Single Complete Denture

1. Single Complete Denture NiazAhammed A

2. Contents • Introduction • Problems in single complete denture • Diagnosis and treatment planning -mouth preperations -occlusal adjustments • Modifying occlusal pattern • Swenson’s method • Yurkstas • Bruce method • Boucher’s method

3. Achieving harmonious balance • Functional chew in • Articulator equilibriation • Mandibular denture opposing natural maxillary teeth • Maxillary denture opposing RPD • Maxillary denture opposing FPD • Maxillary denture opposing CD • Clinical procedures • Occlusal materials • Sequelae of single dentures • Combination syndrome

4. Introduction

5. A single complete denture can oppose any one of the following: • Natural teeth that are sufficient in number not to necessitate a fixed or removable partial denture. • A partially edentulous arch in which the missing teeth have been or will be replaced by a fixed partial denture. • A partially edentulous arch in which the missing teeth have been or will be replaced by a removable partial denture. • An existing complete denture.

6. Problems in single complete denture • High magnitude of forces that natural teeth can exert on denture base • Occlusal form of denture base-over eruption or tilting and high or sharp cusps

7. Diagnosis and treatment planning • Primary objective is to preserve the remaining structures • Factors to be considered are: -Acceptable interocclusal records -Stable jaw relationship with bilateral posterior teeth contacts -Forces directed along the long axis of the teeth -Avoidance of adverse tooth contacts Prosthetic treatment for edentulous patients; Zarb ,13thedition

8. Mouth preperation: • Arch form in dentate jaw may not co ordinate with the arrangement of denture teeth • The remaining teeth may be tilted or supra erupted • The natural teeth can be ground or restored to give a more suitable occluding surface and grossly malpositioned teeth can be extracted or orthodontically repositioned

9. Occlusal adjustments • Natural lower cuspids and incisors are long and often has to be ground • Severely tilted and overerupted molars should be considered for extraction • If tilt is not extreme, distal half of occlusal surface is ground flat and denture made to contact with that area only

10. Ideal treatment is to restore the tooth with cast gold crown or onlay • If there is a large edentulous space mesial to the molar, a bridge or removable denture should be inserted

11. Carl F. Driscoll and Radi M. Masri* proposed a classification system that could simplify the identification and treatment of single denture patients *DCNA, July 2004: Vol 48; No.3

12. Modifying Occlusal Pattern

13. Several techniques to modify the existing occlusal pattern prior to denture construction have been suggested: • Swenson’s technique • Yurkstas method • Bruce method • Boucher method • Han Kuang Tan’s technique

14. Swenson’s method (1964) Complete denture prosthodontics: Sharry, 315

15. Yurkstasmethod (1968) *DCNA, July 2004: Vol 48; No.3

17. The casts are mounted and the necessary modifications are made on the stone cast. • A clear acrylic resin template is fabricated on the modified stone cast. • The inner surface of template is coated with pressure indicating paste and the interferences are noted through template. • The desired modifications are done till the template seats properly. Bruce method Complete dentures opposing natural teeth: Bruce etal: JPD, November 1971

18. Boucher’s method

19. Han-Kuang Tan A preparation guide for modifying the mandibular teeth before making a maxillary single complete denture Han- Kuang- Tang, JPD, 1997

22. Achieving Harmonious Occlusal Balance

23. The various techniques fall in two categories Those which statistically equilibrate occlusion using a Articulator programmed to simulate patients jaw movements. Those which dynamically equilibrate occlusion using a Functionally Generated Path

24. Functionally Generated Chew-in Technique These techniques to provide the most accurate method of recording occlusal pattern. However, Contraindications: • The desired jaw movements and necessary record base stability are not possible • The denture space is inadequate. • Physical and mental condition of the patient seriously compromise effective cooperation.

25. Stansbury (1951) Suggested using compound maxillary rim for functionally generated chew-in technique. Single denture construction against non-modified natural dentition: JPD, November, 1951

27. Vig’s technique (Robert G. Vig 1961) • Preliminary impressions and base • Upper and lower impressions are made, casts poured and denture base fabricated with cold cure resin. • Registration and mounting • Centric relation at acceptable vertical dimension recorded • Anterior teeth are arranged • Preparing the chewing apparatus: • The wax occlusion rim posterior to cuspid is removed. • Resin in dough stage is placed on denture base and the articulator is closed to press the resin against the occlusal surface. • When set, the resin is trimmed so as to leave only a fin of resin in contact with the central grooves of lower posterior teeth. Modified chew in tech- RG Vigg, JPD, April 1964

28. Cusp and Sulcus analysis: • The patient is directed to make a lateral excursions to bring tips of the mandibular cusps in contact with the fin • If most of the teeth do not contact the fin on lateral excursions then the teeth in contact must be ground until an equal contacts occurs between the teeth and plastic. • If most of the buccal cusps contacts the maxillary fin, but few do not, the fin must be lengthened by deepening the central fossae of teeth and building the fin with cold cure resin. • Even contacts are achieved on both sides of arch. • Holes about 1/4th inch apart are drilled and filled with sticky wax. • The fin is then built up with wax according to the width of the opposing tooth.

