Download - A clinical evaluation of removable partial dentures with I-bar retainers. Part I

REMOVABLE PROSTHODONTICS

A clinical evaluation of removable partial dentures with I-bar retainers. Part I

David Benson, D.D.S., M.S.,* and Vladimir W. Spolsky, D.M.D., M.P.H.** University of California, School of Dentistry, Los Angeles, C:alif.

T here are many methods for making removable partial dentures, and the advocates of each concept claim success. Clinical experience alone is not sufficient documentation to determine the relative merits of any particular removable partial denture philoso- phy. Laboratory research is necessary to analyze and understand the forces created by removable partial dentures, while clinical studies are essential to evaluate the overall effects of the prosthesis on the oral tissues. Kratochvil and Caputo’ and Thompson and associates’ have analyzed, with photoelastic models, the forces generated by removable partial dentures using a mesial rest, long distal guiding planes, and I-bar retainers. According to Kratochvil and Capu- to,’ the physiologic adjustment of extension-type removable partial denture frameworks in the mouth alleviates adverse tipping forces on abutment teeth and directs the forces within the long axes of the teeth. Thompson and associates’ analyzed seven commonly used removable partial denture designs and found the mesial rest and I-bar retainer exhib- ited the most favorable distribution of vertically applied forces.

The purpose of this study was to make a clinical evaluation of patients wearing removable partial dentures to determine the status of the periodon- tium, teeth, occlusion, and the prosthesis itself. One hundred thirty-five tooth-supported and extension removable partial dentures made at the UCLA School of Dentistry using the concepts of a mesial rest for extension prostheses, long guiding planes, and I-bar retainers” were clinically evaluated (Fig. 1). This study will be reported in two parts due to the

Read before Pacific Coast Society of Prosthodontists, Newport

Beach, Calif. *Associate Clinical Professor and Chairman, Section of Remov-

able Prosthodontics. **Associate Professor, Section of Preventive Dentistry and Public

Health.

246 MARCH 1979 VOLUME 41 NUMBER 3

Fig. 1. The design of the I-bar retainer on the removable partial dentures evaluated.

extensive amount of data collected during the 7 years of the study.

METHODS AND MATERIALS

Patient sample. All patients selected in this study were treated in the UCLA School of Dentistry by junior and senior dental students. The patients were contacted, in order by year they had been treated, to return for a clinical evaluation of their prostheses. Because of the transient nature of this dental school’s population, less than 10% of the patients contacted returned for an evaluation. This study was conducted on an annual basis over a ‘I-year period, and therefore it was possible to reevaluate some patients two or more times, depending on the patient’s interest and availability.

Removable partial denture construction. ‘l’he removable partial dentures that were clinically evaluated were made using the principles and methods advocated by Kratochvil.” Although emphasis was placed on the design involving the abutment teeth of extension removable partial dentures using a me&l rest, long distal guiding planes, and E-bar retainers (Fig. l), other equally important considerations

0022-3913/79/030246 + 09$00.90/0 v 151758 ‘l‘hc (1. V. Mosbv (3,

DENTIJRES WITH J-BAR RETAINERS

‘Table I. t1onditions and criteria used for evaluation of patients with partiai dentures -__.-- --___ -.. ---_.---

Condition evaluated Evaluation criteria’

1 Prrsent general health P”Ol fair gwd 2 Prosthesis acceptam P PO”, fair i:Oi’l! 3. Oral hygiene pool fair &,OCJC 4. General gingival health P”CX tar $,O<lG 5. Abutment gingival health poor fair pd 6 Tissue under denture base poor I‘ur ~;““c: 7. Existing restorations poor fair $,OOd

8. Framework fit poor fair @Od

9. Iietention POW fair ),LWd 10. Maintenance of prosthesis p001 fair p?oc! I 1. Occlusal wear of artificial teeth none slight moderate excessive 12. Slide from terminal hinge to habitual occlusal position none slight moderate ts>cessivr 13. Extension base displacement none slight moderate t,xcessiw 14. Centric prematurities yes II” IS. ‘Tooth mobility 1 2 3 :

