in overdentures
🔍 TYPES OF OVERDENTURE DESIGNS
💡The basic overdenture designs:
🔸Bare root overdenture
🔸Telescopic overdenture
🔸Attachment fixation overdenture
🔍 TYPES OF PRIMARY COPINGS
🔸Long coping
🔸Medium coping
🔸Short coping
🔍 TYPES OF OVERDENTURE ATTACHMENTS
💡 Classification of overdenture attachments on the basis of shape, design and primary area of their use:
👉 Coronal
A) Intracoronal – radicular attachments such as Zest, Ginta, etc.
B) Extracoronal
♦️ Extracoronal
A) Telescope stud attachments
B) Bar attachments – joints, units
C) Auxiliary attachments:
(i) Screw units
(ii) Pawl connectors
(iii) Bolts
(iv) Stabilizers/balancers
(v) Interlocks
(vi) Pins/screw
(vii) Rests
💠Attachments in Overdenture Design
📣 Commonly used attachments are:
🔸Gerber Attachments
🔸Resilient Gerber Attachment
🔸Ceka Attachments
🔸Zest Anchor
🔸Rothermann Attachment
🔸Introfix Attachment
🔸Magnets
🔸Bar Attachments
📌 Bar Attachments:
👉Two Types:
A. Bar units:
B. Bar joints: