Relining & rebasing/ Labial orthodontics


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Relining & rebasing/ Labial orthodontics

  1. 1. Relining & Rebasing INDIAN DENTAL ACADEMY Leader in continuing dental education m
  2. 2. Contents  Introduction  Definitions  Indications and contra indications  Diagnosis  Preliminary treatment  Techniques  Bibliography m
  3. 3. INTRODUCTION Materials used in complete denture prosthodontics are vulnerable to certain changes,because the denture may discolor or deteriorate and the artificial teeth can fracture or become abraded. Meticulous attention and care in the construction of complete dentures will minimize adverse changes in the supporting tissues and associated facial structures as well. The clinical efforts that aim at prolonging the useful life of complete dentures involve in refitting of the impression surface of the denture by means of a reline or a rebase procedure. m
  4. 4. m
  5. 5. Definition  Reline:- the procedures used to resurface the tissue side of a denture with new base material,thus producing an accurate adaptation to the denture foundation area.  Rebase:- the laboratory process of replacing the entire denture base material on an existing prosthesis. m
  6. 6. Treatment Rationale: The denture foundation changes adversely as a result of varying degrees and rates of residual ridge resorbtion. These changes are insidious and rapid, but they are progressive and inevitable, and are usually accompanied by one or more features: 1. Loss of retention and stability. 2. Loss of vertical dimension of occlusion. 3. Loss of support of facial tissues. 4. Horizontal shift of dentures: incorrect occlusal relationship. 5. Reorientation of occlusal m
  7. 7. The magnitude of observed clinical changes allows a decision to be made as to whether the prescribed resurfacing will necessitate a reline or a rebase. Observed clinical changes: 1. Loss of retention and stability. 2. Loss of vertical dimension of occlusion. 3. Loss of support of facial tissues. 4. Horizontal shift of dentures: incorrect occlusal relationship. 5. Reorientation of occlusal plane. Reline RebaseMinimal to moderate Moderate to maximal Treatment Rationale: m
  8. 8. Treatment Rationale: The resultant spatial reorientation of the dentures on their supporting tissues and occlusal surfaces leads to changes in circum oral support and, consequently, in the patient's appearance. The changes in occlusal relationships also induce more adverse stresses on the supporting tissues,which weightens the risk of further ridge resorbtion. m
  9. 9. Diagnosis: A through diagnosis of the changes must be made before any clinical procedures are started. It is necessary to determine the nature of the changes as well as their extent and location. Patients who have worn dentures successfully for a long time often return for their service because of looseness, soreness, chewing inefficiency, or esthetic changes. These difficulties may have been caused by 1. An incorrect or unbalanced occlusion that existed at the time of dentures were inserted. 2. Changes in the structures supporting the dentures that may or may not have been associated with a disharmonious occlusion. So it is essential that the cause of the difficulties must be corrected before the treatment is started m
  10. 10. Diagnosis: Dentures with built in errors in occlusion may not need relining. They may need only to have the occlusion corrected. If the occlusion has induced a gradual loss of retention, tissue rest followed by a new CR record with remounting and regrinding will eliminate the cause and make the dentures comfortable and serviceable without relining.a change in the basal seat of the dentures usually is revealed by looseness, soreness, inflammation, loss of Occlusal Vertical Dimension, esthetics. m
  11. 11. Diagnosis: An examination of the oral mucosa that supports the dentures will disclose the state of its health. When the tissue is badly irritated, occlusal disharmony associated with loss vertical dimension should be suspected. Unsatisfactory changes in esthetics indicates a loss of vertical dimension, even though the teeth may seen to occlude properly. If the supporting tissues are traumatized, surgical correction to eliminate the hyperplasia may be necessary before relining impressions are m