16. Periodontal pockets Millimeters 17. Tooth decay Tooth surface 18. Framework and denture base fractures Number and location

-- *Evaluation criteria: poor = 1; fair = 2; good = 3. none = 0; slight = 1; moderate = 2; rxcessiuc = 3. F~S = I; no =. ?

were incorporated into the removable partial denture construction. Mounted pretreatment diag- nostic casts were surveyed and designed to incorpo- rate the principle of using positive rests to control tooth position and direct forces apically. Long guiding planes were used to brace the remaining teeth and reunite the arch, and attention was given in the design of the partial denture components to promote maximum natural stimulation at the tooth-tissue junction of the teeth. I-bar retainers placed into a O.Ol-inch undercut were used for primary retention. For all extension dentures, the removable partial denture framework* was physiologically adjusted in the mouth, using chloroform and rouge, to relieve the forces that can be created on abutment teeth by the rotation of the removable partial denture during function.’ An altered cast impression was made on all patients requiring extension dentures to afford optimum tissue support and stability for the denture base. At the placement of each removable partial denture, pressure-indicating paste and a periphery wax were used to adjust the denture base to the tissues, and a patient remount procedure was done to refine the occlusion. The occlusion for all patients was restored in the terminal hinge position and subsequently equilibrated to provide maximum centric stops both in the retruded and habitual closing positions. Either canine-guided occlusion or <group function was used for lateral excursions,

*VitaIlium. f1ownedica Co.. Inc.. C:hicago, 111.

depending on the existing occlusion and what was considered normal occlusion for each patient. Plastic artificial teeth were used only when there was inadequate space for porcelain teeth or against opposing natural teeth. Otherwise porcelain teeth were used. Amalgam restorations were placed in all centric stops on the plastic teeth to minimize occlusal wear.

CLINICAL EVALUATION

The criteria used to evaluate each patient and removable partial denture are listed in Table I. Each patient was interviewed and given a thorough oral clinical examination, the removable partial denture design was transferred to a dia.gnostic cast made for each partially edentulous jaw, and intraoral photo- graphs were made of both jaws and any isolated regions that were of specific interest. Each removable partial denture was classified by the arch in which it was worn and whether or not it was tooth supported, distal-extension, or a combination tooth-supported

and extension prosthesis. The r.ypc of artificial teeth, plastic or porcelain, used for each removable partial denture was recorded. The type of opposing dentition, whether natural, removable partial denture, or complete denture, was also recorded. The number and location of any intentionaliy remained roots under the prosthesis were also noted. A record was made of the number of months each removable partial denture has been worn by 1.t~ respective patient.

THE JOURNAL OF PROSTHETIC DENTJSTRY

BENSON ANT) SPOLSKY

Physical illness and medication. The patients were asked if they had any present physical illnesses and were taking any medication, and if they considered their health to be poor, fair, or good. c\lso, they were asked if their acceptance of their removable partial denture was poor, fair, or good and to make written comments regarding their prosthesis.

Oral hygiene. Disclosing solution was applied to the patient’s teeth, and the patient’s oral hygiene was rated either poor, fair, or good. A poor rating indicated visible plaque on over 7.5% of the tooth surfaces, a fair rating was plaque on 25% to 7.5% of the tooth surfaces, and a good rating was plaque on less than 25% of the tooth surfaces. A very closely scrutinized plaque index was recorded on a selected sample of the patients using the standard O’Leary plaque index.

Gingival health. The patient’s overall gingival health was evaluated, and subsequently the gingival tissues adjacent to the abutment teeth that were covered by metal at the tooth-tissue junction were examined and rated separately. For both evaluation ratings, a poor rating was used for generalized alteration in color, texture, and shape of the gingivae; a fair rating was used for moderate and intermittent changes in color, texture, and shape, while a good rating was used for generally firm, pink gingivae without alteration in the normal contour.

Tissues under denture bases. The tissues under all regions covered by the removable partial denture base were examined and rated poor if there was generalized inflammation or ulceration. A rating of fair was used if there were moderate or isolated regions of inflammation or ulceration, while a good rating was used in the absence of inflammation or ulceration.

