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1. The Ovate Pontic Design:
A Histologic Observation in
Humans
INDIAN DENTALACADEMY
Leader in continuing Dental Education
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2. Contents
• Introduction
• Review of literature
• Materials and methods
• Histometric and morphometric analysis
• Results
• Discussion
• Conclusion
• References
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3. • Introduction
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4. Review of literature
1. Herbert R Boyd (1955) compiled information regarding
the various types of pontics available and discussed in
brief the indications of their use.He stated that no pontic
can be considered to be absolutely ideal and we should
strive to select the one that fulfills the greatest number of
requirements for health,strength,function and esthetics.
2. R.Sheldon Stein (1966) studied the frequency and nature
of tissue reactions of underlying residual ridge mucosa to
specific pontic designs in 50 patients .He also compared
the frequency and nature of the reactions to various
materials used in pontic construction.He found that upon
removal of pontics ,inflammatory reaction was present
in 95% of the pontics.Microscopically there was a
predominance of inflammatory elements along with
alterations in the keratinized layer.www.indiandentalacademy.com

5. He concluded that the “modified ridge lap” was the ideal
design for the posterior region and the “lap facing” for the
anterior region.He found no distinguishing advantage with
porcelain ,acrylic resin or gold was used as pontic
material.
3. Joseph A .Clayton and Edward Greene (1970)compared
the surface roughness, following finishing and polishing of
pontics constructed from cast gold, acrylic resin and
glazed porcelain. He found that the surface of glazed
porcelain was significantly rougher than the polished
surfaces of acrylic resin and cast gold pontics.He however
stated that there was no tendency towards diminished
plaque formation and retention with any one of these
pontic materials.
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6. 4. Tim J.Dylian (1999) advocated the use of an ovate
pontic and described a method for communicating
exact dimensions for an ovate pontic form to the
dental labroratory using a polyvinyl siloxane putty as
matrix material.
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7. Materials and methods
• No of patients: 12 (4 men and 8 women)
• Age: Mean age 54 years
(range 36-66 yrs)
• Criteria of selection
1.Patients in good general health,did not use any
medication,did not smoke and had no history of advanced
periodontal disease.
2.Had 1 or 2 teeth missing in the maxillary premolar or molar
region and required replacement with either a screw
retained implant prosthesis or a temporarily cemented
provisional tooth-supported FPD.
3.No soft or hard tissue grafting performed in the prospective
pontic site.
4.Good oral hygiene status of the dentition on presentation
with a minimum of 85% on the hygiene index.www.indiandentalacademy.com

8. • 6 patients received screw- retained FPD implant prosthesis
veneered with glazed porcelain.
6 patients underwent restoration with FPDs veneered with
polished resin.
• During try-in of the restoration, a tight but non
compressive contact between the soft tissue and the pontic
was established by the use of a pressure indicator paste.
• After placement of the prosthetic restoration, patients were
instructed to use superfloss once a day in the pontic area.
They were recalled after 1,3,6 and 12 months to examine
the hygiene status of the dentition and when indicated to
reinforce oral hygiene measures.
• After the 12 month recall,the restorations were removed
and the soft tissue at the pontic sites were clinically
examined by use of a modification of the gingiva index.www.indiandentalacademy.com

9. Characteristics of subjects and biopsy sites at 12
month interval
Pt
no
Age Pontic site in
maxilla
Hygiene
index %
Gingiva
index
Veneering
material
1 62 Lt 1st
molar 85 0 P
2 54 Rt 1st
molar 95 0 P
3 52 Lt 1st
molar 96 0 P
4 47 Lt 2nd
premolar 90 0 A
5 46 Rt 1st premolar 92 1 A
6 62 Lt 1st
premolar 86 0 P
7 58 Rt 2nd
premolar 90 0 Awww.indiandentalacademy.com

10. Pt
no
Age Pontic site in
maxilla
Hygiene
index
Gingiva
index
Veneering
material
8 66 Lt 2nd
molar 87 0 P
9 62 Rt 1st
premolar 92 0 A
10 42 Lt 2nd
premolar 85 1 A
11 36 Rt 1st
premolar 87 1 P
12 61 Rt 1st
molar 93 0 A
M 54 89.8 0.25
SD 9.47 3.83 0.45
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11. • Soft tissue biopsy specimens were harvested
from the mucosa in contact with the pontic
area (test site) and from a reference area of the
mucosa outside the of restoration(control
sites).
• The sections were stained with periodic acid-
Schiff method and toluidene blue.
• Three randomly selected central sections from
each pontic and controlled site were used for
histologic analysis.
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12. Histometric and morphometric analysis
• The histologic assessments were carried out under
a Leitz DM-RBE microscope equipped with an
image system.
• The thickness of the epithelium and height of the
rete pegs were measured in mm and the thickness
of the keratin layer was measured in microns.
• The morphometric measurements were confined to
different zones:
Zone A : a 200 micrometer wide area immediately
subjacent to the epithelium
Zone B : a 200 micrometer wide central portion
below Zone A www.indiandentalacademy.com