  12. 12. Diagnosis: Shrinkage of the bone of the maxilla usually permits the upper denture to move up and back in relation to its original position. However the occlusion also may force the maxillary denture forward. The lower denture usually moves downward and forward, but it may move down and back relative to the mandible as shrinkage occurs. Concurrently, the mandible moves to a higher position when the teeth are in occlusion than it occupied with the teeth in occlusion before the shrinkage occurred. This movement is rotary around a line approximately through the condyles. This mandibular rotation can elicit severe damage in the denture supporting tissues over a long period of unsupervised denture wear. It also must be determined whether shrinkage of the jaws has been uniform under both dentures or whether one ridge has been destroyed more than the other. Greater shrinkage in one arch will change the orientation of the occlusal plane. This will cause occlusal disharmony in eccentric occlusion, even though the Occlusal Vertical Dimension has been re established by relining. m
  13. 13. Indications: Relining & Rebasing  Immediate dentures at three to six months after their construction.  When the residual alveolar ridge have resorbed and the adaptation of the denture bases to the ridges is poor.  When the patient cannot afford the cost of having the new dentures constructed.  when the construction of new dentures with the accompanying series of appointments can cause physical or mental stresses, such as for geriatric or chronically ill patients. m
  14. 14. General considerations: A thorough examination of the patient and the existing dentures must be accomplished before commencing therapy : 1. OVD should be satisfactory. 2. Co should coincide with CR. 3. The patients appearance must be acceptable to the patient and the dentist. The size, shape, shade and arrangement of the artificial teeth must be satisfactory. 4. The oral tissue must be in optimum health. 5. The posterior limit of the maxillary denture is correct. m
  15. 15. General considerations: contd ……… 6. The denture base extensions are adequate. 7. The denture base extensions ensure distribution of masticatory forces over a large area as possible. 8. The inter occlusal distance is correct. 9. Speech is satisfactory with the existing teeth arrangement. 10. There are no hard or soft tissue conditions that would preclude the technique, such as redundant tissue or severe bony undercuts. m
  16. 16. Contraindications: 1. When an excessive amount of resorbtion has taken place. 2. When abused soft tissue are present. 3. When the patient has TMJ problems. 4. Denture with poor esthetics or unsatisfactory jaw relations. 5. Dentures with major speech problem. 6. Severe osseous undercuts. m
  17. 17. RELINING / REBASING TECHNIQUES:- Clinical Procedures: m
  18. 18. Tissue Preparation: Excessive hypertrophic tissue should be surgically removed. The oral mucosa must be free of irritations. Removal of the dentures from the mouth during sleep is a must for several weeks before treatment commences. The dentures should be left out of the mouth at least two to three days before making the final impression. Daily massage of the soft tissues is helpful to stimulate their blood supply. m
  19. 19. Denture preparation: 1. Pressure areas on the soft tissue surface of the dentures should be relieved. 2. Minor occlusal disharmony is corrected by selective grinding. 3. Small border inadequacies are corrected. 4. A correct posterior palatal seal area should be established before the final impression. m
  20. 20. Principal pitfalls: 1. Do not increase the OVD. 2. Multiple even contacts(maximum intercuspation) must be present in centric relation. 3. Do not allow the maxillary denture to move forward during impression making. 4. Ensure that centric occlusion and centric relation are identical. 5. Ensure that accurate posterior palatal seal has been established. 6. Equal thickness of final impression material should be used. m
  21. 21. Impression procedures: The clinical relining or rebasing can be achieved by- 1. Static impression technique. Closed mouth Open mouth 2. Functional impression technique. m
  22. 22. Static Impression Technique : Closed mouth technique: The dentures are used as impression trays, normally the existing centric occlusion is employed to the denture with the lining impression material or else the CR is recorded (in the registration medium of choice) before the impressions are made. Open mouth technique: Relining/rebasing of both maxillary and mandibular dentures can be done at the same appointment. The dentures are used as trays for making new impressions. The existing CO is not utilised, and a new CR record is obtained after the impressions are made. m
  23. 23. Functional Impression technique: This method is simple and practical. Often one may see a variable hyperemia of mucosa accompanied by sore spots in the denture bearing mucosa. The denture is observed intraorally to asses the need for peripheral reduction or extension, and a posterior palatal seal extension is developed with modeling compound on maxillary dentures. If extensive ridge resorbtion and overt loss of V D of occlusion have occurred, three compound stops may be required on the impression surface of the denture to reestablish proper occlusal relationship or to improve the occlusal plane orientation. m
