- Email: [email protected]
The immediate overdenture
ORIGINAL ARTICLES
Roots of teeth can be retained in the mouth fo r improved stability and retention of dentures. This method utilizes prefabricated attachments in the roots of natural teeth fo r the construction of an immediate overdenture.
The immediate overdenture S ta n le y F e ld s te in , DDS M itc h e ll T e ite l, DD S, K e w G a rd e n H ills , NY
Natural structures remaining in the mouth may be advantageously used for denture stability and retention. Most often, dentists may think only of the residual alveolar ridges in this regard, but the roots of some otherwise apparently hopeless teeth should be saved for use with denture-retaining devices for stabilization of a lower denture.1 Retention of roots aids the patient in the diffi cult transition from a partial denture to a com plete denture, since many patients do not con sider themselves edentulous until the last root is lost. If the roots are lost later, the patient will adapt easier to a complete denture made without retentive devices, since he has been wearing this type of prosthesis for several years. Retention of roots also preserves discrimina tory tooth proprioception, which leads to a more normalized effect in the final denture.2 The retention of roots for use as denture-re
taining devices also protects the height of the residual alveolar ridge.3 After all teeth are re moved, the residual ridge often seems to resorb rather quickly.4 The retention of several roots seems to retard this resorption. Implants do not slow the resorption in the remaining alveolar bone; and if they happen to fail and are removed, large defects in the bone remain. Patients who originally sought implants probably were unhap py with their previous complete dentures. With additional large bone defects it is almost impos sible to get a satisfactory denture result. Retained teeth are useless as partial denture abutments or fixed-splint abutments because of their extreme mobility and an unfavorable crownroot ratio. The teeth often have only 4 to 5 mm of root structure in bone and 18 mm of structure out of bone. However, these situations are im proved after endodontic and periodontic treat JADA, Vol. 93, October 1976 ■ 775
Fig 1 ■ First two radiographs show unfavorable crown-root ratio. Other two show more favorable crownroot ratio after tooth preparation.
ment, and removal of the entire crown to the gingival surface8,6 (Fig 1). The ratio is even more improved since the retentive device will be positioned so that gripping action of the male portion is 4 mm below the surface of the gingiva, well into the root structure and close to the re maining alveolar bone. This natural root structure, with natural per iodontal ligaments, is far superior to implants or endodontic stabilizers for denture retention. The success rate of these abutments should there fore be much greater than that of implants at their present stage of development. It is important to provide patients with an im mediate replacement for teeth they will lose. The prefabricated attachment* described here easily adapts for use in an immediate denture, thus avoiding a patient’s often unhappy edentulous period during tissue healing and denture con struction. The patient usually has a partial den ture at this time, and an immediate temporary denture can be constructed using it. After heal ing, a new denture is constructed. Another method is to take an impression, and measure vertical dimension and centric relation for construction of the immediate denture; when this is processed, all extractions and tooth prep arations can take place. The same principles apply to either technique, but the latter technique will be discussed here because it is more com prehensive.
D ia g no sis
The final decision between partial dentures and complete dentures is based on many factors be 776 ■ JADA, Vol. 93, October 1976
sides the condition of the remaining teeth. Psy chological considerations, including the patient’s expectations, also are important. The dentist and patient should openly discuss clinical results, length of service, and all other matters. Once the decision for a complete denture is made, which teeth to retain also must be deter mined. The number usually is limited to two or three because of the periodontal condition. But even one tooth retained can be beneficial. The teeth with the best remaining bone support, which are usually those with the least mobility and most favorable crown-root ratio, should be saved. The teeth must be endodontically treat able. It also is favorable to have some remain ing attached gingiva. For ease in home care, widely separated and not adjacent teeth are more desirable. The roots of bicuspids or cuspids are most fa vored for retention since this region on the den ture withstands most of the forces of mastica tion. A good molar or incisor also can be used. But the cuspid or bicuspid region is most favor able for root retention, since the ridge height will be maintained due to the amount of bone resorp tion reduced by retaining these roots.7 The selection of roots to be retained also should be guided by the number of tissue under cuts surrounding the retained roots. Severe bony undercuts or tissue undercuts can be relieved in the final denture; but, if there is a choice, these teeth should be extracted. Severely angulated roots should be avoided because it would be difficult to position the fe male inserts and still keep a relatively easy path of insertion for the final denture. Roots do not have to be parallel. The female portion is con
