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Tissue response to overdenture therapy
Tissue response to overdenture therapy Aaron H. Fenton, D.D.S., M.S., F.R.C.D.(C),’ and Neil Hahn, D.D.S. ‘The IJniversity of Toronto, Faculty of Dentistry. Toronto, Canada
P
rosthodontic patients must cope with the problem of gradual and continuous loss of alveolar bone following the extraction of teeth. The magnitude of this change is highly variable and has been documented in longitudinal studies by Tallgren,’ Carlsson:’ and Atwood and Coy.’ The complete or removable partial dentures necessary to treat the tooth loss will require periodic relines or replacement as tissues continue to change. Overton and Bramblett’ estimated the effects of this problem in terms of dentist-hours required for provision of service in the United States. Their projections point to an increasing need every year for the next decade. In Ontario, there has been a 27% increase in the segment of the population over 60 years of age between 1961 and 197l.j Statistics indicate that this trend will continue through the year 2000 as the postwar boom babies age and move through society. The inference from these studies is that there will be an increasing need for prosthodontic care in the future. In an attempt to minimize the loss of alveolar bone and subsequent need for prosthodontic care, some dentists have recommended the retention of a few strategically located tooth roots to support overdentures. Many other advantages of overdentures have been listed and discussed.“-” The purpose of this study was to assess the status of abutment teeth and their supporting tissues following overdenture therapy.
LITERATURE REVIEW There have only been a few reports indicating the results of overdenture therapy, and most articles imply that home care is a significant factor affecting the long-term results.” Read before the C>reatw New York Academy SW York, N. \r *.bwciatc Professor
492
NOVEMBER
of Prosthodontics,
of I’rosthodontics.
1978
VOLUME
40
NUMBER
5
Dolder” recalled 110 patients who had received dentures that were retained by metal bars soldered between gold copings on nonvital tooth roots. Over a 2-year observation period he reported a 10% incidence of caries and a mean PMA Index of 1.63. Rantanen and associates” examined 33 patients who had dentures retained by precision attachments on nonvital tooth roots. The patients had received treatment from 6 months to 4 years previously. Thirty-nine percent of the teeth were carious. and thirty-five percent had deepened pockets. Other authors have been more optimistic about the conditions of tissues under overdentures. Morrow and associates” evaluated 20 nonvital tooth roots that were covered with gold copings and metal-base overdentures. Three to eight months after placement of the overdentures, the teeth were t-e-examined, and no significant differences were found in the pocket depths or mobility.
METHOD The patients in this study were treated in the undergraduate clinic of the Faculty of Dentistry at the University of Toronto. Overdenture therapy had heen provided for patients when the following criteria could be satisfied: (1) the patients wished to retain some teeth; (2) the teeth had a poor prognosis as abutments for conventionaf fixed or removable prostheses (Fig. 1); (3) the patients appeared to have a poor prognosis for successful adaptation to complete dentures; and (4) a few remaining tooth roots could be rendered caries free and periodontally sound (Fig. 2). The prosthetic, periodontal, endodontic, and restorative care were provided to uniform standards. Most teeth were treated endodonticalfy and the pulp chamber sealed with silver amalgam. The remaining tooth surface was prepared to a short convex contour (Fig. 3). Cast-gold restorations were used only when necessary to produce this contour (Fig. 4).
0022~3913/78/110492
+ 07$00.70/00
1978 The
C
V
Mcsby
Co.
Fig. 1. A single tooth with a poor prognosis as a conventional abutment. Fig. 2. Preparation of the tooth root for an overdenture.
Fig. 3. Prepared tooth roots 3 months following insertion of the overdenture Fig. 4. Cast-gold copings at the Z-year recall.
Examination protocol Two examiners were selected so that observations could be made on a simultaneous but independent basis.‘j. l6 Then a variety of indices were evaluated, and the indices reported in this article were selected as most valid. A patient identification code and computer card system were developed to record data for analysis. The examiners practiced the recording procedures in consultation with experienced staff members to calibrate their judgments and produce maximum reliability. During the actual study, 10 of the 17 patients were reexamined on separate occasions to assessobserver variability. All patients were examined by both examiners independently at the same appointment. On a random basis, one examiner first acted as observer and dictated his findings to the second examiner, who recorded the results. Then the examiners exchanged places and a second set of observations were made. The results were compared and any differekes in assessment were resolved. Overlaid
THE fOURNAL
OF F‘ROSTHETK
DENTISTRY
teeth were only scored if the patients had been wearing their overdentures. control tooth scores were obtained from 10 of the overdenture patients who also had retnaining natural anterior tee& that were not involved with any type of prosthesis or restoration near the gingival margin (Fig. 5). After the examination, any necessary treatment such as scaling or denture adjustment was provided. Oral hygiene habits were reviewed, and the patient was given 1 ounce of fluoride gel with instructions to place a drop inside his denture each day until the gel was all used up (Fig. 6).
