A retrospective clinical evaluation of extensive tooth-supported fixed dental prostheses after 10 years

CLINICAL RESEARCH

A retrospective clinical evaluation of extensive tooth-supported fixed dental prostheses after 10 years Helena Alsterstål-Englund, DDS,a Lars-Erik Moberg, DDS, PhD,b Jenny Petersson, DDS,c and Jan-Ivan Smedberg, DDS, PhDd

ABSTRACT Statement of problem. The survival and success of tooth-supported fixed dental prostheses (FDPs) in long-term studies vary greatly, depending on the patient and the size of the FDP. Influencing factors for FDP survival or success may include advanced patient age at the time of FDP treatment, treatment severity, and use of new and cheaper FDP materials. As the patient population ages, prosthodontists will treat tooth wear in a greater number of older adults; however, recent long-term studies on such treatments are lacking. Purpose. The purpose of this retrospective clinical study was to examine extensive, tooth-supported FDPs made at 2 specialist clinics in Sweden after 10 years and to compare the outcomes with those of previous studies. Material and methods. Patients rehabilitated by using FDPs of at least 5 units at 2 specialist clinics in Sweden between 2002 and 2006 were recalled after 10 years. Clinical examinations were supplemented by reviewing clinical records and existing radiographs. Statistical analysis was performed by using the Student t test, chi-squared test, Fisher exact test, and Kruskal-Wallis test (a=.05). Results. A total of 152 patients were recalled for clinical examination. Of these, 78 patients attended and were examined. The mean age of the examined group was 70 years (range 36-94), lower than that of those not attending (80 years; range 46-100; P<.05). The mean number of units of the 78 examined FDPs was 7.3 (range 5-12) and 8.0 (range 5-14) for those not examined. FDP configurations in terms of number of units, abutments, pontics, and post-and-cores did not differ significantly between the 2 groups (P>.05). The survival proportion of the examined 78 FDPs (all units of the original FPD) was 74.4%. The success proportion (FDPs without complications) was 52.6%. The most frequent complications were caries (14.1%), endodontic complications (11.5%), loose retainers (7.7%), root fractures (5.1%), and framework fractures (3.8%). FDPs with post-and-cores (P<.05) and cantilevers (P=.054), especially when in combination (P<.05), showed more complications than FDPs without. Chipping fractures in porcelain were found in 38% of the FDPs (7.7% of the units), with more porcelain fractures on Co-Cr frameworks than on gold and titanium alloy frameworks (P<.05). Conclusions. This long-term retrospective study indicated that the prognosis for complicated and extensive FDPs in aging patients does not worsen with increased clinical complexity. New materials, treatment complexity, and older patients did not seem to markedly influence prognosis. (J Prosthet Dent 2019;-:---)

The most commonly reported complications with fixed dental prostheses (FDPs) have been caries, loss of vitality, periodontal disease recurrence, loss of retention, tooth fracture, and material fracture.1-20 The number of complications reported has varied greatly, and in a review of studies published from 1968 to 2003, the 10-year probability of FDP survival was reported to be 81%-93.8%.1

Comparing failure and success between studies is difficult because of variation in how definitions have been used and in the oral health of the patients, which changes over time. Patients retained more teeth up to an older age,21 with increasing caries and wear rates as a consequence. The bonding of composite resins to dentin has improved;22 therefore more patients receive composite

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. a Specialist in Dental Prosthetics, Department of Prosthetic Dentistry, Folktandvården Eastman Institute, Stockholm, Sweden. b Specialist in Dental Prosthetics, Department of Prosthetic Dentistry, Folktandvården Eastman Institute, Stockholm, Sweden. c Specialist in Dental Prosthetics, Department of Prosthetic Dentistry, Folktandvården South Älvsborgs Hospital, Borås, Sweden. d Specialist in Dental Prosthetics, Department of Prosthetic Dentistry, Folktandvården Eastman Institute, Stockholm, Sweden.