structed to allow ample room in root selection where parallelism is concerned. Alignment of the female portion within 10° of parallel is ade quate, and female alignment in the roots need not follow the root canal.8
T e c h n iq u e
The teeth to be retained are treated endodontically. This can be done, in vital cases, when the immediate denture is inserted; but it is easier done in advance. Any accepted technique is sat isfactory, but silver wire fillings should not be used. All periodontal therapy, including scaling and curettage, and even surgical elimination of the pockets, if necessary, is then completed. Next, an impression is taken for an immediate denture, with all teeth usually left in position; extractions are performed on denture insertion. A heavy-bodied silicone material, followed by a light-bodied material, makes a satisfactory im pression, but any method can be used. Vertical dimension and centric relation are recorded in the usual manner. After the final try-in, the teeth to be extracted are removed from the master model. The teeth whose roots will be used as re tainers are trimmed on the model leaving about a 4 mm deep cylindrical stump over the root. The tissue surrounding the roots to be retained is not trimmed; it would be unyielding. The tissue sur rounding the extraction sites on the model, how ever, can be routinely trimmed for an immediate denture. The final set-up is made using acrylic resin teeth in the denture areas over the cylin drical stumps. These stumps will leave recesses in the final denture. The male attachment will fit there with a minimum amount of reversegrinding in the denture acrylic resin. After pro cessing, an appointment is made for the extrac tions and insertion of the denture. During the appointment for insertion of the dentures, the crowns of all endodontically treat ed teeth to be retained should be removed to the level of the gingival surface, and the cut-root surfaces are rubber-wheeled and polished (Fig 2). A no. 2 round bur can then be used to start the holes for the female inserts. It should be aligned in the path of insertion to a depth of 4 to 6 mm. The hole is enlarged with a no. 560 carbide bur to a depth of 4 mm. The final hole for the reception of the prefabricated female is then completed with the special diamond sizing bur provided by the manufacturer. (The low-speed bur seems
Fig 2 ■ Nylon male and metal female parts of anchor.
Fig 3 ■ Abutment teeth prepared.
most suitable.) The diamond sizing bur is kept rotating at moderate speed. Water spray from the three-way syringe should be directed under the top flange of the bur to prevent clogging. This diamond instrument is used until a round, flat flange is created on the occlusal surface of the root. The flat flange will act as a receptacle for the occlusal flange on the female insert. When the preparation for the female insert is complete, the female should fit into it like a slightly loosefitting inlay (Fig 3). The preparation and root surface are then dried and treated for two min utes with a 30% stannous fluoride solution, to help prevent decay of the root.9 Males are in serted into the females, so that they are handled more easily and kept free of cement. The females are cemented into the preparations in the roots (Fig 4). An anesthetic is given, and the remain ing teeth that are not being used for anchors are extracted (Fig 5). Undercuts on the labial flanges of the denture around the retained roots must be removed before trying the denture in. The tissue surface of the denture is coated with a relief cream and tried in the mouth. The area of con tact on the tissue side of the denture is relieved until the denture seats firmly and evenly against it, and the male nylon anchors do not prevent the denture from seating. The occlusion is checked using a 30-gauge occlusal indicator wax. The Feldstein—Teitel: IMMEDIATE OVERDENTURE ■ 777
Fig 4 ■ Anchors cemented to place.
after old male inserts are removed and new ones are inserted in the female, to be picked up by the resin. If desired, a new denture can be construct ed after the initial healing period. Patients should be thoroughly trained in the home care of the roots. Thorough daily brushing with a soft nylon brush seems to be adequate to prevent decay and stimulate gingival circulation. Home fluoride treatments can be prescribed. The patient places a few drops of fluoride rinse on the male anchor area in the denture, seats it in place, and wears it for several hours. We have found that decay of the roots occurs only rarely; it is not a major problem even without adequate home care.