Mobility, decay, and periodontal pockets. Each remaining tooth was evaluated for the presence of mobility, decay, or periodontal pockets. Mobility was rated from 1 to 4. A 1 rating was used for slightly visible buccal-lingual mobility, a 2 rating for visible buccal-lingual mobility, a 3 rating for visible mobility buccal-lingual and mesial-distally, and a 4 rating for visible mobility in all directions, including apical. Each tooth was examined for decay, with specific attention given to the parts of the teeth contacted by rests, retainers, or lingual plates. Periodontal pockets were identified using a standard periodontal probe and recorded in millimeters.

Existing restorations. The condition of the patient’s existing restoration was evaluated as either

poor, fair, or good. A poor rating was used if there rvert several teeth with open margins or fractured restorations, a ,fiir rating was used when only one or t\vo teeth required replacement of the existing restoration and a good rating was used when all restorations were clinically acceptable.

Framework fit, retention, and denture base stability. Each removable partial denture was examined in the mouth for framework fit to the teeth, retention. and stability of the denture base on distal-extension prostheses. Adaptation to teeth was rated poor if the removable partial denture would not seat completely or rocked, a jhir rating was used if the removable partial denture was stable but one or more occlusai rests were not completely seated on the teeth, and a rating ofgood was used for a stable prosthesis with all occlusal rests closely fitted to the teeth. Retention of the removable partial denture was also rated as poor,

,/izir, or good, but it was difficult to measure because 01‘ the relativity of the term retention. Basically. a poor rating meant there was no resistance to vertical displacment, a fair rating meant slight resistance against vertical withdrawal, and good meant moderate vertical resistance sufficient to maintain the removable partial denture in place. The stability of the denture base for all extension removable partial dentures was recorded using a scale of 0 to 3. Moderate finger pressure was placed over the extension base in a tissueward direction. A 0 score was used when there was no noticeable movement of the base toward the ridge. Tf the base was displaced about 1 mm, a score of 1 was used. A score of 2 or 3 was used when there was 2 or 3 mm, respectively, of denture base movement.

Occlusion. The patient’s centric and lateral occiu- sion was evaluated by the patient’s subjective response to occlusal prematurities both in the terminal hinge position and in a habitual position. Confir- mation of both centric and lateral contacts was verified by occlusal marking ribbons. Any occlusal slide from the terminal hinge position to the habitual biting position was rated as none, slight, moderate, or excessive, based on the extent to the slide as measured in millimeters.

Framework, occlusal wear, and maintenance. Each removable partial denture was examined for fractures of the framework and denture base> wear of the artificial teeth, and patient maintenance of the prosthesis. The occlusal wear was evaluated as slight, moderate, or excessive. Slight wear was used to indicate slight obliteration of the art&al tooth anatomy,

248 MARCH 1979 VOWME 41 NUMB&R 3

DENTURES WITH I-BAR RETAINERS

Table II. Distribution of patients examined Table III. Distribution of remov,lbic p:rti:j! by sex and age denture5 by jaw and type

Patient sex No.

Age (years)

Mean SD Range Type

ho. ----.- .-_---__--

Maxillary Mandibular TOtill

Male 39 61.3 12.4 35-86

Female 38 to.6 10.2 37-79

Total 77 60.9

while moderate and excessive wear indicated progres- sive loss of the original anatomy and tooth substance. To evaluate the patient maintenance of the prosthesis, each removable partial denture was examined before and after placing it in disclosing solution. A rating of poor showed heavy stain and calculus accumulation with plaque on over 75% of the surface, a fair rating showed moderate stain and calculus with plaque on 25% to 75% of the surface, and a good score no or little stain and less than 25% plaque.

Follow-up care. At the conclusion of each patient evaluation, the patient was informed of any definitive dental treatment that was needed and was referred to the clinic for additional treatment.

For the statistical analysis of the data, ratings of poor, fair, and good were converted into scores of 1, 2, and 3, respectively. Likewise, evaluations of slight, moderate, and excessive were converted into 1, 2, and 3 scores. respectively.