Treatment of data The following data were collected and, where applicable, scored as numbers on computer cards: Patient response. The patients’ subjective response to treatment, assessment of the prostheses, and oral hygiene habits were noted. Prosthetic status. The conditions of the prostheses were assessed with respect to stability, retention, occlusion, and articulation.*’
493
TISSUE RESPONSE
TO OVERDENTURES
3mm overdenture tooth crowns
control clinical crowns
Fig. 7. Comparison of tooth mobility. Six of the seventeen patients were using or had used fluoride drops inside their dentures; the remain-
der had not. Prosthetic status. The retention of the prostheses was adequate. The examiners formed a distinct clinical impression that the overdentures were more stabie than conventional complete dentures and that the overdentures were more resistant to movement from occlusal or lateral loading than complete dentures would be if they were constructed on the same anatomy without tooth support. Changes in were negligible, with the occlusion and articulation one exception. One patient had received a mandibular overdenture with two tooth roots retained unilat-
erally. The occlusion on the edentulous side was deficient, and it appeared that alveolar resorption had occurred
there
tooth-supported
when
it was compared
to the
side. This overdenture was relined
and the occlusion
corrected.
status of overlaid teeth compared to control teeth Of the 59 teeth
originally
treated,
2 had
surface,
and
it was our
opinion
that
this
probably contributed to plaque accumulation and decay of the tooth. After the tooth was restored, a localized
reline was provided.
Eight of the thirty-seven teeth that did not receive fluoride had developed root surface caries. One
THE JOURNAL
OF PROSTHETIC
DENTISTRY
index
Table Ii. Results of tooth retention Score 0
1
2
3
St&US
No caries, no calculus, no imperfect margin of dental restoration in a gingival location Supragingival cavity, calculus, or imperfect margin of dental restoration Subgingival cavity, calculus, or imperfect margin of dental restoration Large cavity, abundance of calculus, or grossly insufficient marginal fit of dental restoration in a supragingival and/or subgingival location
scores of 3 for
index Overlaid teeth
Control teeth
21
12
19
25
12
17
5
3
been
extracted before our examination, 1 had developed a periodontal abscess, and 1 had a root fracture during endodontic therapy. Two teeth had developed periodontal abscesses, but they had been treated and retained. Caries had developed on one of the 20 teeth that had received fluoride gel applications. The inner surface of the denture was not well adapted to the tooth
Fig. 8. An overlaid tooth with retention, plaque, and gingivitis.
patient with poor oral hygiene accounted for four of the eight carious teeth and perhaps irsi?ated this value. None of the control teeth had developed any carious lesions. Mobility index. The shortened tooth roots under overdentures were considerably less mobile than the control tooth crowns of the same patients (Table I). Consequently, the mean mobility of overlaid teeth was less than that of the control crowns. Hawever, there was much individual variation, particularly in the control tooth sample (Fig. 7). Retention index. Insignificant
differences were found between the retention indices of overlaid and control teeth (Table II), but as might be anticipated,
495
FENTON
Table III. Results of plaque
N=12
Fig. 9. Comparison of the retention and mandibular overlaid teeth.
Overlaid teeth
Status
0
No plaque in the gingival area A film of plaque adhering to the free gingival margin and adjacent area of the toothThe plaque may only be recognized by running a probe across the tooth surface Moderate accumulation of soft deposits within the gingival pocket, on the gingival margin and/or adjacent teeth surface, which can be seen by the naked eye Abundance of soft matter within the gingival pocket and/or on the gingival margin and adjacent tooth surface
2
index of maxillary
3
Table IV. Results of the gingival status
0 1
Normal gingiva Mild inflammation-slight change in color, slight edema; no bleeding on probing Moderate inflammation-redness, edema and glazing; bleeding on probing Severe inflammation-marked redness and edema; ulceration; tendency to spontaneous bleeding
INDEX
INDEX
INDEX
DEPTHmm.
Fig. 10. Tissue response of overdenture teeth compared to control teeth. mandibular anterior teeth were prone to the development of calculus formation (Fig. 8). This was the reason for differences in the means when maxillary overlaid teeth were compared to mandibular overlaid teeth (Fig. 9). Plaque index. Insignificant differences and almost parallel scores were recorded for the presence of plaque on teeth (Table III). Gingival index. The gingival index (GI) scores of the control teeth were quite uniform, while the scores of the overlaid teeth had more spread. In the overlaid tooth sample, more teeth were healthier (GI 0 = 9) and more teeth had marked gingivitis (GI 3 = 8) than in the control tooth sample (Table IV). Pocket depths. There were insignificant differences between the mean pocket depths of overlaid teeth and control teeth. These four indices are displayed in Fig. 10.
