1. ACKNOWLEDGEMENT
dr shabeel pn
We express our deep and sincere gratitude to whom who has been our inspiration for this presentation.

2. DEFINITION
Border molding is the shaping of an impression material by the manipulation or action of tissues adjacent to the borders of an impression tray

3. OBJECTIVE
To determine the contour, height and width of the borders of the complete denture

4. ANATOMICAL LANDMARKS Limiting structures:- Labial frenum
Labial vestibule
Buccal frenum
Buccal vestibule
Vibrating line

5. CUSTOM TRAY FABRICATION
Preliminary impression is taken using stock trays
Primary cast is obtained with this impression
Wax spacer used, if required
Custom tray is fabricated (stepped handle for maxillary arch)

6. MATERIALS USED FOR BORDER MOLDING
GREEN STICK COMPOUND
ELASTOMERIC IMPRESSION MATERIALS (POLYETHER)

7. BORDER MOLDING TECHNIQUE
GREEN STICK COMPOUND - SECTION WISE TECHNIQUE
POLY ETHER - SINGLE STEP TECHNIQUE

8. FINAL PROCEDURES FINAL ADJUSTMENTS OF REFINED TRAY
PERFORATION OF THE TRAY

10. ANATOMICAL LANDMARKS

11. FACIAL MUSCLES

12. ORBICULARIS ORIS – Oral Sphincter
ORIGIN
Medial maxilla and mandible
Deep surface of perioral skin
Angle of mouth (modiolus)
INSERTION
Mucous membrane of lip
ACTION
Contraction of the muscle protrudes lip or resists distension

13. BUCCINATOR - Cheek muscle
ORIGIN
Alveolar process of maxilla and mandible
Pterygomandibular raphae
INSERTION
Angle of mouth (Modiolus)
Orbicularis oris
ACTION
Presses cheek against molar teeth with tongue
Helps to keep food material between occlusal surface and out of the oral vestibule
Resists distension (while blowing)

14. LEVATOR ANGULI ORIS ORIGIN Infraorbital maxilla (Canine Fossa)
INSERTION
Angle of mouth (Modiolus)
ACTION
Dilator of mouth
Elevate labial commissure - Bilaterally while smiling
Unilaterally while sneering

15. MUSCLES WITH ATTACHMENT TO THE MODIOLUS
BUCCINATOR
ZYGOMATICUS MAJOR
LEVATOR ANGULI ORIS
RISORIUS
DEPRESSOR ANGULI ORIS

16. MUSCLE ORIGINATING FROM THE MODIOLUS
ORBICULARIS ORIS
SPINTURE MUSCLE OF THE ORAL FISSURE

17. DIALATOR MUSCLES OF THE MOUTH
LEVATOR LABII SUPERIORES
LEVATOR ANGULI ORIS
ZYGIOMATICUS MAJOR
ZYGOMATICUS MINOR
DEPRESSOR LABII INFERIORIS
DEPRESSOR ANGULI ORIS
RISORIUS

18. PALATE

24. MUSCLES OF PALATE LEVATOR VELI PALATINI TENSOR VELI PALATINI
PALATOGLOSSUS
PALATOPHARYNGEUS
MUSCULUS UVULAE

25. TENSOR VELI PALATINI SUPERIOR ATACHMENT
Scaphoid fossa of medial pterygoid plate
Spine of sphenoid bone
Cartilage of pharyngo tympanic tube
INFERIOR ATACHMENT
Palatine aponeurosis
ACTION
Tenses soft palate
Opens mouth of pharyngotympanic tube during swallowing and yarning

26. LEVATOR VELI PALATINI SUPERIOR ATTACHMENT
Cartilage of pharyngotympanic tube
Petrous temporal bone
INFERIOR ATTACHMENT
Palatine aponeurosis
ACTION
Elevates soft palate during swallowing and yarning

27. PALATOGLOSSUS SUPERIOR ATTACHMENT Palatine aponeurosis
INFERIOR ATTACHMENT
Side of tongue
ACTION
Elevates posterior part of tongue and draws soft palate into tongue

28. PALATOPHARYNGEUS SUPERIOR ATTACHMENT
Hard palate and palatine aponeurosis
INFERIOR ATTACHMENT
Lateral wall of pharynx
ACTION
Tenses soft palate and pulls walls of pharynx superiorly, anteriorly and medially during swallowing