13. • In Zones A and B the relative proportions
occupied by collagen, fibroblasts, vascular
structures, inflammatory cells and residual tissue
were determined.
• A grid (0.2 x 0.2 mm) comprising of 100 points
was superimposed over the area under
investigation.
• 4 grids were randomly distributed over each
connective tissue zone and mean values were
calculated for Zone A and Zone B in each
section. www.indiandentalacademy.com

14. www.indiandentalacademy.com

15. Results
• Results from histometric analysis
Pontic site Control site P value
(n=12)
Thickness of
mucosa
2.48 (0.75) 2.38 (0.50) .530
Thickness of
epithelium
0.40 (0.12) 0.43 (0.11) .182
Height of
connective
tissue papilla
0.24 (0.09) 0.28 (0.05) .197
Thickness of
keratin layer
8.16 (3.88) 21.53 (4.07) .002*
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16. Results of morphometric analysis
Connective tissue fraction (%)
Pontic site Control site P value(n=12)
Collagen 72.9(7.3) 76.4(3.0) .071
Fibroblasts 4.6(0.86) 4.8(1.1) .346
Vascular
structures
5.0(1.4) 6.2(6.2) .034*
Inflammatory
cells
4.3(3.8) 1.6(1.6) .004*
Residual tissue 13.1(2.6) 10.9(1.8) .011*
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18. www.indiandentalacademy.com

19. Results of morphometric analysis in Zone A and Zone B
Pontic site Zone A Zone B
Collagen 68.7 (12.0) 77.2( 3.2)
Fibroblasts 4.3 ( 0.9) 4.9( 0.9)
Vascular structures 5.2 ( 1.6) 4.9( 1.6)
Inflammatory cells 6.9 ( 7.1) 1.7( 0.8)
Residual tissue 15.0 ( 4.4) 11.3 (1.3)
Control site
Collagen 75.3 (3.4) 77.5( 3.1)
Fibroblasts 4.9 ( 1.1) 4.8( 1.0)
Vascular structures 6.4 ( 1.3) 6.0( 1.6)
Inflammatory cells 1.9 ( 0.8) 1.3( 0.6)
Residual tissue 11.5 ( 2.1) 10.4( 1.7)www.indiandentalacademy.com

20. • Thus the results indicate
1. The keratin layer was significantly thinner in the
test sites as compared to the control sites.
2. In test sites (subjects 2,3,5,10,11 and
12)remaining nuclei in the cells of stratum
corneum were observed. (parakeratinization)
3. The residual sites(1,4,6,7,8 and 9)and all control
sites were orthokeratinized.
4. The proportion of inflammatory cells was
significantly larger in test sites than in control
sites. www.indiandentalacademy.com

21. 5. When the connective tissue composition in
Zone A and Zone B of test sites was compared
it was observed that Zone A had a significantly
smaller proportion of collagen but larger
volumes of inflammatory cells and residual
tissue as compared with Zone B.
6. In control sites Zone A harbored larger tissue
fractions of inflammatory cells and residual
tissue as compared with Zone B.
7. No significant differences were observed
between test and control sites with regard to
composition of Zone B.
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22. • DISCUSSIONwww.indiandentalacademy.com

23. • CONCLUSION
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24. REFRENCES
• Herbert R Boyd :Pontics in fixed partial dentures. J
Prosthet Dent 1955;5:55-64
• R Sheldon Stein :Pontic residual ridge relationship: A
research report.J Prosthet Dent 1966;16:251-285
• Joseph A Clayton and Edward Greene : Roughness of
pontic material and dental plaque. J Prosthet Dent
1970;23:407-411
• Tim J Dylina :Contour determination for ovate pontics.
J Prosthet Dent 1999;82:136-142
• Contemporary fixed prosthodontics, Rosensteil ,3rd
edition
• Fundamentals of fixed prosthodontics, Shillenburg, 3rd
edition www.indiandentalacademy.com