RESULTS

Number of patients. The number of patients evaluated for this study are listed in Table II by age and sex. This study was conducted annually for 7 years, and a total of 77 partially edentulous patients were examined. Forty-nine patients were seen one time, twenty-three patients were examined two times, and five patients were evaluated three times.

Removable partial denture type and length of service. The numbers of each type of removable partial denture examined in this study are listed in Table III. The mean length of time the respective removable partial dentures were worn was 3.6 years (SD = 2.4).

Opposing dentition. The type of dentition opposing the respective removable partial dentures was classified according to natural, removable partial denture? or complete denture (Table IV).

The results for the following evaluation criteria shown in Table I ( 1 to 10) are reported in Table V.

Tooth supported Extension Combination * Combinatllon.f

Total

Table IV. Distribution of dentitions opposing the removable partial dentures evaluated

Dentition No.

Natural Removable partial denture Complete denture

Total

44 .?I 00

135

Present general health Tissue under denture base

Prosthesis acceptance Existing restorations Oral hygiene Framework tit General gingival health Retention Abutment gingival Maintenancr of

health prosthesis The results for the following evaluation criteria

shown in Table I (11 to 13) are reported in Table VI.

Occlusal wear of artificial teeth. Slide from terminal hinge (centric re!ation) to

habitual occlusal position (centric occltG~n’~ Extension base displacement Occlusal prematurities. Out of a sample of 77

patients, 63 patients (81.8%) did not have occlusal prematurities, while 14 patients (18.2%‘) did demon- strate occlusal prematurities either in the- terminal hinge or habitual occlusal position.

Framework and denture base fractures. The results of the evaluation of the removable partial denture framework and denture base for the presence of fractures are reported in Table VII.

Follow-up dental treatment. Based on the clinical findings of each patient examined, the types 01 follow-up dental care that were indicated for the respective patients are listed in Table VIII. Fifteen patients had already received some type of dental

THE JOURNAL OF PROSTHETIC DENTISTRY 249

BENSON AND SPOLSKY

Table V. Frequency distribution of the results of the criteria (1 to 10) used to evaluate the various clinical conditions

Rating

---ll-.

Poor Fair Good

Condition No. % No. % No. 96

I. Present general health* I 1.3 20 26.0 56 72.7 2. Prosthesis acceptance* 11 14.3 20 26.0 46 59.7 3. Oral hygiene* 28 36.4 33 42.9 16 20.8 4. General gingival health* 12 15.6 41 53.2 24 31.2 5. Abutment gingival health* 15 19.5 34 44.2 28 36.3 6. Tissue under denture base* 6 7.8 28 36.4 43 55.8 7. Existing restorations* 4 5.2 22 28.6 51 66.2 8. Framework fit? 19 14.1 37 27.4 79 58.5 9. Retention? 34 25.2 40 29.6 61 45.2

10. Maintenance of prosthesist 27 20.0 50 37.0 58 43.0

*Based on sample of 77 patients. tBased on sample of 135 partial dentures.

treatment during the period after they had received their removable partial denture and before they were recalled for this study.

Mobility, decay, and periodontal pockets. The results of this section will be reported in part II of this study.

DISCUSSION

The results of this study should be interpreted cautiously because of the subjective nature of the evaluation criteria and with an awareness of the limitations placed on inference due to the sample size. In spite of this, the results indicate valid clinical trends and are remarkably similar to the observations of Schwalm and associates.’ The criteria used to evaluate the effects of removable partial dentures on the oral tissues provide the basis for a systematic approach to removable partial denture treatment evaluation. It is hoped that other clinicians and investigators will find the criteria useful and employ it in their own evaluative procedures.