3
Control teeth
7
0
36
29
11
20
3
index Overlaid teeth
SCOrp
2
HAHN
index
SCOlV
I
AND
Control teeth
9
0
22
40
18
17
8
0
Change in status of overlaid teeth with tlme The total population of overdenture patients was divided into three groups based on time elapsed since the completion of treatment with overdentures (Fig. 11). The plaque index showed a slight but insignificant rise with time (Fig. 12), while the gingival index decreased after the first 10 months (Fig. 13). We attributed this change to the improved denture base adaptation following the initial postinsertion and reline phase of treatment.
DISCUSSION At The University of Toronto we have recommended a philosophy of treatment whereby overdentures are only recommended to preserve the last few tooth roots for an otherwise complete denture. NOVEMBER
1978
VOLUME
40
NUMBER
5
TISSUE RESPONSE TO OVERDENTURES
N = 17
6*
0 - 10 11-20 21.- 30 POST-TREATMENT TIME IN MONTHS
TIME IN MONTHS Fig.
11.
Elapsed time since overdenture
treatment.
Usually this involves treatment of the two remaining mandibular canine roots to minimize advanced alveolar resorption which one would predict in some patients if the tooth roots were lost. Occasionally maxillary anterior tooth roots are retained if the mandible has a large number of remaining teeth such that the occlusal support in the mandible is considerably greater than in the maxillae, The teeth are used for support of a prosthesis only and not for retention. Precision attachments are not used because of the additional service required and because of their potential for plaque accumulation. In essence, immediate dentures are constructed for patients. Instead of surgerizing the entire cast for denture construction, the anticipated tooth preparations are made on the stone cast where teeth are to be retained. Then at the time of denture insertion these teeth are prepared rather than extracted, and the denture is inserted and supported on the remaining tooth roots. Relining is provided as necessary to maintain the fit of the denture base. If a suitable prognosis can be predicted for a sufficient number of teeth, then our patients are treated with fixed or removable prostheses as indicated. Nyman and associate?” have reported excellent results for therapy involving extensive fixed partial dentures and splinting of periodontally involved teeth with reduced periodontal support. In addition to proper technical procedures, they emphasize the necessity of dentists and patients identifying and removing all dentogingival plaque to avoid periodontal inflammation. Zander and associates” have stated that the goals of periodontal therapy are still removal of plaque and calculus by the dentist and maintenance of this situation by the patient. The major objective of our tissue preparation is to leave structures that can be easily maintained by the patient. Periodontal theraTHE JOURNAL
OF PROSTHETIC
DENTISTRY
OVERDENTURE TEETH o 4C-,@--*A*
Fig.
12.
Change in plaque index with time.
POST-TREATMENT TIME IN MONTHS Fig. 13. Change in gingival index with time. py is provided as necessary for the remaining tooth roots, and they are prepared to a low, smooth, convex contour 1 to 3 mm above the gingiva. The design of the prosthesis is as simple as possible. The inner surface of the denture base is acrylic resin processed to fit accurately on the underlying teeth and soft tissues. Disclosing paste and observation of the tissue response are used as criteria to assess the contact of the acrylic resin in the region of the marginal gingiva. The resin is adjusted and smoothed to avoid gingival irritation. At the same time, spaces must be avoided between the denture base and the gingiva, since additional plaque tends to accumulate and the gingiva sometimes hypertrophies to fill the void. Patients in this study were given repeated demonstrations and encouragement to practice adequate home care measures during their periodontal and prosthodontic treatments, but no recalls were arranged unless the patient took the initiative to make an appointment. 497
FENTON ANtl IjAtlN
We hoped that this regimen would parallel the care that patients would receive in private practice. In fact, patients treated by their own dentist would probably be recalled and supervised more effectively than the patients in our clinic population. On recall for this study, the most common treatment required was scaling of the remaining tooth roots and removal of stains from the dentures. Oral hygiene and diet analysis were reviewed with each patient as necessary. Carlsson and associate? have documented the problems of caries, increasing tooth mobility, and gingivitis that can be associated with abutment teeth. On the other hand, Derry and Bertram’” have been able to demonstrate successful maintenance of dental health with removabls prostheses when home care and recalls are emphasized.
5. 6.
7. 8.
9. 10. II.
12. 13.
