Precision attachments/ orthodontic seminars

PRECISIONPRECISION
ATTACHMENTSATTACHMENTS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
www.indiandentalacademy.comwww.indiandentalacademy.com

DEFINITIONSDEFINITIONS
The term precision denotes ‘the quality or state ofThe term precision denotes ‘the quality or state of
being precise’.being precise’.
PRECISION ATTACHMENTSPRECISION ATTACHMENTS
A precision attachment is a retainer used in fixedA precision attachment is a retainer used in fixed
and removable partial denture constructionand removable partial denture construction
consisting of a metal receptacle and a closelyconsisting of a metal receptacle and a closely
fitting part, the former is usually contained withinfitting part, the former is usually contained within
the normal or expanded contours of the crown ofthe normal or expanded contours of the crown of
the abutment tooth, and the latter is attached to athe abutment tooth, and the latter is attached to a
pontic or to the denture frame workpontic or to the denture frame work

Intracoronal PrecisionIntracoronal Precision
AttachmentsAttachments
The bulk of the soldered or cast on portion of theThe bulk of the soldered or cast on portion of the
joint lies within the anatomical contours of thejoint lies within the anatomical contours of the
treated teethtreated teeth
Extracoronal precisionExtracoronal precision
attachmentsattachments
Are used to join a prosthesis to a retainer, partAre used to join a prosthesis to a retainer, part
of all of their mechanisms is outside the contourof all of their mechanisms is outside the contour
of the retainerof the retainer

INDICATIONSINDICATIONS
 Movable joints in fixed movable bridge work.Movable joints in fixed movable bridge work.
 As stress breaker in free end saddles andAs stress breaker in free end saddles and
bridges.bridges.
 Intracoronal attachments are effective retainersIntracoronal attachments are effective retainers
for removable partial dentures.for removable partial dentures.
 As a connector for sectional dentures.As a connector for sectional dentures.
 Sections of a fixed prosthesis may beSections of a fixed prosthesis may be
connected with intracoronal attachments.connected with intracoronal attachments.

CONTRAINDICATIONSCONTRAINDICATIONS
 Sick and the senile patients (Prosthesis withSick and the senile patients (Prosthesis with
attachments must be inserted along oneattachments must be inserted along one
precise path of insertion, the patient mustprecise path of insertion, the patient must
posses an average degree of manual skill).posses an average degree of manual skill).
 PeriodontosisPeriodontosis
 Abnormally high carries rate.Abnormally high carries rate.
 Inadequate space to employ them (Teeth thatInadequate space to employ them (Teeth that
are very narrow facio-lingually).are very narrow facio-lingually).

ADVANTAGESADVANTAGES
 The labial or buccal clasp arm can beThe labial or buccal clasp arm can be
eliminated altogether. This makes spectaculareliminated altogether. This makes spectacular
improvement in the esthetic excellence of aimprovement in the esthetic excellence of a
denture especially in the maxillary arch.denture especially in the maxillary arch.
 Precision attachments are less stressful to thePrecision attachments are less stressful to the
abutment teeth than conventional clasps.abutment teeth than conventional clasps.
Precision attachment is located deep within thePrecision attachment is located deep within the
confines of the tooth therefore all stress isconfines of the tooth therefore all stress is
directed along long axis of the teeth.directed along long axis of the teeth.

DISADVANTAGESDISADVANTAGES
 Where a replacement tooth should ideally beWhere a replacement tooth should ideally be
positioned.The tooth may have to be extensivelypositioned.The tooth may have to be extensively
cut to provide requisite space to accommodatecut to provide requisite space to accommodate
intracoronal attachment.intracoronal attachment.
 A bulge in the crown is created by intracoronalA bulge in the crown is created by intracoronal
attachment.attachment.
 The attachment is subject to wear as a result ofThe attachment is subject to wear as a result of
friction between metal parts. As wear occurs,friction between metal parts. As wear occurs,
male portion fits more loosely thus permittingmale portion fits more loosely thus permitting
excessive movement and threat of injury toexcessive movement and threat of injury to
abutment teeth.abutment teeth.

 The extracoronal type of retainer extends outThe extracoronal type of retainer extends out
from the tooth near the gingival border there mayfrom the tooth near the gingival border there may
be a gingival irritation followed by usualbe a gingival irritation followed by usual
inflammatory sequela.inflammatory sequela.
 The extracoronal type of attachment must occupyThe extracoronal type of attachment must occupy
the space immediately adjacent to abutmentthe space immediately adjacent to abutment
tooth, which is precisely .tooth, which is precisely .

Intracoronal attachmentsIntracoronal attachments
This type of attachment is within the anatomicalThis type of attachment is within the anatomical
contour of the crown of natural tooth. It providescontour of the crown of natural tooth. It provides
rigid connection between the saddle and abutmentrigid connection between the saddle and abutment
tooth and provides frictional contact between thetooth and provides frictional contact between the
parallel surfaces of the flange and slot. The mainparallel surfaces of the flange and slot. The main
problem encountered in the use of intracoronalproblem encountered in the use of intracoronal
attachments is providing sufficient room within theattachments is providing sufficient room within the
contour of the abutment tooth to accommodate thecontour of the abutment tooth to accommodate the
female part.female part.