THE JOURNAL OF PROSTHETIC DENTISTRY

1

2

Volume

Clinical Implications Compared with pre-2000 treatments with younger patients, treatments in the early 2000s involving older patients with extensive and complex FDPs showed good survival rates.

resin restorations even though a minimal tooth structure is available for bonding.23 When bonding of composite resin restorations is inadequate to withstand mastication forces, teeth may become so severely worn that retention for FDPs is not feasible. In older patients, the need for more extensive FDPs also increases the risk of failure.5,24,25 Additionally, most long-term studies on extensive FDPs have been reported on treatments made in the 20th century. Since then, materials have changed. Gold alloys have been replaced with base metal alloys, titanium alloys, and zirconia, and zinc phosphate cement has been replaced by composite resin cements. Most studies have reported on the long-term prognosis of FDPs made by either general dentists in private practice or predoctoral students.1 Only one report was found where the treatment was performed by specialists on a referral basis between 1968 and 1973 when the patient’s dentist considered FDP treatment too complex.5 The purpose of this retrospective study was to measure the 10-year outcome of extensive FDP treatments made at 2 prosthodontic specialist clinics during the early 2000s. Patients referred to and treated at the Department of Prosthetics, Public Dental Service in Stockholm and Borås, Sweden, were recalled and examined for survival and success, and the research hypothesis was that no differences would be found when compared with studies on extensive FDP treatments in the 1960s and 1970s. MATERIAL AND METHODS Patients referred for prosthetic treatment and then treated with an FDP of at least 5 units between 2002 and 2004 (Department of Prosthetics, Public Dental Service, Stockholm, Sweden) and between 2004 and 2006 (Department of Prosthetics, Public Dental Service, Borås, Sweden) were traced 10 years after treatment by referring to the clinics’ digital records (T4, Carestream Health Inc, 2011). The 152 patients traced were sent written information regarding the study and a proposed appointment for a free clinical examination. If a patient did not confirm receiving this, they were contacted via phone calls. For the Stockholm part of the study, the ethical review board in Stockholm County deemed the study a treatment quality assessment with no need of audit and therefore returned the application (Application for Ethical Vetting, reference number 2013/293-31/3). For the Borås part, the study was approved by the local ethical review board in Göteborg

THE JOURNAL OF PROSTHETIC DENTISTRY

-

Issue

-

County and the Swedish Radiation Safety Authority (Application for Ethical Vetting, ref. no. 965-12. Research application for medical radiation, ref. no. 13-17). Clinical examinations were performed by 2 prosthodontists (H.A.E., J.P.). Before examination, the patients signed an agreement to participate in the study, and all data were anonymized. The participants were asked about follow-up treatments over the past 10 years. Extraoral and intraoral photographs and intraoral radiographs of all FDP abutments were made (Stockholm: Planmeca imaging plate and software; Planmeca. Borås: Dürr Dental imaging plate and software; Dürr Dental). Reasons for FDP replacement or modification were ascertained by asking and/or reviewing clinical records and radiographs. Survival was defined as presence of the FDP in its original state at the follow-up examination. Success was defined as presence of the FDP without biological and/or technical complications during the entire follow-up period. Carious lesions were recorded when a dental explorer could penetrate the dentin at the cervical margin of the crown or as assessed through radiographs. Loss of vitality was registered when endodontic treatment of the abutments had been made after cementation or when a periapical lesion was seen on radiographs. New periapical lesions were recorded by comparing radiographs of endodontically treated teeth with radiographs made during treatment 10 years earlier. Loss of retention was registered when mobility was detected between the FDP and the abutment, when saliva was expressed at the margin of the crown when pressure was applied, or when an explorer could easily be inserted between the tooth and the crown. Framework fracture was detected visually or through a radiograph. Tooth grinding, clenching, or excessive occlusal force was registered through clinical assessment and questioning the participants. Masticatory muscle tenderness was registered after manual palpation. Treatment with an acrylic resin occlusal device was registered. If used regularly, increasing occlusal vertical dimension (OVD) in the FDP, jaw relations according to Angle classification,26 frontal relation (normal, open, or deep occlusal relationship), occlusal position, laterotrusive and mediotrusive occlusal contacts, and antagonists of the FDP were also registered. Wear facets of all units were measured by using a millimeter graded probe, and size was graded as 0 for areas of 0-0.9 mm2, 1 for areas of 1.01.9 mm2, and 2 for areas larger than 2.0 mm2. Porcelain fractures (chipping) were registered clinically and from photographs. Cervical margins were classified in accordance with the California Dental Association (CDA) index for quality evaluation for dental care.27 The 2 examining prosthodontists were calibrated before the examination. Bleeding on probing (BoP), pocket depth >3 mm, and periodontal diagnosis of the abutments were registered clinically and on radiographs. Alsterstål-Englund et al

-

2019

3

Table 1. Number, sex, and age (years) of patients examined and not examined Not Examinedb

Examined Participants

Men

Women

All

Men

Women

Number

32

46

78

34

40

All 74

Mean agea

69

71

70

80

79

80

Standard deviation

13

11

12

11

14

13

Minimum

36

42

36

46

46

46

Maximum

88

94

94

100

97

100

a Examined patients younger than those not examined (P<.05, t test). bReasons for not attending examination were death (n=35), inability to travel, illness, weakness, lack of interest (n=37), and moved (n=2).

