neutral zone impression technique
TRANSCRIPT
Neutral Zone Impression Technique
SHAISTA ZAFAR
NEUTRAL ZONE
Gahan and Walmsley (2005) defined neutral zone as the
area in the mouth where during function, the forces
of the tongue pressing outwards are neutralised
by the forces of the cheeks and lips pressing inwards.
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NEUTRAL ZONE
IMPRESSION TECHNIQUE
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It’s a physiological and functional approach that is widely and concisely described as a treatment modality for unstable lower complete denture cases
COMMON COMPLAINTS OF LOWER COMPLETE
DENTURE
PAIN
LOOSENESS-being the most common complain!
MOST EFFECTIVE FOR
who have had
numerous unstable, unretentive lower complete dentures.
EVEN AFTER
HAVING..
LOWER DENTURE??
Atrophies mandible>maxilla
Mandible has less residual ridge for retention and support
Difficulty for positioning the teeth to produce a stable denture
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RESIDUAL RIDGE RESORPTION
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LABIAL RESORPTION
BUCCAL
RESORPTIO
N
LINGUAL
RESORPTION
LINGUAL
RESORPTION
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FUNCTIONAL FORCES
FORCESINWARD FORCES
OUTWARD FORCES
BuccinatorModiolus
Orbicularis orisTONGUE
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INDICATIONS
CATIONSIONS
25
Severely atrophic mandibular ridge
High mentalis attachment
Neuromuscular disease
Atypical shape of oral structures
Trauma
Systemic disease
Locate optimal position for implants.
Partial glossectomy
Motor nerve damage to the tongue
AIM
Is to improve denture stability by constructing a
denture that is shaped by muscle function
and is in harmony with the surrounding oral structures.
OTHER ADVANTAGE
S
Improved stability and retention
Posterior teeth will be correctly positioned allowing sufficient tongue space
Reduced food trapping adjacent to the molar teeth
Good aesthetics due to facial support.
MATERIAL USED FOR
NEUTRAL ZONE IMPRESSION
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Stock trays
Impression Compound
Zinc Oxide Eugenol
Custom tray
Green stick
Orthodontic Ni/Ti wires
Modeling Wax
Tissue Conditioners
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CASE REPORT
Free template from www.brainybetty.com 33EDENTULOUS MAX ARCH EDENTULOUS MANDIBULAR ARCH
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CLINICAL TECHNIQUE
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:Preliminary impression with impression compoundSTEP 1
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STEP 2 Wash impression with Zinc Oxide Eugenol
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A lower acrylic special tray with metal spurs to aid retention of the
impression material
STEP 3
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JAW RELATIONSTEP 4:
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STEP 5STEP 5: Occlusal pillars built in green stick to establish the occlusal height
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STEP 6
Tissue conditioner being molded with the mouth movements
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STEP 7: The tray now kept on the cast
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STEP 8: Plaster index formed around the neutral zone impression Neutral zone impression removed to make the wax rim
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STEP 9: Wax rim formed
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STEP 10: Teeth set up in neutral zone
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CONCLUSIONS
Special impression techniques are useful for the construction of lower complete dentures on highly atrophic ridges in cases where dental implants are not possible
Neutral zone impression technique is a useful technique aims to construct a denture in muscle balance, it is relatively simple but it is demanding both clinically and technically.
REFERENCES Prosthodontic treatment for edentulous
patients- 13th edition by ZARB,HOBKIRK,ECKERT,JACOB
Clinical dental prosthetics-FENN & GIMSON’S
GAHAN, M. J. & WALMSLEY, A. D. 2005. The neutral zone impression revisited. British dental journal, 198, 269-272
http://www.slideshare.net/eugeneyeoh1/piezograph-2
http://www.jaypeejournals.com/eJournals/ShowText.aspx?ID=3376&Type=FREE&TYP=TOP&IN=_eJournals/images/JPLOGO.gif&IID=261&isPDF=NO
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081261/
F L O B R U S H I S N T S M I L E E E T H A N K Y O U
H