30. Functional impression and Chew-in • Tissue conditioning resin is added to the impression side and base is seated in the mouth. • After ½ hour patient is given thin slice of fruits like banana and asked to chew normal pattern followed by vigorous chewing. • The chewing pattern and impression surface are examined. • If few areas expose : the resin is trimmed and relined • If borders are exposed : resin is trimmed and relined • If border unsupported : build with resin and reline • The wax on the occlusal surface is rebuilt and the base is inserted in patients mouth with instructions not to consume solid or hot foods and to wear base all night.

31. Forming the stone chew-in record • Master cast poured without boxing • Record is obtained for the waxed chew in • The cast, record base, chew-in record and counter cast are mounted on the articulator • Arranging the posterior teeth • The teeth are arranged according to the occlusal scheme of the mandibular teeth and all the interferences in the lateral excursive movements are removed with the help of the chew-in record.

32. Rationale of the technique • Creates cuspal harmony in the non-functional glides • Patients with limited motion, unusual patterns of masticatory movements, persistent bruxism and other atypical situations can be accommodated Contraindicated if the mucosa is so resilient that it can allow shifting of the record base during the chew-in phase.

33. Kenneth D. Rudd and Robert M. Morrow (1973) Occlusion and single denture; Rudd , Morrow; JPD July, 1973

35. Stone core: • The generated wax path is carefully boxed and stone is poured. • The upper denture teeth are set or ground to fit the generated path as recorded in the stone core.

36. Sharry(1968) • Mentions a simple technique of using maxillary rim of softened wax. • Lateral protrusive chewing movements are made so that the wax is abraded. • Generating functional path of the lower cusps. • This is continued until the correct vertical dimension has been established. Complete Denture Prosthodontics; Sharry 317

37. Articulator Equilibration Technique Indications: • The denture base lacks stability. • If the patient is physically unable to form a chew-in record. Essentials of complete denture prosthodontics 2nded, Sheldon Winkler, 421-24

39. The selection of the holding cusps depends according to the lower occlusal scheme

41. MandibularDenture to Oppose Natural Maxillary Teeth: • Seldom this condition does occur. • It usually happens as a result of surgical or accidental trauma. • An example of surgical trauma is the removal of the mandibular teeth for persons who have to undergo irradiation therapy for a tumor.

42. Complicating factors for the single mandibular complete denture opposing natural teeth 1.The denture supporting tissues for the mandibular complete denture is relatively small compared to the maxillary supporting tissue. 2.The mucosa with tightly attached submucosaoverlying the periostiumand bone of the lower residual ridge is thin. 3.For the above two reasons, the underlying bone is extremely prone to resorptionfrom occlusal forces of the natural teeth. 4. Impact of occlusal forces from moving mandible Heartwell; syllabus of complete dentures, 488-89; Zarb;12th edition

43. There are two situations When a mandibular complete denture, opposing upper natural teeth are accepted: 1.When the patient has a class III jaw relationship. This occur when the mandible is largerthan normal or the maxilla is smallerthan normal. 2.When the patient has a cleft palate,

44. Eugene tilman; removable partial upper and lower complete dentures( jpd,nov- dec, 1961) • A posterior occlusion employing nonanatomic teeth aids in the stability and reduces the displacing forces encountered in mandibular movements during mastication. • The lower anterior teeth must be arranged for esthetic appearance • A plane of occlusion is constructed on the lower base beginning at the height of the cusp of the lower cuspid and extending distally parallel with the crest of the lower ridge

45. Single Complete MaxillaryDenture to Oppose Natural MandibularTeeth The diagnostic procedures should determine that; • there are sufficient teeth in the mandibular arch, • periodontal health is acceptable, and • there are no missing teeth to be replaced. Syllabus of complete Dentures; Heartwell, pg- 490-92

46. Some times the positions of the mandibular anterior teeth will not allow the maxillary anterior teeth to be positioned in an esthetically acceptable manner or for balanced occlusion. This problem may be resolved as follows: 1. Reposition the natural teeth with orthodontic procedures. 2. Alter the clinical crowns of the teeth by grinding or with restorations. 3. Accept balanced occlusion with the jaws in centric relation and not in the eccentric positions.

47. The occlusal forms of the natural teeth usually act as the guide in selecting the occlusal form for the maxillary posterior teeth. • In most situations this would be a cusp tooth • But if the natural teeth are abraded and are not restored prior to treatment, the monoplane form may be the choice for the occlusal surfaces of posterior teeth. • When the mandibular teeth are malposed or missing, selective grinding procedures can be employed • When occlusal surfaces have large food tables , they can be altered by removing some enamel from buccal and lingual surfaces

48. Single Complete MaxillaryDenture to Opposing Natural Mandibular Teeth with fixed prosthesis • Once a fixed restoration is placed in a dental arch, the restored arch can be thought of as natural teeth opposing a complete denture. • The construction and placement of fixed restorations can correct many occlusal disharmonies that existed previously • The occlusion between the denture teeth and the fixed restorations is harmonized on an articulator Single complete dentures; Ellinger. JPD; Nov, 1951

50. Complete maxillary denture to oppose a partially edentulous arch and a removable partial denture • The most frequently encountered situation for a single complete denture • Replacement of missing posterior teeth in lower arch will improve the prognosis of upper denture • But in class II jaw relation, lower anterior teeth and premolars is enough Single complete dentures; Ellinger. JPD; Nov, 1951