Table 2. Number of units, abutments, pontics, relationship between number of pontics and abutments, number of FPDs with post-and-cores, and cantilevers in original fixed dental prosthesis in examined (n=78) and not-examined (n=74) patients Examined FDP Configuration

Mean

Standard Deviation

Minimum

Not Examined Maximum

Total

FDPs

Mean

Standard Deviation

Minimum

Maximum

Total

8.0

2.4

5

14

591

78

74

Unitsa

7.3

2.3

5

12

Abutmentsa

4.7

1.7

2

10

369

4.9

1.7

2

10

365

Ponticsa

2.7

1.5

1

7

207

3.1

1.5

1

8

226

Relation pontics/ abutments

0.63

0.42

0.68

0.39

576

FDPs with post-and-coresb

45

40

FDPs with cantileversc

25

26

FDPs, fixed dental prostheses. Number of abutments and pontics and pontic-abutment relationship of FDPs for examined and not-examined groups not significantly different (P >.05, t test). b No difference between examined and not-examined patients; P >.05, Fisher exact test. cNo difference between examined and not-examined patients; P >.05, chi-squared test. a

Statistical analysis was performed by using a statistical software program (IBM SPSS Statistics, v21; IBM Corp). Comparison of continuous variables were made by using the Student t test. Contingency tables were analyzed by using the chi-squared test or Fisher exact test where appropriate. The Kruskal-Wallis test was used on periodontal parameters (a=.05). RESULTS A total of 78 participants (51.3%) were examined. They were significantly younger than those not examined (Table 1). FDP configurations in terms of numbers of units, abutments, pontics, and post-and-cores did not differ significantly between the 2 groups (Table 2). The main reason for referral and treatment at the specialist clinics was extensive prosthodontic rehabilitation, often with secondary aggravating circumstances such as extensive tooth wear with reduced tooth height and periodontal disease. Referral reasons were similar in examined and not-examined patients (Table 3, Figs. 1, 2). The FDPs of the examined patients had been provided by 17 dentists supported by 10 dental laboratories. Framework and cement materials used in the 78 FDPs are shown in Table 4. Materials used in post-andcores are shown in Table 5; 45 of the 51 FPDs with nonvital teeth had post-and-cores, mean 2.2 (standard deviation ±1.2; minimum 1, maximum 5). Regular dental evaluations were conducted by the patients’ dentists during the 10 years after treatment, sometimes in collaboration with a dental Alsterstål-Englund et al

Table 3. Referral reasons for prosthodontic treatment at specialist clinic Reasons for Referral

Examined

Not Examined

Extensive prosthodontic rehabilitation

37

54

Extensive tooth wear/bruxism

15

5

Periodontal

16

10

Allergy (gold)

4

2

Agenesis

3

1

Orthodontic

2

0

Temporomandibular disorder

1

2

Total

78

74

hygienist, except for 2 patients: 1 had not visited a dentist/ dental hygienist and 1 only for emergency purposes. The most serious complication found for an FPD in the examination and the reasons for the total loss of 10 FDPs and modification of another 10 are presented in Table 6, which also illustrates the 74.4% survival proportion. Thirty-seven (47.4%) of the 78 FDPs had at least 1 complication, with a 10-year success proportion of 52.6%. Biological complications predominated in 33.3% of the 78 FDPs, whereas the main prosthetic complications, seen in 14.1% of the FDPs, were loose retainers and framework fractures. Caries and/or composite resin restorations made during the 10 years after treatment, in 1 or more of the abutments, were registered for 26.5% of the FDPs and in 7.9% of the total 304 abutments (Table 7). Seventeen (7.7%) of the abutments initially considered to be vital showed periapical lesions at examination or had been

THE JOURNAL OF PROSTHETIC DENTISTRY

4

Volume

-

Issue

-

Figure 1. Representative patient referred for extensive prosthodontic rehabilitation because of tooth wear. A, Before treatment. B, Panoramic radiograph. C, Panoramic radiograph after treatment. D, At 10-year examination. Mandibular fixed dental prosthesis not modified.