29. MUSCULUS UVULAE SUPERIOR ATTACHMENT
Posterior nasal spine and palatine aponeurosis
INFERIOR ATTACHMENT
Mucosa of uvula
ACTION
Shortens uvula and pulls it superiorly

30. LIMITING STRUCTURES OF EDENTULOUS MAXILLARY ARCH
LABIAL FRENUM
BUCCAL FRENUM
LABIAL VESTIBULE
BUCCAL VESTIBULE
HAMULAR NOTCH
VIBRATING LINE

31. LABIAL FRENUM It is a fold of mucous membrane at the median line.
It starts superiorly in a fan shape and
converges as it descends to its terminal attachment on the labial side of the ridge.
It contains no muscles and has no action of its own.

32. LABIAL NOTCH SIGNIFICANCE
Corresponding area of labial frenum on the final impression
SIGNIFICANCE
The labial notch of the labial flange of denture must be wide and deep enough to allow the frenum through it without manipulation of the lip.

33. BUCCDAL FRENUM RELATION WITH FACIAL MUSCLES SIGNIFICANCE
It forms the dividing line between labial vestibule and buccal vestibule
It is formed by mucous membrane
Can be a single fold, double fold and even fan shaped
RELATION WITH FACIAL MUSCLES
Levator Anguli Oris muscle attaches beneath the frenum
Orbicularis oris pulls the frenum forward
Buccinator pulls the frenum backward
SIGNIFICANCE
It requires more clearance in the denture base for its movements than the labial frenum

34. BUCCAL NOTCH SIGNIFICANCE
It is the impression made by the buccal frenum on the impression
It should be wide and deep enough to permit the movements of the buccal frenum
SIGNIFICANCE
While making impression, lips should be moved forward and backward by the dentist to allow the free movement of the buccal frenum in the buccal notch

35. LABIAL VESTIBULE RELATION WTH FACIAL MUSCLES
Labial vestibule is divided into left and right labial vestibule by the labial frenum
Mucosa is thin and NONKERATINIZED
Submucosa is thick and contains large amount of areolar tissue and elastic fibers
Lamina propria is elastic in nature
RELATION WTH FACIAL MUSCLES
Orbicularis oris is the main muscle which forms the outer surface of the labial vestibule
The fibers of this muscle runs horizontally through the lips to anastamose with the muscles of the Buccinator

36. BUCCAL VESTIBULE
It is the space distal to the buccal frenum till the hamular notch
It is bound externally by the cheek and internally by the residual ridge
Mucous membrane covering is similar to labial vestibule
The size of the vestibule varies with
contraction of the Buccinator M.
position of the mandible
amount of bone lost by resorption from the maxilla

37. HAMULAR NOTCH
Region between the tuberosity of the maxilla and the hamulus of the medial pterygoid plate
SIGNIFICANCE
Posterior palatal seal is placed through the centre of the deepest part of hamular notch
Forms the posterior boundary for the denture base
If the posterior border extend further in this region, the denture base will compress the pterygoid hamulus and obstruct the action of the pterygomandibular raphae

38. VIBRATING LINE
It is the imaginary line drawn across the palate that marks the beginning of motion of the soft palate when patient is asked to exhale through his/her nose with the nostrils closed
Extends from one hamular notch to the other
Lies distal to the junction of the hard and soft palate – lies always on the soft palate
At the midline, it passes about 2mm in front of the FOVEA PALATINAE (indentations near the midline of the palate formed by a coalescence of several mucous gland ducts)
It is not a well defined line – but an area
Submucosa in this region contains glandular tissue

39. SIGNIFICANCE
It is an ideal guide for locating the posterior palatal seat area (the distal palatal termination of the denture) during BORDER MOLDING
The distal end of the maxillary denture should extend at least to the vibrating line (in most cases 1 to 2 mm posterior to the vibrating line)

41. FINAL IMPRESSION
After the primary impression is taken and a cast made from it, the procedure for final impression begins
A carefully made special tray is trimmed at the corners and border molding is done followed by a wash impression and pouring in the cast completes the procedure. In a nutshell, final impression involves special tray preparation and wash impression

42. MATERIALS Metallic Oxide Impression Paste (Ex. ZOE Impression Paste)
Elastomeric Impression Materials

43. ZINC OXIDE EUGENOL IMPRESSION PASTE
INDICATIONS
These pastes are rigid when set and can be used only when there is no bony undercuts
Used in a close fitting tray and so the overall bulk of impression is kept to a minimum. This is useful where the denture bearing area is reduced due to bone resorption
CONTRAINDICATIONS
Not used in patients with dry mouths because the paste tends to adhere to the oral mucous membrane
When the patient is intolerant to Eugenol as it can cause a burning sensation in some individuals

44. ELASTOMERIC IMPRESSION MATERIALS
These materials are used in spaced custom trays to avoid displacement the border tissues
A less viscous consistency/body of the irreversible hydrocolloid is used for making final impression compared with that used for preliminary impression.