SUh4MARY AND CONCLUSIONS Patients who had received overdenture treatment provided with uniform standards were recalled and studied. Two examiners simultaneously and independently evaluated the tissue response using a variety of indices. Data comparisons were made between overlaid teeth and control teeth and between overlaid teeth as a function of time to assess any effects of the treatment. Patients who did not apply fluoride to retained tooth roots had a high incidence of caries. No other significant differences were noted between the health of overlaid teeth compared to control teeth. Patients demonstrated large variations in their ability to maintain low plaque levels and healthy tissues. Despite this, on a longitudinal basis over 2 years, patients were able to maintain plaque levels and gingival response at clinically acceptable standards.
17.
REFERENCES
21.
I.
Tallgren, A.: The continuing reduction of the residual alveolar ridges in complete denture wearers: A mixed longitudinal study covering 25 years. J PROST~~T DEKI. 27:120, 1972. 2. (‘a&son, G. E.: Changes in the jaws and facial profile after extractions and prosthetic treatment. Trans Roy Sch Dent Series 2:12, 1967. 3. Atwood, D. A., and Coy, W. A.: Clinical, cephalometric, and dcnsitometric study of reduction of residual ridges, J PROST~IET DENT 26:280, 197 1. 4. Overton, R. G., and Bramblett, R. M.: Prosthodontic services. A study of heed and availability in the United States. J PROSTIIETDENT 27:329, 1972.
14.
15.
16.
18.
19. 20.
22.
Ministry of Community and Social Services, The l’r~~virlcc oi Ontario: “People’s Data on Senior Citizens.” ,Juric 107,; hqorrow. K. M., Feldmann, E. I;.. Rudd. K I) ;d l‘rovillion. H. M.: Tooth supported complcw dcncurcs: -\[I approach to preventive prosthodontics. ,J I’KOS~III~I 1)t.h I 21:513, 1969. Lord, J, L., and Teel. S.: The overdcnture. Dcn~ (:lin Xorth Am 13:871. 1969. Loiselle, R. J.. Crum, R. J.. Rooney. C;. E., and Stuctw. C. H.: The physiologic basis for the ovrrlav dcnlurc ,J PROSTHET DEW 28~4. 1972. Brewer, A. .4.. and Fenton, A. H.: l‘he overdenturv. I)enc Clin Sorth Am 17:723, 1973. Brewer, .4. .4.. and Morrow, K. M.: Ovrrdenrurrs. St Louis. 1975, The C. V. Mosby Co.. p “69. Yalisovc. J. I..: Crown and sleeve-coping retainer\ for removable partial prostheses. J PROSWET DLVT 16: 1069. 1966. Dolder, E. J.: ‘l’he bar joint mandibular denturr. ,J PRUS~I~FT DEKl 11:689. 1961. Rantanen, T., MMlkill, h;.. Yli-Urpo. A., and Siiriki. l-i.: Investigations of the therapeutic success with dentures retained by precision attachments. Suom HammasllLk Toim 673356, 197 I. Morrow. R. M., Powell, J. M., Jam&on. W. S.. Jcnson. I.. G., and Rudd, K. D.: Tooth-supported complete dentures: Description and clinical evaluation of a simplified trchnique. .J PROWHEI DEKI 22:414, 1969. Mark& K-E.: Studies of deviations between observers 1n clinico-odontological recording. Umei Rrs I.ibrary 2:8, 1962. Chilton. N. \\‘.I Design and Analysis in Dental and Oral Research. Philadelphia and Toronto, 1967, .J. B. I.ippincott Co.. p 363. Bergman, B., Carlsson, G. E., and Hedegard, B.: .4 longitudinal two-vear study of a number of full denture: cases. Arta Odontol &and 22:3. 1964. Dewy, .4., and Bertram, U.: A clinical survey of wmovable partial dentures after 2 yrar\ usage. .Acta Odontol Sand 28:581, 1971. Liie. H.: The gingival index. the plaque indrx, and the retention index systems. .J Periodontal 38:610, 1967. Nyman. S., Lindhe, J.. and Lundgrcn. I>.: ‘l’hc rote of occlusion for the stability of fixed bridges in patients with reduced periodontal tissue support. ,J Clin Periodontol 2:j:$, 1975. Zander. H. A.. Poison, A. M.. and Hei,jl, I.. Cl.: Goals of periodontal therapy. ,J Periodontal 47:261, 1976. Carlsson, C. E., Hedegard, B., and Koivumaa, K. K.: The current place of removable partial dentures in restorative dentistry. Dent Clin North .4m 14:553. 1970.