endodontically treated during the 10 years (Table 8), and 12 of these were considered to be caused by treatment/ preparation trauma (5.4%). New periapical lesions had occurred in 11 (11.7%) of the initially endodontically treated and healthy abutments. In 2 patients, root fractures had resulted in complete FDP loss (Table 6); another patient showed modification of the FDP, and for 2 other patients, root fractures were discovered during clinical examination, which led to further modification for 1 of the FPDs (Fig. 2). Loose retainers were registered for 7 of the 78 FPDs (9%; Table 6). Three FDP frameworks (3.8%) were fractured (2 Au alloys, 1 Co-Cr alloy), 2 in patients with signs of bruxism. In 1 patient, porcelain fracture occurred after 8 years, leading to modification of the original FDP. Fourteen FDPs showed complications that could be attributed to lack of strength or to overload (tooth and framework fractures, loose retainers). Among these FDPs, those with post-and-cores and cantilevers showed more failures than FDPs with distal abutments, especially in combination (Table 9). No differences in complications were seen between different types of framework materials, cements used, tooth relations in occlusal position, jaw relations according to Angle classification (Class 1, 2, or 3), deep or open anterior occlusal position, canine protection or group function in laterotrusive movements, number of tooth contacts on the FDPs, or with regard to type of

THE JOURNAL OF PROSTHETIC DENTISTRY

opposing teeth, natural teeth, tooth-supported FDPs, implant-supported FDPs, or removable dentures (P>.05; Fisher exact test). Complications could be related to neither increased OVD nor parafunction (Table 10). Only 6 participants used their acrylic resin occlusal device regularly. Of these, 3 were both in the group with complications and in the group with parafunction. A further 2 of the 6 regular occlusal device users had increased OVD in their FDPs because of tooth wear. Of the 8 participants with loose retainers, 6 had gold and 2 had Co-Cr alloy frameworks, all cemented by using zinc phosphate cement. All FDPs had wear facets, and most units (88%) had facets larger than 1 mm (Table 11). Porcelain chipping was seen for all metal alloys used (Table 12), significantly more so for Co-Cr. The size of wear facets could not be related to the number of chipping fractures (P>.05, chi-squared test). Marginal integrity of the abutments was graded as excellent or acceptable (R and S) (Table 13) for 91.1% of the crowns. The periodontal parameters registered are presented in Table 14. One participant lost the FDP with 3 abutments because of periodontal reasons, which was 1.3% at the FDP level and 0.8% at the abutment level. DISCUSSION The survival and success in the present clinical followup study 10 years after treatment of extensive FDPs

Alsterstål-Englund et al

-

2019

5

Figure 2. Patient referred for extensive prosthodontic rehabilitation. A, Frontal view before treatment. B, Mandibular arch before treatment. C, Panoramic radiograph before treatment. D, Frontal view after treatment. E, Panoramic radiograph after treatment. F, At 10-year examination. Mandibular FDP modified with units posterior to left canine removed. G, Panoramic radiograph after examination and extraction of left mandibular canine because of root fracture and further modification of FDP. FDP, fixed dental prosthesis.

(5 units or more) between 2002 and 2006 at 2 specialist prosthetic clinics in Sweden did not show significant differences from similar studies carried out in the 1960s and 1970s. Patients had been referred from other dentists because of complicated prosthodontic treatment, where the difficulties presented were a large extension

Alsterstål-Englund et al

of the FDP and often with additional aggravating circumstances such as heavily damaged teeth or periodontal disease. Seventy-eight of the 152 patients called for examination attended (51%). Both higher and lower attendance (29% to 88%) have been reported in long-term follow-up

THE JOURNAL OF PROSTHETIC DENTISTRY

6

Volume

Table 4. Material used in frameworks of the 78 examined fixed dental prostheses and cements for definitive cementation Material

Manufacturer

High precious gold alloy (n=49)

Sjödings KarAna

Co-Cr alloya (n=16)

BEGO

Harvard zinc phosphate cement (n=14) Fuji Plus Cem (n=1)g Multilink Automix (n=1)h

Titanium alloy (n=6)

Sjödings KarAna

Harvard zinc phosphate cement (n=6)

Zirconiab (n=2)

Decim AB

RelyX Unicem (n=1)i Panavia (n=1)j

Not knownc (n=5)

Harvard zinc phosphate cement (n=4) RelyX Unicem (n=1)

a

Wirobond C. bDenzir. cMetal alloys. dHarvard Dental International GmbH. e3M ESPE. fBisco Inc. gGC Corp. hIvoclar Vivadent AG. i3M ESPE. jKuraray Dental Inc.