  24. 24. Functional Impression technique: A treatment liner is next placed inside the denture. The lining material should flow evenly to cover the denture with a thin layer. If voids are evident, they should be filled with new mix of liner material. Unsupported liner material may occur on the borders, and this indicates border molding with green stick compound. Or else the material has a slumping tendency when unsupported. m
  25. 25. Functional Impression technique: Plastic Stage : Elastic Stage : Firm Stage : Tissue conditioner materials are used. This material sets in three stages. Denture base responds to functional/parafunctional stresses; fit is improved. Stress is cushioned and tissue recovery takes place. Surface similar to polymerized resin, except it is vulnerable to m
  26. 26. Functional Impression technique: Precautions:  Pour the cast when the material reaches the firm stage.  Peripheral or surface deterioration can occur.  Voids con occur during placement of material in the denture. m
  27. 27. Denture Lining Materials Denture lining materials are of several types and are used for variety of reasons. Either the whole of the denture base can be replaced with fresh heat curing acrylic resin, or a lining of a self curing may be applied to the fitting surface of the existing base. Some times it is necessary to apply a very soft material to the fitting surface of a denture in order to act as a ‘cushion’ which will enable traumatized soft tissue to recover before recording an impression for a new denture. m
  28. 28. Classification: The materials can be classified into 3 groups:  Hard reline materials.  Tissue conditioners.  Soft lining materials. m
  29. 29. Hard reline material: The materials are used to provide a chair side reline to the denture. Composition: The materials are generally supplied as a powder and liquid which are mixed together. There are two types according to the composition, they are Type I and Type II . The major difference between them is that the liquid in type I contains MMA monomer, while in type II the liquid contains BMA monomer. Both the materials are classified as autopolymerizing m
  30. 30. Composition of typical hard reline materials. m
  31. 31. Hard reline material: Manipulation: Relieve the fitting surface of the denture. Mix powder and liquid in 1:2.5 to attain a fluid mix. Applied to the fitting surface of the denture and seated in patients mouth whilst still fluid. The reline soon becomes rubbery and the impression of the patients soft tissue is recorded. The denture is allowed to bench cure after removal from the patients mouth. Warm water will accelerate the curing. The relined denture is ready within 30 minutes. m
  32. 32. Hard reline material: Properties: Type II is less irritant than Type I. Both the types have lower glass transition temperature (Tg). Therefore the plasticizer in Type I and higher methyl acrylates in Type II are added. So this will lead to increased dimensional stability in the relined denture(particularly, if the denture has been relieved in order to accommodate the lining. m
  33. 33. Hard reline material: Disadvantages: Direct contact of the material in the oral cavity leads to irritation and sensitization. Reline materials are often porous due to air inclusions. Easily colonized by microorganisms including Candida albicans. Difficult to clean. Increase in thickness of the denture and reducing the free way space. This material should be considered as semi permanent solution to the problem of an ill fitting m
  34. 34. Tissue Conditioners: Tissue conditioners are soft denture liners. They are used to provide a temporary cushion which prevents the masticatory loads from being transferred to the underlying soft and hard tissues. Traumatized soft tissue due to wearing an ill fitting denture. Applied on dentures of patients who have undergone surgery, extraction. To fill the gap to assist with stabilization of the prosthesis at the same time of the insertion of the immediate denture. Used as a functional impression material. m
  35. 35. Tissue Conditioners: Requirements:  Should remain soft during use in order to maintain cushioning effect.  Material should be resilient, that the masticatory loads can be absorbed without causing permanent deformation of the lining.  When these materials are being used to obtain a functional impression a degree of permanent deformation ender load is required. This enables the impression of the soft tissue to be altered during normal m