Hcprinl re9uxls lo: DR. hROK H. Ftwo.u FACW n OF DENTISTRY 124 EDWARD 5. ‘rORONT0
ONTARIO M5G IG6. CAMDA
NOVEMBER
1976
VOLUME
40
NUMBER
5
P
rosthodontic patients must cope with the problem of gradual and continuous loss of alveolar bone following the extraction of teeth. The magnitude of this change is highly variable and has been documented in longitudinal studies by Tallgren,’ Carlsson:’ and Atwood and Coy.’ The complete or removable partial dentures necessary to treat the tooth loss will require periodic relines or replacement as tissues continue to change. Overton and Bramblett’ estimated the effects of this problem in terms of dentist-hours required for provision of service in the United States. Their projections point to an increasing need every year for the next decade. In Ontario, there has been a 27% increase in the segment of the population over 60 years of age between 1961 and 197l.j Statistics indicate that this trend will continue through the year 2000 as the postwar boom babies age and move through society. The inference from these studies is that there will be an increasing need for prosthodontic care in the future. In an attempt to minimize the loss of alveolar bone and subsequent need for prosthodontic care, some dentists have recommended the retention of a few strategically located tooth roots to support overdentures. Many other advantages of overdentures have been listed and discussed.“-” The purpose of this study was to assess the status of abutment teeth and their supporting tissues following overdenture therapy.
LITERATURE REVIEW There have only been a few reports indicating the results of overdenture therapy, and most articles imply that home care is a significant factor affecting the long-term results.” Read before the C>reatw New York Academy SW York, N. \r *.bwciatc Professor
492
NOVEMBER
of Prosthodontics,
of I’rosthodontics.
1978
VOLUME
40
NUMBER
5
Dolder” recalled 110 patients who had received dentures that were retained by metal bars soldered between gold copings on nonvital tooth roots. Over a 2-year observation period he reported a 10% incidence of caries and a mean PMA Index of 1.63. Rantanen and associates” examined 33 patients who had dentures retained by precision attachments on nonvital tooth roots. The patients had received treatment from 6 months to 4 years previously. Thirty-nine percent of the teeth were carious. and thirty-five percent had deepened pockets. Other authors have been more optimistic about the conditions of tissues under overdentures. Morrow and associates” evaluated 20 nonvital tooth roots that were covered with gold copings and metal-base overdentures. Three to eight months after placement of the overdentures, the teeth were t-e-examined, and no significant differences were found in the pocket depths or mobility.
METHOD The patients in this study were treated in the undergraduate clinic of the Faculty of Dentistry at the University of Toronto. Overdenture therapy had heen provided for patients when the following criteria could be satisfied: (1) the patients wished to retain some teeth; (2) the teeth had a poor prognosis as abutments for conventionaf fixed or removable prostheses (Fig. 1); (3) the patients appeared to have a poor prognosis for successful adaptation to complete dentures; and (4) a few remaining tooth roots could be rendered caries free and periodontally sound (Fig. 2). The prosthetic, periodontal, endodontic, and restorative care were provided to uniform standards. Most teeth were treated endodonticalfy and the pulp chamber sealed with silver amalgam. The remaining tooth surface was prepared to a short convex contour (Fig. 3). Cast-gold restorations were used only when necessary to produce this contour (Fig. 4).
0022~3913/78/110492
+ 07$00.70/00
1978 The
C
V
Mcsby
Co.
Fig. 1. A single tooth with a poor prognosis as a conventional abutment. Fig. 2. Preparation of the tooth root for an overdenture.
Fig. 3. Prepared tooth roots 3 months following insertion of the overdenture Fig. 4. Cast-gold copings at the Z-year recall.
Examination protocol Two examiners were selected so that observations could be made on a simultaneous but independent basis.‘j. l6 Then a variety of indices were evaluated, and the indices reported in this article were selected as most valid. A patient identification code and computer card system were developed to record data for analysis. The examiners practiced the recording procedures in consultation with experienced staff members to calibrate their judgments and produce maximum reliability. During the actual study, 10 of the 17 patients were reexamined on separate occasions to assessobserver variability. All patients were examined by both examiners independently at the same appointment. On a random basis, one examiner first acted as observer and dictated his findings to the second examiner, who recorded the results. Then the examiners exchanged places and a second set of observations were made. The results were compared and any differekes in assessment were resolved. Overlaid
THE fOURNAL
OF F‘ROSTHETK
DENTISTRY
teeth were only scored if the patients had been wearing their overdentures. control tooth scores were obtained from 10 of the overdenture patients who also had retnaining natural anterior tee& that were not involved with any type of prosthesis or restoration near the gingival margin (Fig. 5). After the examination, any necessary treatment such as scaling or denture adjustment was provided. Oral hygiene habits were reviewed, and the patient was given 1 ounce of fluoride gel with instructions to place a drop inside his denture each day until the gel was all used up (Fig. 6).