46. CUSTOM TRAY FABRICATION
DEFINITION
A special tray is defined as a custom made device prepared for a particular patient which is used top carry, confine and control an impression material while making an impression.
FUNCTION
To provide better retention of denture
To take secondary or wash impression

47. IDEAL REQUIREMENTS
Should be rigid, well adapted and dimensionally stable on primary cast
Should be easy to manipulate and remove
Should not flow or warp
Should not react with impression material
Should be free of voids or projections
Should be at least 2 mm thick in the palatal area for adequate rigidity
Should be smooth lest it injures the soft tissue inside the mouth
Should be trimmable with bur

48. Should be simple, taking minimum amount of time and should be prepared at a reasonable cost
Should have 2 mm relief near the sulcus so that the green stick compound can be used to do border molding
Should retain its shape while loading of impression
Should have contrasting colour to make its margins prominent when placed in mouth

49. CONDITIONING THE PRIMARY CAST
Primary impression has overextended borders therefore special tray should be 2 to 4 mm short of the sulcus
A line is drawn across the posterior border connecting the 2 hamular notches (this line is parallel to fovea palatinus)
A line is drawn outlining the muco-buccal fold above the frenum attachments
All trays should be checked of displacement in the mouth

50. ADAPTING THE WAX SPACER
Base plate wax, 1 mm thick approximately is placed on the cast within the outline border to provide space in the tray for the final impression material
Spacer should be cut out in 2 to 4 places so that the special tray touches the ridge in these areas. This is done to stabilize the tray during impression making.
The posterior palatal seal area on the cast is not covered with the wax spacer therefore the completed custom tray will contact the mucous membrane across the posterior palatal border

51. APPLICATION OF SEPARATING MEDIUM
To prevent special tray from binding to the cast
FABRICATION OF CUSTOM TRAY HANDLE
The custom tray should be 2 to 3 mm thick, with a stepped handle in the anterior region of the tray to facilitate removal from the mouth
The step should be of sufficient height to avoid distortion of the upper lip when the tray is in the mouth

52. TRIMMING THE CUSTOM TRAY

54. IDEAL REQUIREMENTS OF MATERIALS USED FOR BORDER MOLDING
It should have a sufficient body to allow to remain positioned on the borders during loading of the tray
Allow some pre shaping of the form of the borders without adhering to the finger
Have a setting time of 3 to 5 minutes
Retain adequate flow while tray is seated in the mouth
Allow finger placement of the material into the deficient parts after tray is seated
Should not cause excessive displacement of the vestibule
Readily trimmed and shaped so excess material can be removed and borders are shaped before final impression is made

55. GREEN STICK IMPRESSION COMPOUND
Rigid impression Material
MANIPULATION
On heating above fusion temperature over a flame, the material becomes ready for border molding
Over heating is avoided as it can volatilize the plasticizer
Tempering is done using a water bath which reduces the temperature to tolerable limits
The compound becomes rigid at oral temperature

57. POLYETHER ELASTOMERIC IMPRESSION MATERIAL
Introduced in Germany in late 1960
It is a polyether based polymer

58. Available in 3 viscosities –
MODE OF SUPPLY
Base and catalyst in paste form
Available in 3 viscosities –
Light body
Medium body
Heavy body

59. COMPOSITION BASE PASTE ACCELERATOR PASTE Alkyl aromatic sulphonate
Polyether polymer
Colloidal silica (filler)
Glycoether/Phthalate (plasticizer)
ACCELERATOR PASTE
Alkyl aromatic sulphonate
(cross linking agent)
Colloidal silica (filler)
Glycoether/Pthalate (plasticizer)

60. SETTING REACTION
It is cured by a polymerization reaction between Aziridine rings at the end of the branched polyether molecule
The main chain is a copolymer of ethylene oxide and THF
Cross linking is by initiator called aromatic sulphonate ester with alkyl group
The reaction is exothermic