  36. 36. Tissue Conditioners: Composition: Supplied as powder and liquid components and are mixed together. Powder – polymethylmethacrylate – polymer beads. Liquid - Ehtyl alcohol - solvent. - Butylpthalyl butylglycolate - plasticizer. The relative amounts of plasticizer and solvent vary from one product to another. These variations control the softness and elasticity of the set material. Pigment may also be present to give a pink color. m
  37. 37. Tissue Conditioners: Composition: contd... The liquid component contains no monomer and the powder has no initiator. When the powder and the liquid are mixed together, a purely physical process occurs. The solvent dissolves the smaller polymer beads and the larger beads become swollen with solvent and acts as a carrier for the plasticizer. The final set material is gel like, with swollen plasticized spheres being cemented together with a matrix which is a saturated solution of polymer in a solvent / plasticizer mixture. The softness of the material is due to the use of higher methacrylate, ethyl methacrylate, coupled with considerable quantities of plasticizer and m
  38. 38. Tissue Conditioners: Manipulation: Powder and liquid mixed and applied to the fitting surface of the denture. This material undergoes through Plastic stage - few hrs – few days. Elastic stage - 1 – 2 weeks. Firm stage - after 15 days. m
  39. 39. Tissue Conditioners: Properties: These materials are soft and viscoelastic, therefore these materials are able to perform the functions of both a tissue conditioner and functional impression material. They do not permanently remain soft since the alcohol and plasticizer are leeched rapidly into saliva. The elastic nature of the material is time dependent. They are non irritant due to the absence of acrylic monomers from the liquid m
  40. 40. Soft Lining Materials: Soft or plasticized acrylic, vinyl polymers copolymers, as well as natural and silicone rubber products have been used as soft denture liners. Suggested for patients with abused denture bearing mucosa, areas of severe undercuts, or congenital or acquired defects of the palate. Some materials have an inhibitory effect on Candida albicans. They are of *Temporary / mouth cured soft liners. *Permanent / processed soft m
  41. 41. Soft Lining Materials: Desired Properties:  High bond strength to the denture base.  Dimensional stability of the liner during & after processing.  Permanent softness or resilience.  Low water sorption therefore reduced leeching of plasticizer and solvent into saliva.  Color stability.  Ease of processing.  m
  42. 42. Temporary Soft Lining Materials : These materials are similar to the tissue conditioners. These are used for short periods (up to several weeks) to improve the comfort and fit of an old denture until it can be remade or permanently relined. They are not as soft as tissue conditioners, but they retain their softness for a longer time. They are also viscoelastic, give cushioning effect. Oxygenating type of cleansers cause surface degradation and pitting of the m
  43. 43. Temporary Soft Lining Materials : Used as a means of temporarily improving the fit of an ill- fitting denture until a new denture is constructed. As a diagnostic aid to ascertain whether the patient would benefit from a permanent soft lining. Both the tissue conditioners and temporary liners go hard. When this occurs the surface is both rough and irregular, increasing the risk of trauma. Manipulation is similar to that as tissue conditioners. Simple rinsing with water is better than using peroxide based denture soaking the denture over night in diluted sodium hypochlorite help to minimize infection risk. m
  44. 44. Permanent Soft lining Material: Permanent soft lining materials are used for patients who cannot tolerate a hard base. If the patient has an irregular mandibular alveolar ridge covered by a thin and a non resilient mucosa, it may be very painful when a masticatory load is applied through a hard base on to this type of supporting tissue. In such cases, a permanent soft lining is done to increase patient comfort and acceptance of the denture. m
  45. 45. Permanent Soft lining Material: Requirements:  Permanently soft.  Cushioning effect.  Prevent unacceptable distortions during service.  Lining should adhere to the denture base.  Non-toxic, non-irritant.  It must prevent growth of harmful bacteria and fungi. m
  46. 46. Permanent Soft lining Material: D en tu re soft R elin ers C old cure H eat cu re A crylic C on d en sation A d d ition C old cu re H eat cu re S ilicon e P olyp h osp h azin e m