S u m m a ry
Fig 5 ■ Mouth prepared to receive denture.
prematurities are adjusted until a good occlusion is obtained. The cold-curing acrylic resin should be mixed and placed in the recesses of the denture, which accommodates the males until they are about three-fourths full. Then the denture should be seated in place while the patient holds it in prop er occlusion until the acrylic resin is set. The denture is removed with the male portion at tached to it, and the female receptacle remains in the root of the prepared tooth. Excess acrylic resin is cut from the base of the male attachment, and the blue centering sleeve is removed from the male attachment. This is a 1 mm shim or spacer, which when removed, allows the denture to be tissue-borne under occlusal forces, and not tooth-borne. Now the root is used only for retention in an occlusal direction, not for the transmission of occlusal forces. After a proper adjustment and healing period, the entire tissue surface of the denture may be relined. This is done with a reline acrylic resin
778 ■ JADA, Vol. 93, October 1976
The use of remaining roots of teeth enhances denture stability and retention. Teeth previously considered hopeless can now be used success fully as an aid in denture retention. The differ ential diagnosis for tooth selection and treatment is discussed, along with a step-by-step tech nique for constructing an immediate denture using prefabricated male and female attach ments. *Zest Anchor, APM—Sterngoid, San Mateo, Calif 94402. Dr. Feldstein and Dr. Teitel are in private practice at 144-01 Jewel Ave, Kew Garden Hills, NY 11367. Address requests for reprints to Dr. Feldstein. 1. Schweitzer, J.M.; Schweitzer, R.D.; and Schweitzer, J. The telescoped complete denture: a research report at the clinical level. J Prosthet Dent 26:357 Oct 1971. 2. Crum, R.J.; Loiselle, R.J.; and Hayes, C.K. The stud attach ment overlay denture and proprioception. JADA 82:583 March 1971. 3. Dodge, C.A. Prevention of complete denture problems by use of overdentures. J Prosthet Dent 30:403 Oct 1973. 4. Tallgren, A. The continuing reduction of the residual alveo lar ridges in complete denture wearers: a mixed-longitudinal study covering 25 years. J Prosthet Dent 27:120 Feb 1972. 5. Loiselle, R.J., and others. The physiologic basis for the over lay denture. J Prosthet Dent 28:4 July 1972. 6. Miller, P.A. Complete dentures supported by natural teeth. J Prosthet Dent 8:924 Nov-Dee 1958. 7. Lord, J.L. and Teel, S. The overdenture. Dent Clin N Am 13: 871 Oct 1969. 8. Zamikoff, 1.1. Overdentures-theory and technique. JADA 86:853 April 1973. 9. Osburn, R.C. Current therapy in dentistry, St. Louis, C. V. Mosby Co., 1974, vol 5, p 325.
Roots of teeth can be retained in the mouth fo r improved stability and retention of dentures. This method utilizes prefabricated attachments in the roots of natural teeth fo r the construction of an immediate overdenture.
The immediate overdenture S ta n le y F e ld s te in , DDS M itc h e ll T e ite l, DD S, K e w G a rd e n H ills , NY
Natural structures remaining in the mouth may be advantageously used for denture stability and retention. Most often, dentists may think only of the residual alveolar ridges in this regard, but the roots of some otherwise apparently hopeless teeth should be saved for use with denture-retaining devices for stabilization of a lower denture.1 Retention of roots aids the patient in the diffi cult transition from a partial denture to a com plete denture, since many patients do not con sider themselves edentulous until the last root is lost. If the roots are lost later, the patient will adapt easier to a complete denture made without retentive devices, since he has been wearing this type of prosthesis for several years. Retention of roots also preserves discrimina tory tooth proprioception, which leads to a more normalized effect in the final denture.2 The retention of roots for use as denture-re
taining devices also protects the height of the residual alveolar ridge.3 After all teeth are re moved, the residual ridge often seems to resorb rather quickly.4 The retention of several roots seems to retard this resorption. Implants do not slow the resorption in the remaining alveolar bone; and if they happen to fail and are removed, large defects in the bone remain. Patients who originally sought implants probably were unhap py with their previous complete dentures. With additional large bone defects it is almost impos sible to get a satisfactory denture result. Retained teeth are useless as partial denture abutments or fixed-splint abutments because of their extreme mobility and an unfavorable crownroot ratio. The teeth often have only 4 to 5 mm of root structure in bone and 18 mm of structure out of bone. However, these situations are im proved after endodontic and periodontic treat JADA, Vol. 93, October 1976 ■ 775
Fig 1 ■ First two radiographs show unfavorable crown-root ratio. Other two show more favorable crownroot ratio after tooth preparation.