61. PROPERTIES Working time – 3 minutes Setting time – 6 minutes
No byproduct is formed during reaction
Shelf life – more than 2 years

62. BRAND NAMES
Impregum F
Permadyne
Polyjel

64. PROCEDURE FOR BORDER MOLDING
This is a stepwise procedure which ensures an optimal peripheral seal
Firstly, special tray is checked in the patient's mouth for its adaptability, extension and checked for irregularities if any that may hurt soft tissue while taking impression

65. Posterior palatal border - tray should include both hamular notch and extend 2 mm posterior to the vibrating line
Vibrating line can be demonstrated by
When patient says "ah"
When patient's nostril closed and asked to exhale through nose during which soft palate will flex at junction

66. Posterior border of tray marked with a marker, tray then place in mouth and patient asked to say "ah"
Tray removed and mark is transferred into the mouth which is compared with vibrating line and hamular notch

67. STEPS IN BORDER MOLDING
Procedure in which portions of the periphery of the tray are refined individually
 Greenstick compound is softened over flame and added along the labial vestibule initially
Material is tempered before placing intra-orally
Tray introduced into mouth with lip first elevated, then extended outward, downward and inward

68. Massage the upper lip in lateral motion
Patient instructed to pucker

69. Material is then softened and then placed over buccal vestibule and tempered
Tray is seated in oral cavity stabilizing with finger
At the buccal frenum, cheek is elevated, pulled outward, downward, inward and moved backward and forward to simulate movement of frenum
Posteriorly, buccal flange border molded by extending cheek outward, downward and inward followed by wide opening of mouth and side to side movement of mandible

70. Patient asked to pucker for activation of Buccinator
Greenstick is flamed, traced along border from buccal to hamular notch area across midline to corresponding area on opposite side
Next the posterior palatal area is recorded to complete an effective peripheral seal during which patient is asked to say "ah"

71. After border molding, molded section is immersed in cold water
Evaluate the retention and stability of the border molded tray

74. BORDER MOLDING USING POLYETHER IMPRESSION MATERIAL
Placement of adhesive on the border of the tray
Cutting away the wax spacer from the border to allow space for the impression material.
Placement of polyether material along the borders
Composition is in such a way that sufficient working time is to be provided
Material is pre shaped to proper contours

75. Placement of tray in the mouth
Lips retracted to avoid scraping of material from the borders
If insufficient material is present, transferring of excess material from the adjacent site

76. BORDER MOLDING IN THE ANTERIOR REGION
Lip elevated and extended out, downward and inward
IN THE BUCCAL FRENUM
Cheek is elevated and pulled outward, downward and inward and move backward and forward to stimulate the movement of frenum

77. POSTERIORLY -
Buccal flange is border molded by extending the cheek outward, downward and inward
Patient asked to open wide and move mandible side to side
When impression material is set tray removed from the mouth
Contour should be rounded and over extensions are readily detected as the tray will protrude through the polyether material

79. GREEN STICK COMPOIND ADVANTAGES Corrections can be made Less expensive
Less technique sensitive
No imbibition and synerisis
DISADVANTAGES
Poor surface detail
Time consuming procedure
More number of tray insertions
Discomfort to the patient

80. POLYETHER ELASTOMERIC IMPRESSION MATERIAL
ADVANTAGES
Fast setting
Good stability
Can delay pouring
No need for heating the material
Procedure is completed in one step
No byproducts are formed during setting
Shelf life of 2 years

81. DISADVANTAGE
Bitter taste
Stiff – high modulus of elasticity
Absorbs water
Leaches components
Corrections cannot be made
Expensive

83. FINAL PROCEDURES
After border molding, the tray should be prepared before making the secondary impression
Space should be created for final impression material
If necessary, the thickness of the border should be adjusted
Material that extend into the undercut is reduced
Finally, a small amount of material is removed from those parts of the border that have not already been adjusted

84. Approximately 0.5 mm is removed from the inner, outer and top surface of the border
Stick impression compound is adjusted with a scalpel
polyether adjusted with a scalpel or a bur
The material over the posterior area is not adjusted
Finally, holes can be placed in the palate of the impression tray with a medium sized round bur
Then the adhesive material is applied

85. The objective is to avoid recording denture bearing tissues in a displaced or distorted position
A number of materials are available for making the final impression and it includes metallic oxide impression paste, polyether and silicone impression materials and irreversible hydrocolloids.