  47. 47. Those products described as cold curing acrylic materials temporary soft lining materials. Heat curing acrylic materials are processed in the lab and are normally applied to a new denture at the time of production. They are supplied as powder and liquid. Softness rely on the combined use of higher methacrylate and a plasticizer. A typical powder consists beads of polyethyl or polybutylmethacrylate along with some peroxide initiator and pigments. The liquid consists of butylmethacrylate and plasticizer . Powder & Liquid mixed to for a dough which is heat processed simultaneously with the hard acrylic base. Permanent Soft lining Material: m
  48. 48. Permanent Soft lining Material: A similar technique is used when applying a heat curing silicone soft lining. These products are supplied in a single paste which contains poly- dimethylsiloxane polymer with pendent or terminal vinyl groups through which cross linking takes place. The liquid polymer is formulated into a paste by adding inert fillers such as silica. The paste also contains free radical initiator such as peroxide which breaks down on heating to initiate cross linking reaction. These vinyl groups undergo chain extension cross linking. This results in elasticity of the material. m
  49. 49. Permanent Soft lining Material: The two types of cold curing silicones elastomers are used as soft lining materials. They are analogous to addition and condensation curing impression materials. Condensation types are supplied as a paste & liquid. The paste contains poly-dimethylsiloxane liquid polymer and inert filler. The liquid contains a mixture of cross linking agent, such as tetraethyl silicate and a catalyst, an organo-tin compound such as dibutyl-tin-diluarate. On mixing the paste and liquid a condensation cross linking reaction takes place. m
  50. 50. Permanent Soft lining Material: Alcohol is produced as a by product of this reaction. Cross-linking causes the paste to be converted in to a rubber. The addition curing silicones are supplied as two pastes which are proportioned and mixed using a cartridge or a gun system. There is cross linking between the two prepolymers. Cold cured are cured at room temperature. m
  51. 51. Permanent Soft lining Material: Polyphosphazine fluoroelastomers are recently available. They are supplied in sheet forms and are manipulated in a similar to the heat cured silicone products. Recommended curing is either at 74`C for 8hrs or 74`C for 2 ½hrs, followed by 100`C for 30min. m
  52. 52. Permanent Soft lining Material: Properties: All types of soft lining materials are sufficiently soft on insertion to give an adequate cushioning effect. The softest of the four materials initially are the cold curing acrylic materials.these products become harder faster due to loss of alcohol and slow leeching of plasticizer. The silicone materials remain permanently soft, modulus of elasticity may decrease due to water absorption. The durability of bond between denture ant the lining material is adequate for the acrylic materials and the heat cured silicone products. 2-3 mm of thickness is required for ideal cushioning effect. m
  53. 53. CLOSED MOUTH RELINE TECHNIQUE Maxillary Denture m
  54. 54. Shaffer FW & Filler WH Relining tech: Centric Relation: CR is recorded before the impression is made, using modeling compound or wax. Denture Preparation: the denture is prepared before making the impression by relieving 1.5 – 2 mm from the tissue surface. The borders are reduced 1 – 2 mm except the posterior border of the maxillary denture. Special suggestion: A large portion of the mid palatal portion of the maxillary denture is removed for visibility in positioning the denture during impression m
  55. 55. Shaffer FW & Filler WH Relining tech: Border molding:the borders of the dentures are reformed to their functional contours by low fusing modeling compound. Impression: Zinc oxide euginol is used as the impression material. During the border molding and impression making, the patient closes lightly into the premade interocclusal record. m
  56. 56. Shaffer FW & Filler WH Relining tech: Advantages: The opening of the palatal portion will allow better seating of the maxillary denture and alleviate the increase in vertical dimension pitfall. The premade interocclusal records helps to position the dentures during impression making and to orient the dentures on the articulator. The two step technique will reduce the possibility of moving of the maxillary denture forward during the final impression making. m
  57. 57. Shaffer FW & Filler WH Relining tech: Disadvantages: The possibility of moving the maxillary denture is still a major problem. The wax interocclusal record is not an accurate and safe record that the patient can close on several times with out the possibility of damaging the record. This technique does not suggest any solution for difficulties of relining both dentures at the same time. m
