Slide 2: DEPARTMENT OF PROSTHODONTICS SEMINAR TOPIC
PALATAL SEAL POSTERIOR PALATAL SEAL : POSTERIOR PALATAL SEAL Introduction
The denture must be seal all along its boundaries.
The seal is known as peripheral seal.
The posterior palatal seal is the part of this.
The drapping of tissues over the buccal and lingual borders provides an effective seal in these region. Slide 4: The seal along the posterior border of maxillary denture is known as posterior palatal seal.
However the posterior border of maxillary denture requires the different kind of seal because at the posterior aspect of denture in the area of the soft palate there are no cheek tissues to seal the denture border. DEFINITION : DEFINITION The soft tissues at or along the junction of the hard and soft palate on which pressure with in the physiological limits of the tissues can be applied by a denture to aid in the retention of the denture.
The posterior palatal seal is formed through both hamular
notches and across the palate over the vibrating line.
Prevents food accumulation beneath the denture
Maintain contact with the moving soft palate and reduces the patient’s awareness and thus reduces gag reflex.
As the posterior denture border will closely approximate the soft palatal tissues and compensates for the volumetric shrinkage that occurs during the polymerization of methyl methacrylate resin. COMPONENTS OF POSTERIOR PALATAL SEAL : COMPONENTS OF POSTERIOR PALATAL SEAL PTERYGOMAXILLARY SEAL
This is the part of the posterior palatal seal
that extends across the
The pterygomaxillary seal is placed in hamular notch
it is located behind the maxillary tuberosity.
It is located using a T-burnisher, it is moved along
posteriorily untill a soft depression is felt
POST PALATAL SEAL
This is the part of posterior palatal seal that
between the two maxillary tuberosities. BOUNDARIESOF POSTERIOR PALATAL SEAL : BOUNDARIESOF POSTERIOR PALATAL SEAL ANTERIORLY – Anterior vibrating line
POSTERIORLY – Posterior vibrating line
LATERALLY – Pterygomaxillary seal Slide 8: VIBRATING LINE
The imaginary line across the posterior part
of the palate marking the division between
the movable and immovable tissues of the
soft palate which can be identified when the
movable tissues are moving. Slide 9: ANTERIOR VIBRATING LINE
It is an imaginary line
located at the
junction of attached tissues
hard palate and
the movable tissue of the
immediately adjacent soft palate.
LOCATED BY –
Patient is asked to say “ah” with short
vigorous bursts. POSTERIOR VIBRATING LINE : POSTERIOR VIBRATING LINE It is an imaginary line
located at the junction
of the soft palate that shows
and the soft palate that shows marked
LOCATED BY –
It is located by asking the patient to say “ah” in
short but non vigorous fashion. POINTS SHOULD BE REMEMBER WHILE RECORDING THE PPS : POINTS SHOULD BE REMEMBER WHILE RECORDING THE PPS Presence of palatine torus
Position of fovea palatina
Presence of mid palatine fissure
Patient with thick ropy saliva TECHNIQUES OF RECORDING THE PPS : TECHNIQUES OF RECORDING THE PPS [A] ARBITRARY TECHNIQUE
[B] Physiologic TECHNIQUE
Fluid wax Technique
Extended Palatal Technique
Stick Compound Technique CONVENTIONAL TECHNIQUE : CONVENTIONAL TECHNIQUE Stage of recording
After final impression
Locate the hamular notches
Marked with indelible pencil
Posterior vibrating line marked by
to say “ah” non vigorously.
The hamular notch and
posterior vibrating line are
joined using indelible pencil Slide 14: The marking transferred to master cast.
Anterior vibrating line marked
by asking the patient to
Perform valsalva manuver.
The area between anterior
and posterior vibrating line
is scored on the cast. BOUCHER’S TECHNIQUES : BOUCHER’S TECHNIQUES Stage of recording – During jaw relations
Palpate hamular notch and marked with indelible pencil.
Patient ask to say “ah” and vibrating line marked with indelible pencil.
The earlier markings joined with this
↓ Slide 16: Trial denture base inserted and line
is transferred to it
Excess base plate removed
Placed on cast and posterior
limit of base plate marked
V – Shaped groove is carved on the cast FLUID WAX TECHNIQUE : FLUID WAX TECHNIQUE Stage of recording
After making the final impression.
Zinc oxide eugenol or plaster impression are preferred
Both the vibrating lines are marked in the mouth and transferred on to the impression
Korrecta wax no. 4,Lowa wax,
H-L physiologic paste or
Adaptol may be used
The molten wax is painted between the two lines Slide 18: The patient’s head should
be downward by 30°
The impression reinserted in
the mouth and hold for 4 to 6 min
The wax should terminate in a
knife edge near the anterior
Excess wax is trimmed off EXTENDED PALATAL TECHNIQUE : EXTENDED PALATAL TECHNIQUE Stage of recording
After border moulding
Denture border is extended 8.2 mm beyond the anterior vibrating line
Head is fixed downward 30°
Application of green stick compound to the seal area
An angular depression is seen in the compound STICK COMPOUND TECHNIQUE : STICK COMPOUND TECHNIQUE Stage of recording
During border moulding before final impression made
Application of stick compound on the tray between both
The vibrating lines
Pressed gently in the mouth Slide 21: ↓
Excess material beyond the anterior vibrating line is trimmed off
The region is flamed lightly and the process is repeated
Dull appearance of compounds indicates positive contacts ERRORS IN RECORDING PPS : ERRORS IN RECORDING PPS Over extension
Over postdamming Slide 23: Thank you