Presentation1 support for complete denture

support for complete denture fabrication

1. 1 SUPPORT IN COMPLETE DENTURE PROSTHESIS Presented by ------------------------------------------------------- Dr PRATIK HODAR (Pg 1st yr) Guided by - Dr P. Balaji Raman Dr SashiPurna Dr Durga raju Dr Ashwin Aidasani Dr Abhay Narayane DR. HSRSM DENTAL COLLEGE AND HOSPITAL, HINGOLI DEPARTMENT OF PROSTHODONTICS

2. CONTENT Introduction Definition Types Importance Anatomical consideration Oral mucous membrane Denture supporting area Factors affecting support Conclusion Refrence 2

3. INTRODUCTION Dentist must base their technique on understanding of the biological aspect of the relationship between the denture base and supporting tissue. 3

4. DEFINITION THE FOUNDATION AREA ON WHICH A DENTAL PROSTHESIS RESTS.(GPT 8 TH EDITION) SUPPORT IS THAT QUALITY WHICH RESISTS VERTICAL MOVEMENT OR DISPLACEMENT OF THE DENTURE TOWARD THE BASAL SEAT. 4

5. Types Initial support – Through impression procedures Functional loading of supporting tissues Long term Directing occlusal forces towards resistant tissues 5

6. Reduce tissue ward movement of denture. Improve masticatory function. Maintain occlusal relationship . 6 IMPORTANCE:-

7. ANATOMICAL CONSIDERATION Oral mucous membrane: Definition. Classification . Importance for support. Denture supporting areas: Maxillarysupporting area. Mandibular supporting area. Anatomical landmarks. Bone. 7

8. ORAL MUCOUS MEMBRANE The oral cavity is lined by soft tissue known as mucous membrane. Mucous membrane composed of 2 layers, MUCOSA : It is made of stratified squamous epithelium & Connective tissue called Lamina Propria . SUBMUCOSA : It is formed by connective tissue. It may contain glands , fatty tisue , muscle, transmitting blood vessels and nerve. 8

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10. 10 (Courtesy : Orban’s : text book of oral histology 14 th edition)

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12. MASTICATORY MUCOSA COVERS :- Crest of the ridge, hard palate and the residual attached gingiva to the supporting bone. It has well defined keratinized layer. Submucosa is not well developed in masticatory Mucosa. 12

13. SPECIALIZED MUCOSA COVERS :- Dorsal surface of tongue. Keratinized in nature . 13

14. LINING MUCOSA COVERS :- Vestibular spaces, alveolingual sulcus , soft palate, ventral surface of tongue, unattached gingiva found on slopes of residual ridge . 14

15. IMPORTANCE FOR SUPPORT Gives cushioning effect Medium thickness and uniform resiliency favors prognosis. Thick mucous membrane- retention is compromised more than stability Thin and atrophic membrane gets damaged and ulcerated. Inflamed mucosa : Before denture insertion- elimination and treat for inflammation After denture insertion- ask patient to stop wearing denture 5-6 days till it gets normal. 15

16. REVIEW OF LITERATURE Yemm in 1972 -Stress can induce increase activity of masseter and temporalis muscles in denture wearers, which in turn cause tooth contact and eventually soreness of the mucosal tissues. Lindan in 1961 -0.13 gm/ mm 2 will displace soft tissues by 95% 16

17. SUPPOPRTING AREA OF THE DENTURE FOUNDATION 17

18. Maxillary Primary stress bearing areas Hard palate Maxillary tuberosity Secondary stress bearing area Residual alveolar ridge Rugae 18 (Courtesy : Zarb , Hobkirk : text book of prosthodontic treatment for edentulous patient 13 th edition)

19. HARD PALATE 19

20. Use for maxillary denture support. 20

21. MAXILLARY TUBEROSITY Large Tuberosity - provides fine bearing surfaces. But, have problems also – Encroachment on the inter-ridge distance; large or opposing undercuts Fibrous Tuberosity - Surgically reduced. 21

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23. RUGAE They are raised area of dense connective tissue radiating from the median suture in anterior 1/3 rd of palate Resists anterior displacement of denture 23

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27. MANDIBULAR primary stress bearing areas Buccal shelf Retro molar pad Secondary Residual alveolar ridge (Courtesy : Zarb , Hobkirk : text book of prosthodontic treatment for edentulous patient 13 th edition) 27

28. BUCCAL SHELF AREA Borders: Externally - external oblique lines Internally - residual ridge Anterior - buccal frenum Posteriorly - retro molar pad Parallel to the floor Forces directed right angle Very dense trabeculation 28

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30. RETROMOLAR PAD Pear shape One constant and unchanged structure Mass of soft structure Contain : mucous gland, temporal tendon, pterygomandibular raphae , buccinator , superior constricting muscle. 30