  58. 58. Hansen NJ relining method: Centric relation: Existing CO and intercuspation are used as a means to seat the dentures. Denture Preparation: The denture is prepared before making the impression by relieving 1.5 – 2 mm from the tissue surface. The borders are reduced 1 – 2 mm except the posterior border of the maxillary denture. Special suggestion: A large part of palatal section is prepared to be removed as follows: 1. The outline area should be indicated and deepened on the polished surface up to half the thickness of the base. 2. Holes are drilled at 5 – 6 mm intervals inside the groove. This procedure is suggested for easy removal of the palatal portion during packing and processing. m
  59. 59. Hansen NJ relining method: Border molding:the borders of the dentures are reformed to their functional contours by low fusing modeling compound (green stick compound). Impression: A wax that flows at mouth temperature, such as Kerr’s impression wax(lowa wax) is the material of choice in this technique. The impression is made in two steps. The impression of the labial flange and the crest of the alveolar ridge between the canines is made as a second step. m
  60. 60. Hansen NJ relining method: Advantage: The two step impression technique will reduce the possibility of extreme forward movementof the maxillary denture. Disadvantage: 1. Wax impression material is difficult to work with and possibility of distortion exists. 2. Errors of existing centric occlusion can produce an in accurate impression. m
  61. 61. Christensen method for relining: Centric relation: Existing CO and intercuspation are used as a means to seat the dentures. Denture Preparation: The denture is prepared before making the impression by relieving 1.5 – 2 mm from the tissue surface. The borders are reduced 1 – 2 mm except the posterior border of the maxillary denture. m
  62. 62. Christensen method for relining: Special suggestion:The labial and palatal flanges of the denture are perforated, these perforations will decrease the pressure during impression making procedure, thereby preventing displacement of maxillary denture. Border molding:the borders of the dentures are reformed to their functional contours by low fusing modeling compound (green stick compound). m
  63. 63. Christensen method for relining: Impression : No specific impression material is suggested. Advantages: Reduced movement of the maxillary denture during impression making. Disadvantages: The possibility of moving the maxillary denture is still a major problem. This technique does not suggest any solution for difficulties of relining both dentures at the same time. m
  64. 64. Relining by Jordan LG: Centric relation: Existing CO and intercuspation are used as a means to seat the dentures. Denture Preparation: The denture is prepared before making the impression by relieving 1.5 – 2 mm from the tissue surface. The borders are reduced 1 – 2 mm except the posterior border of the maxillary denture. m
  65. 65. Relining by Jordan LG: Special suggestions: 1. The denture periphery should be shortened to create a flat border. 2. A large opening shoud be prepared in the palatal portion of the denture. 3. Adhesive tape is attached over the buccal and labial surfaces of both dentures 2mm away from the denture borders. 4. With a knife edge stone, a fairly deep groove should be cut into the buccal and labial surfaces of the dentures at the junction of the impression material and filled with molten base plate wax. m
  66. 66. Relining by Jordan LG: Border molding: Border molding has not been suggested, but during impression making it has been emphasized that a slight amount of impression material should be left on the flattened borders. Impression: Zinc oxide euginol is suggested for the first step of impression making, and impression plaster for the second step (palatal portion). m
  67. 67. Relining by Jordan LG: Advantages: The opening of the palatal portion will allow better seating of the maxillary denture and alleviate the increase in vertical dimension pitfall. The two step technique will reduce the possibility of moving of the maxillary denture forward during the final impression making. Disadvantages: Though it has been suggested that the patient should not seat the denture by closing on it, the existing errors of CO may produce some pressure points and a faulty impression can m
  68. 68. CLOSED MOUTH RELINE TECHNIQUE Mandibular Denture m
  69. 69. Gillis RR Relining technique: Centric Relation: The existing CO(intercuspation) is used as a means to seat the mandibular denture during secondary impression. The occlusion is corrected during the establishment of a new occlusal vertical dimension. Denture preparation: if required, not mandatory. m