Patient health and prosthesis acceptance. Patients had been asked to indicate what they considered to be their general health status and their acceptance of their removable partial denture. Using the Pearson Chi-square analysis to test for independence between general health status and removable partial denture acceptance, a statistically significant association (p < .05) was found between the two variables. This association between the patient’s health status and their acceptance of a removable prosthesis parallels a similar association established between the number

of yes answers on the Cornell Medical Index and complete denture satisfaction.” It is apparent that when people are experiencing health problems, their ability to adapt to removable prostheses is reduced and the prognosis will generally diminish in propor- tion of their health status. In this study, 14.8% (I 1 of 77) of the patients reported a poor acceptance of their removable partial denture. It is interesting to note that in two separate studies”, ’ that were conducted to determine what factors affect patient satisfaction with complete dentures, 12% of the patients in each study reported dissatisfaction with their dentures. Although there is an association between the patient’s health and removable partial denture acceptance, it is probable that a certain percent of patients will not be satisfied with a removable prosthesis regardless of the method of fabrication.

Oral hygiene and gingival health. By the mere fact that most partially edentulous patients have experienced tooth loss because of periodontal disease

or decay, it is reasonable to assume most of these individuals had a history of poor oral hygiene and may or may not have poor oral hygiene currently. Although each patient treated in this study received oral hygiene, dietary instructions, and definitive periodontal treatment for pocket elimination, when indicated, prior to making the removable partial denture, it is difficult to modify oral hygiene behav- ior. As shown in Table V, 79.2% (61 of 77) of the patients had either a poor or fair oral hygiene rating. These results are comparable to the problems of poor



Table VI. Frequency distribution of the results of the criteria (11 to 13) used in the evaluation process

Rating

None Slight Moderate Excessive

Condition No. % No. % No. % No. %

11. Occlusal wear of 35 25.9 41 30.4 24 17.8 35 25.9

artificial teeth* 12. Slide from termi- 53 68.8 12 15.6 10 13.0 2 2.6

nal hinge to habitual position?

13. Extension base 38 58.5 14 21.5 8 12.3 5 7.7

displaceme&

*Based on sample of 135 removable partial dentures. tBased on sample of 77 patients. IBased on sample of 65 extension removable partial dentures

patient oral hygiene reported in other studies devoted to the clinical evaluation of patients wearing removable partial dentures.‘. *-lo Brill and associates”’ reported in a study of partially edentulous patients that wearing removable partial dentures provokes a statistically significant increase in plaque formation. Bergman and associates” found that patients who have oral hygiene instruction reinforced annually in conjunction with an oral examination will not experience breakdown of the oral tissues. It is clear from the results of this study and the evidence of other investigations’, 8-*1 that patients wearing removable partial dentures must be recalled frequently and be consistently reinforced in oral hygiene cleaning procedures. Cecconi” pub- lished an extensive review of the literature on “Re- movable partial denture research and its clinical significance.” From this publication it is apparent that significant advancements have been made in analyzing and understanding the mechanical aspects of removable partial dentures. Poor oral hygiene, however, still remains the major underlying cause of removable partial denture failure.

Gingival health. The removable partial dentures evaluated in this study were designed with long guiding planes contacted by metal proximal plates that extend approximately 2 mm over the free gingival margins (Fig. 1). One of the purposes of this design is to eliminate voids at the gingival margins, thereby preventing the proliferation of hyperplastic gingival tissue. In order to evaluate the effect of the removable partial denture on the abutment gingival tissues, the overall gingival health and the gingivae

Table VII. Framework and denture bd:;e fracture*

Location NO. %

Occlusal rest <- L-i

Mafor connectori- 1 3: Acrylic resin base 4

____..-__ ,3 c *Based on samples of 135 removable partial derrurrs. tLingua1 bar.

Table VIII. Distribution of dental treatment recommended after evaluation examination

Type of treatment No. %

Denture remake Denture reline Denture repair Fixed restoration Operative restorations Periodontal surgery Endodontics Extractions Scale and polish