Treatment of data The following data were collected and, where applicable, scored as numbers on computer cards: Patient response. The patients’ subjective response to treatment, assessment of the prostheses, and oral hygiene habits were noted. Prosthetic status. The conditions of the prostheses were assessed with respect to stability, retention, occlusion, and articulation.*’
493
TISSUE RESPONSE
TO OVERDENTURES
3mm overdenture tooth crowns
control clinical crowns
Fig. 7. Comparison of tooth mobility. Six of the seventeen patients were using or had used fluoride drops inside their dentures; the remain-
der had not. Prosthetic status. The retention of the prostheses was adequate. The examiners formed a distinct clinical impression that the overdentures were more stabie than conventional complete dentures and that the overdentures were more resistant to movement from occlusal or lateral loading than complete dentures would be if they were constructed on the same anatomy without tooth support. Changes in were negligible, with the occlusion and articulation one exception. One patient had received a mandibular overdenture with two tooth roots retained unilat-
erally. The occlusion on the edentulous side was deficient, and it appeared that alveolar resorption had occurred
there
tooth-supported
when
it was compared
to the
side. This overdenture was relined
and the occlusion
corrected.
status of overlaid teeth compared to control teeth Of the 59 teeth
originally
treated,
2 had
surface,
and
it was our
opinion
that
this
probably contributed to plaque accumulation and decay of the tooth. After the tooth was restored, a localized
reline was provided.
Eight of the thirty-seven teeth that did not receive fluoride had developed root surface caries. One
THE JOURNAL
OF PROSTHETIC
DENTISTRY
index
Table Ii. Results of tooth retention Score 0
1
2
3
St&US
No caries, no calculus, no imperfect margin of dental restoration in a gingival location Supragingival cavity, calculus, or imperfect margin of dental restoration Subgingival cavity, calculus, or imperfect margin of dental restoration Large cavity, abundance of calculus, or grossly insufficient marginal fit of dental restoration in a supragingival and/or subgingival location
scores of 3 for
index Overlaid teeth
Control teeth
21
12
19
25
12
17
5
3
been
extracted before our examination, 1 had developed a periodontal abscess, and 1 had a root fracture during endodontic therapy. Two teeth had developed periodontal abscesses, but they had been treated and retained. Caries had developed on one of the 20 teeth that had received fluoride gel applications. The inner surface of the denture was not well adapted to the tooth
Fig. 8. An overlaid tooth with retention, plaque, and gingivitis.
patient with poor oral hygiene accounted for four of the eight carious teeth and perhaps irsi?ated this value. None of the control teeth had developed any carious lesions. Mobility index. The shortened tooth roots under overdentures were considerably less mobile than the control tooth crowns of the same patients (Table I). Consequently, the mean mobility of overlaid teeth was less than that of the control crowns. Hawever, there was much individual variation, particularly in the control tooth sample (Fig. 7). Retention index. Insignificant
differences were found between the retention indices of overlaid and control teeth (Table II), but as might be anticipated,
495
FENTON
Table III. Results of plaque
N=12
Fig. 9. Comparison of the retention and mandibular overlaid teeth.
Overlaid teeth
Status
0
No plaque in the gingival area A film of plaque adhering to the free gingival margin and adjacent area of the toothThe plaque may only be recognized by running a probe across the tooth surface Moderate accumulation of soft deposits within the gingival pocket, on the gingival margin and/or adjacent teeth surface, which can be seen by the naked eye Abundance of soft matter within the gingival pocket and/or on the gingival margin and adjacent tooth surface
2
index of maxillary
3
Table IV. Results of the gingival status
0 1
Normal gingiva Mild inflammation-slight change in color, slight edema; no bleeding on probing Moderate inflammation-redness, edema and glazing; bleeding on probing Severe inflammation-marked redness and edema; ulceration; tendency to spontaneous bleeding
INDEX
INDEX
INDEX
DEPTHmm.
Fig. 10. Tissue response of overdenture teeth compared to control teeth. mandibular anterior teeth were prone to the development of calculus formation (Fig. 8). This was the reason for differences in the means when maxillary overlaid teeth were compared to mandibular overlaid teeth (Fig. 9). Plaque index. Insignificant differences and almost parallel scores were recorded for the presence of plaque on teeth (Table III). Gingival index. The gingival index (GI) scores of the control teeth were quite uniform, while the scores of the overlaid teeth had more spread. In the overlaid tooth sample, more teeth were healthier (GI 0 = 9) and more teeth had marked gingivitis (GI 3 = 8) than in the control tooth sample (Table IV). Pocket depths. There were insignificant differences between the mean pocket depths of overlaid teeth and control teeth. These four indices are displayed in Fig. 10.