  70. 70. Gillis RR Relining technique: Special suggestions:Loss of VD is corrected by luting softened modeling compound to the occlusal surface of the mandibular posterior teeth. The patient is directed to repeatedly pronounce the word “m”. The record is chilled, trimmed and slightly heated before returning it into the patients mouth. The procedure is repeated until the OVD is established to operators satisfaction. Then a lower work impression should be made. After pouring an inpression and mounting the lower denture on an articulator, the lower denture should be removed and m
  71. 71. Gillis RR Relining technique: Any excessive undercuts should be removed. The denture is luted to the maxillary denture in maximum intercuspation. Softened modeling compound is placed inside the mandibular denture and the articulator closed against the lower cast to contact the incisal guide pin. With this procedure, the amount of VD indicated by the thickness of the compound on the surfaces of the mandibular teeth is transferred to the base of the mandibular denture. The mandibular denture at this stage is used as a tray for making the final m
  72. 72. Gillis RR Relining technique: Impression: Green stick compound for border molding, and zinc oxide euginol for making the secondary impression are suggested. Advantages: 1. The loss of VD can be compensated during the relining procedures. 2. The error in CO can be reduced during the laboratory stages. Disadvantages: 1. Time consuming, both laboratorial and clinical standpoint.. 2. The procedure for establishing OVD is highly m
  73. 73. OPEN MOUTH IMPRESSION TECHNIQUE: Relining for maxillary and mandibular dentures at the same time. After the maxillary and mandibular impressions are made, a new centric record is established. All in single appointment. m
  74. 74. CO Boucher’s technique: Centric relation: Utilizing both dentures as recording bases, the jaw relation record is established after making the secondary impressions of both the dentures. Denture preparation: A posterior palatal seal is formed in modeling compound on the maxillary denture before any other changes are made on the tissue side of the denture. 1mm space is provided inside the denture for the impression material. The borders are shortened 1mm to allow space for impression material to form a new border. m
  75. 75. CO Boucher’s technique: Special suggestion: The lower denture is prepared for the reline impression in exactly the same way as a trey would be prepared for making a new denture. The buccal surfaces of the lingual flanges are ground to minimize the pressure against the mylohyoid ridges and between the tissues of the floor of the mouth and the buccal sides of the lingual flanges. The lingual flange between the premylohyoid eminences is shortened by 1mm. m
  76. 76. CO Boucher’s technique: The labial flange between the buccal notches is shortened by 1mm. Two grooves are cut on the buccal sides of the lingual flange to facilitate the removal of the retromylohyoid eminence after the cast is poured. A modeling compound handle formed over the lower anterior teeth, facilitates handling the denture when it is carried to the mouth. Adhesive or masking tape is adapted over the polished surface of both dentures, and the teeth. m
  77. 77. CO Boucher’s technique: Border molding: If flanges are inadequate, the borders should be corrected with modeling compound. Impression: Zinc oxide euginol is suggested i.e., exactly 15 sec after the denture has been placed in the mouth, the patient is asked to pull his lip down and to open hos mouth wide. These actions mold the impression material over the border of the denture. The upper denture is laid aside until the lower impression has been made. m
  78. 78. CO Boucher’s technique: Advantages: 1. Special trimming of the denture and making room for the impression material will facilitate the making of a reasonable impression during the selective pressure impression technique without any occlusal interference. 2. A separate interocclusal record using already made impressions as the recording bases will allow the operator to concentrate on recording the jaw relation. 3. It is possible to verify CR record. 4. The inter occlusal record, is reliable. m
  79. 79. CO Boucher’s technique: Disadvantages: 1. Although this technique seems simple, the performance of the procedures is not easy. 2. This technique requires more clinical and laboratory time. m