11 14.9

25 18.5

II 14.9

2 patients ::.6 L8 patients 24.0 2 patients 2.6 2 teeth 9 teeth

77 patients 100.0

adjacent to the abutment teeth were evaluated separately. Although the results shown in Table V indicate a slightly greater percent of poor gingival health adjacent to the abutment teeth as compared to the overall gingival health, the difference was not statistically significant (p > .05‘). Previously reported results). I*. I1 of the association between removable partial dentures and gingival inflammation are not conclusive. Carlson and associates” and Schwalm and associate9 found an increase in the inflammation of the gingival tissues approximated by the removable partial denture. Schwalm and associates’ attributed this increase in gingival inflammation as probably due to poor oral hygiene. Consistent with Schwalm and associates” explanation relating gingival inflammation and oral hygiene, Brill and associates” reported that more plaque accumulates on proximal facing surfaces than buccal surfaces. Brill and associates”’ also claimed that brushing to remove plaque was twice as effective on buccal and lingual surfaces than on mesial and distal surfaces. In this study there was a statistically significant relationship between oral hygiene and both the overall and the abutment gingival health.

There is still considerable controversy t>ver whether or not the abutment gingival tissues should be covered by the removable partial denture. In this


BENSON AND SPOLSKY

study the abutment gingivae were intimately covered by metal, whereas in other designs, such as by Krol,‘:’ the gingival tissue is totally free of metal or acrylic resin contact. It is our opinion that oral hygiene has a stronger influence on abutment gingival health than the removable partial denture design. However, based on the clinical observations and photographic records of this study, the removable partial denture design was effective in maintaining the normal gingival architecture and elimi- nating hyperplastic gingival proliferation, irrespec- tive of oral hygiene.

Tissue under denture base. The results of the assessment on the soft tissue covered by the denture base (Table V) show that 55.8% (43 of 77) of the patients were free of tissue inflammation, while the combined fair and good ratings represented 44.2% (34 of 77) of the sample evaluated. The findings are open to relative and subjective interpretation, although on a statistically significant basis the tissues supporting the removable partial denture bases were healthier than the gingival tissues. A probable explanation is that dental plaque has a greater inflamma- tory effect on tissue health than the acrylic resin base and associated occlusal load.

Existing restorations. The patients in this study had worn removable partial dentures for an average of 3.6 years, and most had not received dental care during this period of time. In consideration of the time lapse between dental treatment and the oral hygiene ratings of the patients, it is not surprising that nearly one third of the patients received poor or fair scores for their existing restorations. These results indicate a further need for removable partial denture patients to be recalled frequently.

Framework fit. As reported in Table V, 19 removable partial dentures would not seat completely or rocked. A partial explanation for the poor rating was that several patients reported wearing their prostheses only on an intermittent basis, while other patients reported dropping or otherwise bending their removable partial denture. Of the group which rated poor adaptation, 11 removable partial dentures were remade (Table VIII). The remaining removable partial dentures rated poor or fair in adaptation had sufficient stability to be clinically acceptable.

Retention. In this study the primary retention was achieved by placing I-bar retainers in O.Ol-inch undercuts. During the clinical examination it was nc ed that a large number of I-bar retainers had

moved slightly away from the undercut area due try the flexibility of the I-bar arm. Several invcstlga.

tars”“’ have shown with laboratory studies that certain retainers designs do generate significant forces against abutment teeth. According to this clinical study, the I-bar retainers generally do not create adverse forces on abutment teeth because 01 the large number of retainers that are not in tooth contact after being in service. Even without I-bar tooth contact as noted in many patients, 73.8X ( 101 of 135) of the removable partial dentures had fair to good retention because of the frictional resistance offered by long parallel guiding planes. Of the Zi.%Y (34 of 135) of the removable partial dentures with poor retention, only 5% of the patients made written comments about lack of retention.

Maintenance of prosthesis. The ratings for removable partial denture maintenance (Table V) were slightly better than the oral hygiene ratings, and yet many of the removable partial dentures had a clinically significant buildup of plaque, stain, and calculus. It is not surprising that the patients’ attention to home care of their removable partial dentures parallels their oral hygiene patterns, and this again points out the need for frequent recall.

Wear of artificial teeth. Eighty-one percent (109 of 135) of the removable partial dentures evaluated had plastic teeth for the reasons previously de- scribed. Although there was significant occlusal wear of the plastic teeth (Table VI), the amalgam centric holding stops placed in the plastic teeth appeared to be effective in maintaining occlusal contact.