3
Control teeth
7
0
36
29
11
20
3
index Overlaid teeth
SCOrp
2
HAHN
index
SCOlV
I
AND
Control teeth
9
0
22
40
18
17
8
0
Change in status of overlaid teeth with tlme The total population of overdenture patients was divided into three groups based on time elapsed since the completion of treatment with overdentures (Fig. 11). The plaque index showed a slight but insignificant rise with time (Fig. 12), while the gingival index decreased after the first 10 months (Fig. 13). We attributed this change to the improved denture base adaptation following the initial postinsertion and reline phase of treatment.
DISCUSSION At The University of Toronto we have recommended a philosophy of treatment whereby overdentures are only recommended to preserve the last few tooth roots for an otherwise complete denture. NOVEMBER
1978
VOLUME
40
NUMBER
5
TISSUE RESPONSE TO OVERDENTURES
N = 17
6*
0 - 10 11-20 21.- 30 POST-TREATMENT TIME IN MONTHS
TIME IN MONTHS Fig.
11.
Elapsed time since overdenture
treatment.
Usually this involves treatment of the two remaining mandibular canine roots to minimize advanced alveolar resorption which one would predict in some patients if the tooth roots were lost. Occasionally maxillary anterior tooth roots are retained if the mandible has a large number of remaining teeth such that the occlusal support in the mandible is considerably greater than in the maxillae, The teeth are used for support of a prosthesis only and not for retention. Precision attachments are not used because of the additional service required and because of their potential for plaque accumulation. In essence, immediate dentures are constructed for patients. Instead of surgerizing the entire cast for denture construction, the anticipated tooth preparations are made on the stone cast where teeth are to be retained. Then at the time of denture insertion these teeth are prepared rather than extracted, and the denture is inserted and supported on the remaining tooth roots. Relining is provided as necessary to maintain the fit of the denture base. If a suitable prognosis can be predicted for a sufficient number of teeth, then our patients are treated with fixed or removable prostheses as indicated. Nyman and associate?” have reported excellent results for therapy involving extensive fixed partial dentures and splinting of periodontally involved teeth with reduced periodontal support. In addition to proper technical procedures, they emphasize the necessity of dentists and patients identifying and removing all dentogingival plaque to avoid periodontal inflammation. Zander and associates” have stated that the goals of periodontal therapy are still removal of plaque and calculus by the dentist and maintenance of this situation by the patient. The major objective of our tissue preparation is to leave structures that can be easily maintained by the patient. Periodontal theraTHE JOURNAL
OF PROSTHETIC
DENTISTRY
OVERDENTURE TEETH o 4C-,@--*A*
Fig.
12.
Change in plaque index with time.
POST-TREATMENT TIME IN MONTHS Fig. 13. Change in gingival index with time. py is provided as necessary for the remaining tooth roots, and they are prepared to a low, smooth, convex contour 1 to 3 mm above the gingiva. The design of the prosthesis is as simple as possible. The inner surface of the denture base is acrylic resin processed to fit accurately on the underlying teeth and soft tissues. Disclosing paste and observation of the tissue response are used as criteria to assess the contact of the acrylic resin in the region of the marginal gingiva. The resin is adjusted and smoothed to avoid gingival irritation. At the same time, spaces must be avoided between the denture base and the gingiva, since additional plaque tends to accumulate and the gingiva sometimes hypertrophies to fill the void. Patients in this study were given repeated demonstrations and encouragement to practice adequate home care measures during their periodontal and prosthodontic treatments, but no recalls were arranged unless the patient took the initiative to make an appointment. 497
FENTON ANtl IjAtlN
We hoped that this regimen would parallel the care that patients would receive in private practice. In fact, patients treated by their own dentist would probably be recalled and supervised more effectively than the patients in our clinic population. On recall for this study, the most common treatment required was scaling of the remaining tooth roots and removal of stains from the dentures. Oral hygiene and diet analysis were reviewed with each patient as necessary. Carlsson and associate? have documented the problems of caries, increasing tooth mobility, and gingivitis that can be associated with abutment teeth. On the other hand, Derry and Bertram’” have been able to demonstrate successful maintenance of dental health with removabls prostheses when home care and recalls are emphasized.
5. 6.
7. 8.
9. 10. II.
12. 13.