  80. 80. Winkler’s technique :  Patient must be educated concerning the procedures and especially about not wearing dentures overnight.  Old denture should be closely examined and errors of occlusion corrected, until satisfactory centric occlusion is achieved which should coincident with centric relation.  The basal surface of the denture is reduced to allow room for the tissue conditioning material.  The surface is dried before the placement of the material. m
  81. 81. Winkler’s technique :  A minimum thickness of the tissue conditioning material is placed over the tissue surface of the denture and evenly distributed.  The denture is then inserted in the mouth with proper antero-posterior relationship.  The patient is instructed to tap the teeth together lightly, to position the denture, and to hold the teethe together lightly for three minutes.  Then the patient is engaged in conversation or to read out loudly for additional 5 m
  82. 82. Winkler’s technique :  The denture is removed from the patients mouth and excess is removed from the polished surface.  The basal surface is inspected. If any pressure spots seen, must be relieved and more material is added by brush on technique.  Voids must be avoided during the loading of material. If seen remove and add fresh mix.  Over extended borders must be m
  83. 83. Winkler’s technique :  Then reinserted in the patients mouth, and the patient is sent. And called after 15 days ie. After the material has attained the firm stage.  The material is reviewed periodically, never allow the material to become a source of irritation.  When the tissue has returned to normal healthy state, the patient is scheduled for impression making.  At this time a zinc-oxide euginol impression or a light bodied polysulfide rubber wash impression also can be made. m
  84. 84. Winkler’s technique : Laboratory Procedure:  The impression is boxed and the cast is poured in artificial stone.  Mount the cast on a semi adjustable articulator using a face-bow transfer record.a jig can also be used. Even though it is easier than the articulator, it is less accurate, especially when additional occlusal adjustments are required.  Relate the mandibular denture to the maxillary denture, which is already on the articulator using an interocclusal m
  85. 85. Winkler’s technique :  If any occlusal discrepancy exists, it should be corrected before separating the impressions from the casts, by using selective grinding procedure.  The procedures of relining and rebasing are same until this stage. During the laboratory phase of a rebasing procedure, all of the old denture base is replaced by new material without changing the arrangement of teeth.  when the dentures are finished, plaster plaster remount casts are made and the maxillary cast mounted on the m
  86. 86. Winkler’s technique : Insertion procedure:  A pressure indicating paste is used to locate pressure areas. They are carefully relieved by grinding with mounting stones.  A new interocclusal record is used to mount the lower denture in centric relation.  Mounting must be verified before adjusting the occlusion.  the occlusion must be perfected at the correct OVD using selective grinding procedure.  Before dismissing the patient the occlusion is again checked. m
  87. 87. Conclusion  Resurfacing and replacement of the denture base of a complete denture is a complicated procedure requiring astute clinical judgment and skill if the therapy is to be successful. Often, the fabrication of new dentures utilizing a sound technique should be the treatment of choice, especially when the denture bases are under-extended; when there has been a gross loss in the occlusal vertical dimension, and when centric relation and centric occlusion do not coincide Utilization of fluid resins (tissue conditioning material) presently seems to be the material of choice to ensure success with restoration of masticatory efficiency m
  88. 88. Bibliography  Nikzad S. Javid, , john F. Bowman ; Relining and Rebasing Techniques  Essentials of compete denture prosthodontics; 341-354   Boucher CO; the relining of complete dentures  J Prosthet Dent.1973;30;521-526  Bowman J; relining full upper and lower dentures  DCNA 1977; 21; 361-378  Christensen FT; relining techniques for complete dentures.  J Prosthet Dent. 1971; 26; 373-381  Hansen NJ; Relining and rebasing complete dentures a technique.  DCNA 1964; 8; 693-704 m
  89. 89.  Jordan LG relining the complete maxillary denture.  J Prosthet Dent. 1972; 28; 637-641  Koein IE, Broner AS; complete denture secondary impression technique to minimize distortion of ridge and border tissues.  J Prosthet Dent.1985; 54; 660-664  Smith KE, Lord JL, Bolender CL; complete denture relining with auto polymerizing acrylic resin processed in water under air pressure.  J Prosthet Dent. 1967; 18; 103-115  Tucker KM; relining compete denture with the use of a functional impression.  J Prosthet Dent. 1966; 16; m
  90. 90. m