Occlusal prematurities and slide-in-centric. Only 18.2% (14 of 77) of the patients evaluated demonstrated occlusal prematurities in either the terminal hinge position or the habitual closing position, and 86.8% (67 of 77) of the patients had ratings of none ro slight slide-in-centric. There are no specific criteria as to what is the optimum clinically acceptable occlusion for removable partial denture patients. It is contended that in the absence of observable or reported occlusion dysfunction, most patients had a stable, functional occlusion. These results may be attributed to a remount procedure at the placement of each removable partial denture.

Extension base displacement. Holmes“ and Leupold”’ have demonstrated with clinical studies that an altered-cast impression technique allows the least amount of denture base movement at placement and the most favorable ridge-to-denture base relationship. Although this is not a comparative



study, the results of denture base displacement Table VI) confirm the relative clinical merits of using an altered cast impression technique for extension removable partial dentures. Of the 65 extension removable partial dentures evaluated, only 13 had moderate to excessive free-end displacement after an average service of 3.6 years.

Framework and denture base fractures. All of the six occlusal rests that were fractured (Table VII) from the removable partial denture frameworks were broken over the marginal ridge at the junction of the minor connector and occlusal rest. This was probably due to insufficient reduction of the marginal ridge of the occlusal rest seat when it was opposed by an occluding cusp. The denture base fractures were primarily related to dropping the removable partial denture.

Follow-up dental treatment. Each patient that was recalled and evaluated required some type of dental treatment, from routine scaling and polishing to more definitive periodontal, prosthetic, restorative, endodontic, and surgical procedures, as indicated in Table VIII. As noted throughout this study and as cited in many of the references used, the long-term success of removable partial dentures is dependent on periodic recall of the patient and continuous maintenance of the prosthesis and the oral structures.

CONCLUSIONS

From the clinical results obtained from evaluating 77 patients treated at the UCLA School of Dentistry who had worn 135 removable partial dentures for a mean of 3.6 years, the following conclusions can be made consistent with the subjective nature of this study.

1. There was a statistically significant association 1~ < .05) between the patient’s appraisal of their general health and their acceptance of a removable partial denture.

2. Poor to fair oral hygiene was observed in most (79.2%) patients.

3. There was a statistically significant association (P < ,001) between oral hygiene and the overall gingival health, including the gingivae adjacent to the abutment teeth.

4. Even though the I-bar retainers were frequently found not to be in tooth contact, retention was generally clinically satisfactory. Long parallel guiding planes probably contribute to removable partial denture retention.

5. Patient maintenance of their rem )\ able, partial dentures was generally poor t;l i;tir

6. There was considerable ~eat of piasjic artificial teeth, but it was not clinically signific~~nt in rmms of

occlusal stability. 7. Most patients had stable o~:clusi~~n which was

attributed to a remount procedure, 8. There was a minimum of vcriical free-end

displacement with extension partial tientures that were adapted to the tissue using ai: altered-cast impression technique.

9. Insufficient reduction of the mar+nal ridge of an occlusal rest seat that is opposed b? a contacting cusp may result in fracture of tfrt rest of the framework.

10. Removable partial denture patients require frequent recall for oral hygiene instruction and periodic definitive dental treatment.

REFERENCES

1

2.

3

4.

5.

6.

7.

8.

9.

10.

11.

12.