ment, and removal of the entire crown to the gingival surface8,6 (Fig 1). The ratio is even more improved since the retentive device will be positioned so that gripping action of the male portion is 4 mm below the surface of the gingiva, well into the root structure and close to the re maining alveolar bone. This natural root structure, with natural per iodontal ligaments, is far superior to implants or endodontic stabilizers for denture retention. The success rate of these abutments should there fore be much greater than that of implants at their present stage of development. It is important to provide patients with an im mediate replacement for teeth they will lose. The prefabricated attachment* described here easily adapts for use in an immediate denture, thus avoiding a patient’s often unhappy edentulous period during tissue healing and denture con struction. The patient usually has a partial den ture at this time, and an immediate temporary denture can be constructed using it. After heal ing, a new denture is constructed. Another method is to take an impression, and measure vertical dimension and centric relation for construction of the immediate denture; when this is processed, all extractions and tooth prep arations can take place. The same principles apply to either technique, but the latter technique will be discussed here because it is more com prehensive.
D ia g no sis
The final decision between partial dentures and complete dentures is based on many factors be 776 ■ JADA, Vol. 93, October 1976
sides the condition of the remaining teeth. Psy chological considerations, including the patient’s expectations, also are important. The dentist and patient should openly discuss clinical results, length of service, and all other matters. Once the decision for a complete denture is made, which teeth to retain also must be deter mined. The number usually is limited to two or three because of the periodontal condition. But even one tooth retained can be beneficial. The teeth with the best remaining bone support, which are usually those with the least mobility and most favorable crown-root ratio, should be saved. The teeth must be endodontically treat able. It also is favorable to have some remain ing attached gingiva. For ease in home care, widely separated and not adjacent teeth are more desirable. The roots of bicuspids or cuspids are most fa vored for retention since this region on the den ture withstands most of the forces of mastica tion. A good molar or incisor also can be used. But the cuspid or bicuspid region is most favor able for root retention, since the ridge height will be maintained due to the amount of bone resorp tion reduced by retaining these roots.7 The selection of roots to be retained also should be guided by the number of tissue under cuts surrounding the retained roots. Severe bony undercuts or tissue undercuts can be relieved in the final denture; but, if there is a choice, these teeth should be extracted. Severely angulated roots should be avoided because it would be difficult to position the fe male inserts and still keep a relatively easy path of insertion for the final denture. Roots do not have to be parallel. The female portion is con
structed to allow ample room in root selection where parallelism is concerned. Alignment of the female portion within 10° of parallel is ade quate, and female alignment in the roots need not follow the root canal.8
T e c h n iq u e
The teeth to be retained are treated endodontically. This can be done, in vital cases, when the immediate denture is inserted; but it is easier done in advance. Any accepted technique is sat isfactory, but silver wire fillings should not be used. All periodontal therapy, including scaling and curettage, and even surgical elimination of the pockets, if necessary, is then completed. Next, an impression is taken for an immediate denture, with all teeth usually left in position; extractions are performed on denture insertion. A heavy-bodied silicone material, followed by a light-bodied material, makes a satisfactory im pression, but any method can be used. Vertical dimension and centric relation are recorded in the usual manner. After the final try-in, the teeth to be extracted are removed from the master model. The teeth whose roots will be used as re tainers are trimmed on the model leaving about a 4 mm deep cylindrical stump over the root. The tissue surrounding the roots to be retained is not trimmed; it would be unyielding. The tissue sur rounding the extraction sites on the model, how ever, can be routinely trimmed for an immediate denture. The final set-up is made using acrylic resin teeth in the denture areas over the cylin drical stumps. These stumps will leave recesses in the final denture. The male attachment will fit there with a minimum amount of reversegrinding in the denture acrylic resin. After pro cessing, an appointment is made for the extrac tions and insertion of the denture. During the appointment for insertion of the dentures, the crowns of all endodontically treat ed teeth to be retained should be removed to the level of the gingival surface, and the cut-root surfaces are rubber-wheeled and polished (Fig 2). A no. 2 round bur can then be used to start the holes for the female inserts. It should be aligned in the path of insertion to a depth of 4 to 6 mm. The hole is enlarged with a no. 560 carbide bur to a depth of 4 mm. The final hole for the reception of the prefabricated female is then completed with the special diamond sizing bur provided by the manufacturer. (The low-speed bur seems
Fig 2 ■ Nylon male and metal female parts of anchor.
