This document summarizes the key points of the classic article "The Neutral zone in complete dentures" by Beresin and Schiesser. It describes the neutral zone as the area in the mouth where the forces of the tongue pressing outwards are balanced by the forces of the cheeks and lips pressing inwards. It discusses how using the neutral zone technique in denture construction can lead to improved stability, retention and aesthetics by properly accounting for muscular forces. The technique involves making external impressions of the lips, cheeks and tongue to capture muscle function and determine the contours of the denture.

1. The Neutral zone in complete
dentures
JOURNAL CLUB
PRESENTED BY – DR. VAISHALI SHRIVASTAVA
1ST YEAR POST GRADUATE STUDENT
DEPT. OF PROSTHODONTICS, CROWN & BRIDGE
AND IMPLANTOLOGY
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2. TITLE- The Neutral zone in complete
dentures
GENRE-CLASSIC ARTICLE
SOURCE
Beresin VE, Schiesser FJ. The neutral zone in complete dentures. The
Journal of prosthetic dentistry. 1976 Oct 1;36(4):356-67.
AUTHORS
Victor E. Beresin,
Frank J. Schiesser
Temple University School of Dentistry, Philadelphia
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3. INTRODUCTION
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4. 1) The potential space between the lips and cheeks on one side and the tongue on the other;
that area or position where the forces between the tongue and cheeks or lips are equal
(GPT9)
2) The neutral zone has been defined as the area in the mouth where during function,the
forces of the tongue pressing outwards are neutralised by the forces of cheeks and lips
pressing inwards – Beresin & Schiesser
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5. Muscle force in the dental arch
• muscular activity and habits which develop during childhood continue through life.
• It is therefore, extremely important that the teeth be placed in the mouth with the arch
form located so that it will fall within the area compatible with muscular forces.
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6. Denture surfaces
surfaces
• Occlusal
surface
Occlusal
surface
• Impression
surface
Impression
surface
• Polished
surface
SIR WILFORD FISH
external or polished surface of the denture is in contact with the cheeks, lips, and
tongue
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7. Influence of forces on denture surfaces
RIDGE LOSS
DENTURE BASE
AREA
Impression surface
Polished
surface
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8. (From Beresin VE, Schiesser FJ. The neutral zone in complete dentures. St. Louis: C. V. Mosby Co; 1973.
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9. (From Beresin VE, Schiesser FJ. The neutral zone in complete dentures. St. Louis: C. V. Mosby Co; 1973.
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10. (From Beresin VE, Schiesser FJ. The neutral zone in complete dentures. St. Louis: C. V. Mosby Co; 1973.
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11. (From Beresin VE, Schiesser FJ. The neutral zone in complete dentures. St. Louis: C. V. Mosby Co; 1973.
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13. Reversed Sequence in Denture
Construction
Primary impression
Trays
Final impression
Record base and rims
Jaw relation
Try in
Denture deliver
Trays
Occlusal rims
(impression
compound)
Final impression (
close mouth)
Normal
CD
Neutral
zone
CD
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14. 14

15. Base and Body of denture
Impression surface
Polished surface
base
Body
By separating these two entities, the dentist can more readily determine and correct the cause of
instability of the denture.
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16. External Impression
the neutral-zone procedure, the external contours are molded by muscle function
By means of these external impressions, a physiologic molding is done so that the external surfaces are
functionally compatible with muscle action
External impressions, similar to secondary impressions of the ridge, capture in greater detail the action of
the lips, cheeks, and tongue and determine the thickness, contours, and shape of the polished surface of
the denture
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17. (A) Labiobuccal impression on lower trial denture. Note the narrowing in the bicuspid area created by
muscle function. (B) and (C) External lingual lower impression. Note the ledge formed by the tongue
during swallowing. (From Beresin VE, Schiesser FJ. The neutral zone in complete dentures. St. Louis: C.
V. Mosby Co; 1973.)
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18. Understandable
schematic dig
Denture construction
is not well explained
muscles which are
involve are not
explained
FINDINGS
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19. RELATED ARTICLES
Gahan MJ, Walmsley AD. The neutral zone impression
revisited. British dental journal. 2005 Mar;198(5):269-72.
The neutral zone impression revisited
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20. A denture shaped by the neutral zone (NZ) technique will ensure that the
muscular forces are working more effectively and in harmony. The dentures
will have other advantages:
• Improved stability and retention
• Posterior teeth will be correctly positioned allowing sufficient tongue
space
• Good aesthetics due to facial support.
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21. BUCCINATOR TONGUE
MODIOLUS
ORBICULARIS ORIS,
MENTALIS
MAJOR
MUSCLES
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22. The role of the buccinator during function is to position food on the occlusal surfaces of the teeth. This
action is coordinated with the tongue to maintain the food in this position.
BUCCINATOR
In the highly atrophic, mandible positioning of the anterior teeth can be problematic. The NZ technique
provides the correct tooth position to allow for the balancing of these muscular forces during function.
ORBICULARIS ORIS, MENTALIS
TONGUE
The tongue is a powerful group of muscles and it is in constant contact with the denture at rest and
during function.
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23. The modiolus determines the position of the premolar teeth and the shape of the polished surface in that region. This
produces a narrowing of the denture so that the polished surface does not hinder the movements of the modiolus
during function
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27. The aim of the neutral zone is to construct a denture in
muscle balance, as muscular control will be the main
stabilizing and retentive factor during function. The
technique is relatively simple but there are increased
chair time and laboratory costs
CONCLUSION
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28. THANKYOU
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