Kratochvil, F. J., and Caputo, A A.: Photoelastic analysis of pressure on teeth and bone supporting wmovabir partial dentures. J PROSTHET DENT 32:52, 1974. Thompson, W. D., Kratochvil, F. J., and Caputo, A. A.: Evaluation of photoelastic stress patterns produced by various designs of bilateral distal-extension rrvnovable partial dentures. J PROSTHET DENT 38:261. 1977. Kratochvil, F. J.: Influence of occlusal rest position and clasp design on movement of abutment teeth ,I Pnosr~~er DENT 13:114, 1963. Schwalm, C. A., Smith, D. E., and Erickson../. I).: A clinical study of 1 to 2 years after placement of removable partial dentures. J PROSTHET DENT 38:380, 1977. Bolender, C. L., Swoope, C. C:.. and Smith. D. E.. The Cornell Medical Index as a prognostic ald for complete denture patients. J PROSTHET DENT 22:20. 1969. Smith, M.: Measurement of personality traits and their relation to patient satisfaction with c-om;&+~ dentures. J PROSTHET DENT 35:492, 1976. Langer, A. Michman, J., and Seifert, 1.: Factors influencing satisfaction with complete denturer in geriatric patienrs. ,J PROSTHET DENT 11:1019, 1961. Carlson, G. E., Hedegard, B,, and Koivumaa. ii. K.: Studies in partial denture prosthesis. IV. .4 longitudinal study of mandibular partial dentures with double extension saddles. Acta Odontol Stand 23:443, 196.5. Carlson, G. E., Hedegard, B., and Kotvumaa, K. Ii.: The current place of removable partial dentures in restorative dentistry. Dent Clin North Am 14:553, 19’70. Brill. N.. Tryde, G., Stoltze, K., and El (:hamrawy, E. A.: Ecologic changes in the oral cavity caused hy removable partial dentures. J PROSTHET DENT 389:138, 1977. Bergman, B., Hugoson, A., and Olsson, CT. 0 : Periodontal and prosthetic conditions in patients treated with removable partial dentures and artificial crowns. .A longitudinal two year study. Acta Odontol Stand 29:621. 1071 Cecconi. B. T.: Removable partial denrur- rrcearch and its


BENSON AND SPOLSKY

clinical significance. J PROWHET DENT 39:203, 1978. 13. Krol, A. .J.: Removable partial denture design. San Francis-

co, 1976, University of the pacific, School of Dentistry. 14. Firtell. I>. S.: Effect of clasp design upon retention of

removable partial dentures. J PRCWTIIET DENT 20:43. 1968.

15. Clayton, J. A., and Jaslow. C.: A measurement ufclasp forces exerted on abutment teeth. J PROSTHET DENT 25:21, 1971.

16. Shohet, H.: Relative magnitude of stress on abutment teeth with different retainers. .J PR~STHET DEST 21:267, 1969.

17. Sally, ,J.: Methods of handling abutment teeth in Class I partial dentures. J PRCXTHET DES?. 30:561, 1973.

18. Ilolmes, J. B.: Influence of impression procedures and occlusal loading of partial denture movement. ,J PKOSIH~Y DEXT 15:474, 196.5.

19. Leupold, R. .J.: A comparative study of impression proc~~- dures for distal extension removable partial denture’;. J PROWHEI. DENT 16:708, 1966.

Reprint requests lo.

DR. DAVII) bG%SOh.

UNIVERSITY OF CALIFORNIA

SCHOOL OF DENTISTRY

hi ~CELES, hLIF. 90024

ARTICLES TO APPEAR IN FUTURE ISSUES

Posterior maxillary osteotomies: An aid for a difficult prosthodontic problem John M. Alexander, D.D.S., and Joseph E. Van Sickels, D.D.S.

Temperature change caused by reducing pins in dentin Wayne W. Barkmeier, D.D.S., M.S., and Robert 1,. Cooley, D.M.D., M.S.

Surface smoothness and marginal fit with phosphate-bonded investments Joseph P. Cooney, B.D.S., MS., T. Michael Doyle, D.D.S., and Angelo A. Caputo, Ph.D.

The relationship of pattern position to the flow of gold and casting completeness Ernest DeWald, D.D.S.

Inferior joint space arthrography and characteristics of the condylar paths in internal derangements of the temporomandibular joint W. B. Farrar, D.D.S., and W. L. McCarty, Jr., D.M.D.

A clinical study of rest position using the Kinesiograph and Myomonitor James P. Geor<ge, D.D.S., M.S.D., and Malcolm E. Boone, D.D.S., M.S.D.


Download - A clinical evaluation of removable partial dentures with I-bar retainers. Part I

Top Related