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34. RESIDUAL RIDGE For maxilla: abundant keratinized attached tissue. Square shaped arch, moderate palatal vault, absence of undercut, well defines hamular notch For mandible: well defined retromolar pad blunt mylohyoid ridge low frenum attachment. Problem with ridge Sharp and spiny Crestal bone irregularities Sever resoption and mental foramina Tori 34

35. Sharp ridge 35

36. Mental forameia 36

37. tori 37

38. RESIDUAL RIDGE RESORPTION “My gums have been shrunken” SIX ORDERS OF MANDIBULAR ANTERIOR RESIDUAL RIDGE FORM by Attwood (1963)- Order I-Pre extraction. Order II-Post extraction. Order III- High, well rounded. Order IV-Knife edge. Order V- Low, well rounded. Order VI- depressed. 38

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40. Consequences: ----Compromised support -Movement of dentures -Instability of prosthesis Prevention -Minimizing the forces transmitted to supporting tissues -Decrease the movement of prosthesis 40

41. 41 ( Lekholm & zarb 1985 )

42. EFFECT OF PRESSURE ON BONE RESORPTION Gordan GS Genent HK after the age of 40xyrs, the skeleton decreases, so that by age of 65 approximately 1/3 rd of bone minerals are lost. SOBOLIK(1960)writes that constant pressure will cause bone resorption , but intermittent pressure favours bone formation. PENDLETION(1951)has said that pressure applied to bone in an abnormal direction will result in resorption . 42 REVIEW OF LITERATURE

43. STAHL(1948) showed that ridge resorption increase with the severity of diabetes. PERSON(1957) noted that during a rapid and intense loss of alveolar bone in diabetic, the long bone and pelvis remained intact. NORDIN(1960) Osteoporosis is generalized condition of bone in which the volume of bone in skeleton is reduced. 43

44. BONE 44

45. CLASSIFICATION 45 ACCORDING TO HISTOLOGY (Courtesy : Orban’s text book of oral histology 13 th edition)

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47. BONE HISTOLOGY Bone cells- A. Osteoblasts , B. Osteocytes , C. Osteoclasts D.Stem cells or Osteochondral Progenitor cells Woven bone – Collagen fibers randomly oriented. Lamellar bone- Mature bone in sheets. Compact bone- Trabaeculae . Cortical bone- Dense. 47

48. It is in continuous flux throughout life. (Frost ; enlow ) ADULTS : Formation= Resorption SENILITY : Formation< Resorption Placement of denture after extraction require 6 weeks/ 2 months . 48

49. WOLF LAW- Change in form follows a change in function owing alteration of the internal architecture and external conformation of bone. NEUFELD REPORTED: In some specimens studied, the trabecular pattern was arranged in such a way that it indicated that there was some adaptation of structure of bone to the bone to presence of an appliance in region near the superior space of alveolar process. 49

50. FACTORS THAT INFLUENCE THE FORM AND SIZE OF SUPPORTING BONE 1] Its original size and consistency; 2] the persons general health; 3] forces developed by the surrounding musculature; 4] the severity the location of periodontal disease ( Hausman ; Hedegard ) 5] forces accruing from the wearing of dental prosthesis; 6] surgery at the time of removal of the tooth; 7] the relative length of the time different parts of the jaws has been edentulous. 50

51. Include:- all denture bearing area. Exclude:- all relief area. Snow shoe effect Watt 1961 -mean denture bearing area maxilla (22.96 cm 2 ) mandible (12.25 cm 2 ) 51

52. FACTORS AFFECTING SUPPORT Large surface area Nature of supporting area Impression procedure Accuracy of fit Direct bone anchorage 52

53. 1] Recording the tissue impression at their rest position. 2] Decreasing the size of food table. 3] Developing an occlusion that eliminates, as much as possible, horizontal forces and those that produce torque. 4] Extending the denture base for maximum coverage within physiologic limit. 5] Biting with the knife and fork, that is, placing small masses of food over the posterior tooth where the supporting bone is best suited to resist force. 6] Removing the denture for at least 8 of every 24 hours for tissue to rest. TAKE AWAY MESSAGE 53

54. CONCLUSION Selection of regions that should provide primary and secondary support depends on anatomic variation unique to each patient. 54

55. REFERENCE Orbans : Oral histology and embryology 14 th edition Charles heartwell : syallabus of complet denture 4 th edition. Jhon sharry : Complet denture prosthodontic 3 rd edition. Zarb and Bolender : prosthodontic treatment for edentulos patient 12 th edition. Zarb and Bolender : prosthodontic treatment for edentulos patient 13 th edition. 55

56. Sheldon wrinkler : essentials of complete denture prosthodontics 3 rd edition. Karl mish : Contemporary implant dentistry 3 rd edition. Glossary of prosthodontics terms 8 th edition. A contemporary review of the factors involved in complete dentures Part III: Support T. E. Jacobson & A. J. Krol JPD 1983;49:306-313. A review of residual ridge resorption and bone density: Esa klemetti 56

57. 57 THANK YOU