Fig 3 ■ Abutment teeth prepared.
most suitable.) The diamond sizing bur is kept rotating at moderate speed. Water spray from the three-way syringe should be directed under the top flange of the bur to prevent clogging. This diamond instrument is used until a round, flat flange is created on the occlusal surface of the root. The flat flange will act as a receptacle for the occlusal flange on the female insert. When the preparation for the female insert is complete, the female should fit into it like a slightly loosefitting inlay (Fig 3). The preparation and root surface are then dried and treated for two min utes with a 30% stannous fluoride solution, to help prevent decay of the root.9 Males are in serted into the females, so that they are handled more easily and kept free of cement. The females are cemented into the preparations in the roots (Fig 4). An anesthetic is given, and the remain ing teeth that are not being used for anchors are extracted (Fig 5). Undercuts on the labial flanges of the denture around the retained roots must be removed before trying the denture in. The tissue surface of the denture is coated with a relief cream and tried in the mouth. The area of con tact on the tissue side of the denture is relieved until the denture seats firmly and evenly against it, and the male nylon anchors do not prevent the denture from seating. The occlusion is checked using a 30-gauge occlusal indicator wax. The Feldstein—Teitel: IMMEDIATE OVERDENTURE ■ 777
Fig 4 ■ Anchors cemented to place.
after old male inserts are removed and new ones are inserted in the female, to be picked up by the resin. If desired, a new denture can be construct ed after the initial healing period. Patients should be thoroughly trained in the home care of the roots. Thorough daily brushing with a soft nylon brush seems to be adequate to prevent decay and stimulate gingival circulation. Home fluoride treatments can be prescribed. The patient places a few drops of fluoride rinse on the male anchor area in the denture, seats it in place, and wears it for several hours. We have found that decay of the roots occurs only rarely; it is not a major problem even without adequate home care.
S u m m a ry
Fig 5 ■ Mouth prepared to receive denture.
prematurities are adjusted until a good occlusion is obtained. The cold-curing acrylic resin should be mixed and placed in the recesses of the denture, which accommodates the males until they are about three-fourths full. Then the denture should be seated in place while the patient holds it in prop er occlusion until the acrylic resin is set. The denture is removed with the male portion at tached to it, and the female receptacle remains in the root of the prepared tooth. Excess acrylic resin is cut from the base of the male attachment, and the blue centering sleeve is removed from the male attachment. This is a 1 mm shim or spacer, which when removed, allows the denture to be tissue-borne under occlusal forces, and not tooth-borne. Now the root is used only for retention in an occlusal direction, not for the transmission of occlusal forces. After a proper adjustment and healing period, the entire tissue surface of the denture may be relined. This is done with a reline acrylic resin
778 ■ JADA, Vol. 93, October 1976
The use of remaining roots of teeth enhances denture stability and retention. Teeth previously considered hopeless can now be used success fully as an aid in denture retention. The differ ential diagnosis for tooth selection and treatment is discussed, along with a step-by-step tech nique for constructing an immediate denture using prefabricated male and female attach ments. *Zest Anchor, APM—Sterngoid, San Mateo, Calif 94402. Dr. Feldstein and Dr. Teitel are in private practice at 144-01 Jewel Ave, Kew Garden Hills, NY 11367. Address requests for reprints to Dr. Feldstein. 1. Schweitzer, J.M.; Schweitzer, R.D.; and Schweitzer, J. The telescoped complete denture: a research report at the clinical level. J Prosthet Dent 26:357 Oct 1971. 2. Crum, R.J.; Loiselle, R.J.; and Hayes, C.K. The stud attach ment overlay denture and proprioception. JADA 82:583 March 1971. 3. Dodge, C.A. Prevention of complete denture problems by use of overdentures. J Prosthet Dent 30:403 Oct 1973. 4. Tallgren, A. The continuing reduction of the residual alveo lar ridges in complete denture wearers: a mixed-longitudinal study covering 25 years. J Prosthet Dent 27:120 Feb 1972. 5. Loiselle, R.J., and others. The physiologic basis for the over lay denture. J Prosthet Dent 28:4 July 1972. 6. Miller, P.A. Complete dentures supported by natural teeth. J Prosthet Dent 8:924 Nov-Dee 1958. 7. Lord, J.L. and Teel, S. The overdenture. Dent Clin N Am 13: 871 Oct 1969. 8. Zamikoff, 1.1. Overdentures-theory and technique. JADA 86:853 April 1973. 9. Osburn, R.C. Current therapy in dentistry, St. Louis, C. V. Mosby Co., 1974, vol 5, p 325.