Extra Coronal AttachmentExtra Coronal Attachment
These attachments have all or a part of theirThese attachments have all or a part of their
mechanism lying outside the contour of the crownmechanism lying outside the contour of the crown
of the abutment tooth. As a result loads falling onof the abutment tooth. As a result loads falling on
the tooth via the attachment are applied outsidethe tooth via the attachment are applied outside
the long axis of the tooth. These attachmentsthe long axis of the tooth. These attachments
require a well supported abutment tooth.require a well supported abutment tooth.

CLASSIFICATIONCLASSIFICATION
Intracoronal attachmentsIntracoronal attachments
 Resilient intracoronal attachmentsResilient intracoronal attachments
(Resilient attachments allows a degree of(Resilient attachments allows a degree of
permitted movement to take account of disparitypermitted movement to take account of disparity
between resilience of teeth and supportingbetween resilience of teeth and supporting
tissues).tissues). Eg. Crismani 689-A, Crismani 689-D.Eg. Crismani 689-A, Crismani 689-D.
 Non-resilient intracoronal attachmentsNon-resilient intracoronal attachments
(Rigid attachments).(Rigid attachments).

Extracoronal attachmentsExtracoronal attachments
 Resilient extracoronal attachmentsResilient extracoronal attachments
Eg. Crismani Resilience joint, Dalbo resilienceEg. Crismani Resilience joint, Dalbo resilience
joint.joint.
 Non-resilient extracoronal attachmentsNon-resilient extracoronal attachments
Eg. Spang Stabilex, Spang ConexEg. Spang Stabilex, Spang Conex

Attachments can be classifiedAttachments can be classified
depending on whether they are pre-depending on whether they are pre-
fabricated or fabricated in thefabricated or fabricated in the
laboratorylaboratory..
 ThoseThose pre-fabricatedpre-fabricated by the manufacturer isby the manufacturer is
called as precision attachment. Pre-fabricatedcalled as precision attachment. Pre-fabricated
type of attachment is usually made of precioustype of attachment is usually made of precious
metal. Eg. Channel-shoulder-pin attachmentsmetal. Eg. Channel-shoulder-pin attachments
(C.S.P.)(C.S.P.)
 Plastic attachmentsPlastic attachments (castable)(castable)
Simple, yet precise, indicated for removable andSimple, yet precise, indicated for removable and
fixed dentures. Easy to handle, no soldering,fixed dentures. Easy to handle, no soldering,
and all of them burn without any residue.and all of them burn without any residue.
Eg. Reinefert’s Unirest B, Mortice Rest.Eg. Reinefert’s Unirest B, Mortice Rest.

IndicationsIndications
 Roots are retained for conservation of theRoots are retained for conservation of the
alveolar ridge.alveolar ridge.
 Over denture support, stability and retention areOver denture support, stability and retention are
all important considerations.all important considerations.
 Coping coverage is indicated for caries control.Coping coverage is indicated for caries control.
 Weak abutments require splinting (though someWeak abutments require splinting (though some
attachments can be utilized without splinting theattachments can be utilized without splinting the
roots).roots).

 The dentist desires controlled adjustableThe dentist desires controlled adjustable
retention.retention.
 Comfort and patient acceptance are majorComfort and patient acceptance are major
concerns. (An attachment-retained overdentureconcerns. (An attachment-retained overdenture
feels more like bridge work than a non-feels more like bridge work than a non-
attachment overdenture.)attachment overdenture.)
 The dentist wishes to minimize, or maximize, theThe dentist wishes to minimize, or maximize, the
amount of denture-bearing mucosa.amount of denture-bearing mucosa.
 The dentist desires a more balanced distributionThe dentist desires a more balanced distribution
of mastication load between abutments andof mastication load between abutments and
tissue than is possible with a conventionaltissue than is possible with a conventional
telescopic overdenture.telescopic overdenture.www.indiandentalacademy.comwww.indiandentalacademy.com

DisadvantageDisadvantage
 More expensive than conventional telescopicMore expensive than conventional telescopic
overdenture.overdenture.
 More difficult to fabricate.More difficult to fabricate.
 More difficult to maintain.More difficult to maintain.
 Some attachments are bulky and therefore maySome attachments are bulky and therefore may
cause esthetic and occlusal space problems.cause esthetic and occlusal space problems.
 Patients with limited manual dexterity may havePatients with limited manual dexterity may have
difficulty inserting the prosthesis.difficulty inserting the prosthesis.

Superiority of Attachment-FixationSuperiority of Attachment-Fixation
OverdentureOverdenture
The attachment-fixation overdenture is farThe attachment-fixation overdenture is far
superior to other types of overdentures or othersuperior to other types of overdentures or other
forms of overlay prostheses. It can more closelyforms of overlay prostheses. It can more closely
approximate the results obtained with fixedapproximate the results obtained with fixed
bridgework and precision partial denturebridgework and precision partial denture
prosthetics than is possible with telescopicprosthetics than is possible with telescopic
overdentures or complete dentures. The patientoverdentures or complete dentures. The patient
is more secure in its use than with a completeis more secure in its use than with a complete
denture. Thus, he enjoys increased comfort,denture. Thus, he enjoys increased comfort,
function, and a more natural appearance.function, and a more natural appearance.

Precision attachments/ orthodontic seminars

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