SUh4MARY AND CONCLUSIONS Patients who had received overdenture treatment provided with uniform standards were recalled and studied. Two examiners simultaneously and independently evaluated the tissue response using a variety of indices. Data comparisons were made between overlaid teeth and control teeth and between overlaid teeth as a function of time to assess any effects of the treatment. Patients who did not apply fluoride to retained tooth roots had a high incidence of caries. No other significant differences were noted between the health of overlaid teeth compared to control teeth. Patients demonstrated large variations in their ability to maintain low plaque levels and healthy tissues. Despite this, on a longitudinal basis over 2 years, patients were able to maintain plaque levels and gingival response at clinically acceptable standards.
17.
REFERENCES
21.
I.
Tallgren, A.: The continuing reduction of the residual alveolar ridges in complete denture wearers: A mixed longitudinal study covering 25 years. J PROST~~T DEKI. 27:120, 1972. 2. (‘a&son, G. E.: Changes in the jaws and facial profile after extractions and prosthetic treatment. Trans Roy Sch Dent Series 2:12, 1967. 3. Atwood, D. A., and Coy, W. A.: Clinical, cephalometric, and dcnsitometric study of reduction of residual ridges, J PROST~IET DENT 26:280, 197 1. 4. Overton, R. G., and Bramblett, R. M.: Prosthodontic services. A study of heed and availability in the United States. J PROSTIIETDENT 27:329, 1972.
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Ministry of Community and Social Services, The l’r~~virlcc oi Ontario: “People’s Data on Senior Citizens.” ,Juric 107,; hqorrow. K. M., Feldmann, E. I;.. Rudd. K I) ;d l‘rovillion. H. M.: Tooth supported complcw dcncurcs: -\[I approach to preventive prosthodontics. ,J I’KOS~III~I 1)t.h I 21:513, 1969. Lord, J, L., and Teel. S.: The overdcnture. Dcn~ (:lin Xorth Am 13:871. 1969. Loiselle, R. J.. Crum, R. J.. Rooney. C;. E., and Stuctw. C. H.: The physiologic basis for the ovrrlav dcnlurc ,J PROSTHET DEW 28~4. 1972. Brewer, A. .4.. and Fenton, A. H.: l‘he overdenturv. I)enc Clin Sorth Am 17:723, 1973. Brewer, .4. .4.. and Morrow, K. M.: Ovrrdenrurrs. St Louis. 1975, The C. V. Mosby Co.. p “69. Yalisovc. J. I..: Crown and sleeve-coping retainer\ for removable partial prostheses. J PROSWET DLVT 16: 1069. 1966. Dolder, E. J.: ‘l’he bar joint mandibular denturr. ,J PRUS~I~FT DEKl 11:689. 1961. Rantanen, T., MMlkill, h;.. Yli-Urpo. A., and Siiriki. l-i.: Investigations of the therapeutic success with dentures retained by precision attachments. Suom HammasllLk Toim 673356, 197 I. Morrow. R. M., Powell, J. M., Jam&on. W. S.. Jcnson. I.. G., and Rudd, K. D.: Tooth-supported complete dentures: Description and clinical evaluation of a simplified trchnique. .J PROWHEI DEKI 22:414, 1969. Mark& K-E.: Studies of deviations between observers 1n clinico-odontological recording. Umei Rrs I.ibrary 2:8, 1962. Chilton. N. \\‘.I Design and Analysis in Dental and Oral Research. Philadelphia and Toronto, 1967, .J. B. I.ippincott Co.. p 363. Bergman, B., Carlsson, G. E., and Hedegard, B.: .4 longitudinal two-vear study of a number of full denture: cases. Arta Odontol &and 22:3. 1964. Dewy, .4., and Bertram, U.: A clinical survey of wmovable partial dentures after 2 yrar\ usage. .Acta Odontol Sand 28:581, 1971. Liie. H.: The gingival index. the plaque indrx, and the retention index systems. .J Periodontal 38:610, 1967. Nyman. S., Lindhe, J.. and Lundgrcn. I>.: ‘l’hc rote of occlusion for the stability of fixed bridges in patients with reduced periodontal tissue support. ,J Clin Periodontol 2:j:$, 1975. Zander. H. A.. Poison, A. M.. and Hei,jl, I.. Cl.: Goals of periodontal therapy. ,J Periodontal 47:261, 1976. Carlsson, C. E., Hedegard, B., and Koivumaa, K. K.: The current place of removable partial dentures in restorative dentistry. Dent Clin North .4m 14:553. 1970.
Hcprinl re9uxls lo: DR. hROK H. Ftwo.u FACW n OF DENTISTRY 124 EDWARD 5. ‘rORONT0
ONTARIO M5G IG6. CAMDA
NOVEMBER
1976
VOLUME
40
NUMBER
5