studies (>10 years).2,6-8 In the present study, attendance appeared age-related: mean attending 70 years (range 3694) and mean not attending 80 years (range 46-100). Different outcomes in the higher age not-examined group cannot be excluded, as there may be other prognosis indicators and estimates.3-5 In older patients, using abutments with poorer prognosis could be a calculated risk, which could increase the risk for failure.7 However, no significant differences were seen in the reasons for treatment referral in the 2 groups, in the number of FDPs with post-and-cores and cantilevers, or the number of and relationships between pontics and abutments, which in both groups fell within the range of other studies.1 Twenty FDPs were completely lost or modified at the time of examination, giving a 10-year survival rate of 74.4%. The most frequent reasons for FDP loss or modification were caries, endodontic complications, root fractures, loss of retention, and fracture of framework, which were similar to those of earlier reports.5,9-11 Both lower and higher survival proportions have been reported: lower after longer follow-up times and higher when studies had a greater number of younger patients and shorter FDPs, both shown previously to increase FDP survival.1,3-5,10,13,14 In the present study, taking into account all biological and prosthetic complications, such as caries and composite resin restorations, endodontics, fractured roots, loose retainers, and porcelain fracture, 37 of the 78 FDPs (47.4%) were affected by at least one of these, giving a success rate of 52.7% after 10 years. The criteria for success differ greatly among studies, and complications such as caries and pulpal disease are sometimes not included.1,2,4-15 Complications will therefore be discussed separately and compared with those reported in other studies. During the 10 years, 26.5% of the FDPs examined had developed caries, excluding FDPs with caries in abutments with loose retainers, which falls within the range reported in other long-term studies.9,11,15 Three of 78 FDPs (4.4%)

THE JOURNAL OF PROSTHETIC DENTISTRY

Issue

-

Table 5. Number of abutments and FDPs with vital and nonvital teeth with different kinds of posts in original 78 FDPs Post Material

Cement Harvard zinc phosphate cement (n=47)d Ketac Cem Glass Ionomer Cement (n=1)e All bond C&B cement (n=1)f

-

Vital Teeth

Nonvital Teeth

Abutments (n)

251

118

80

5

FDPs (n)

74

51

36

3

Unit

ScrewPost

Total Posts

14

1

100

12*

1

45

Gold Titanium Fiber

FDPs, fixed dental prostheses. *In 7 FDPs in combination with gold alloy posts.

had been reduced because of caries, which is near a calculated 10-year reported risk of 2.6%.1 On the abutment level, 7.9% had developed caries, also near a calculated 10-year risk of 9.5%.1 However, the incidence of caries reported varies greatly between 0.7% and 23%.6,7,9 Periapical lesions were seen in 7.7% of the teeth considered vital at cementation. Treatment trauma was the only explanation found in 5.4% of the lesions, a low percentage compared with the findings of other reports.1,5-7,9 The endodontically treated teeth examined showed 11.7% periapical lesions, which is also lower than that in earlier reports.6,7,28 This difference may be because endodontic treatment was conducted mostly by endodontic specialists at the clinic. Four of 5 root fractures appeared in roots with posts, possibly because nonvital teeth can withstand greater stress before marked discomfort or pain sensations appear, increasing the risk for overload.9,16 Loose retainers (9.0%) and framework fracture (3.8%) were comparable with those in earlier reports.1,5,6,9 In FDPs with complications attributed to lack of strength or because of overload, more failures were found when posts were present in the FDP (26.7%) compared with when only vital abutments were present (6.1%), and more failures were also seen for cantilever FDPs (32.0%) than for FDPs with distal abutments (11.3%), especially in combination with posts (46.7%). These frequencies are relatively high, possibly because of a relatively large extension of FDPs and relatively old patients.2,7,11-13,16,29 In this small patient group, increased risk of failure could not be related to any single parameter such as type of framework material or cement used, opposing teeth, increased OVD, parafunction, and jaw or tooth relations in occlusion or articulation. However, 3 of 6 patients using their acrylic resin occlusal devices regularly were found both in the group with complications because of overload and in the group with parafunction, while 2 also had increased OVD because of heavy tooth wear, both of which are risk factors for complications. Previous extensive tooth wear could not be related to the number or size of facets or the number of chipping fractures in the present study. However, more FDPs with Co-Cr frameworks not only had chipping fractures but also a larger number of fractures than the other framework materials. It is possible that Co-Cr had been chosen for strength reasons, as 4 of the 8 patients with chipping fractures were in

Alsterstål-Englund et al

-

2019

7

Table 6. Most serious FDP complications registered for 78 participants examined after 10 years and main complications responsible for total loss and modification of FDPs Modification of FDPd Loss of FDP (n) (n)

Total (n)

FDP at Examination (n)

Caries/composite resin restoration

11

8a

Endodontic

9

6

2

Root fracture

4

1b

1

Overloading/periodontal

1

1

2.7

1.3

Others

1

1

2.7

1.3

Total biological

26

70.2

33.3

Type of Complication

Percentage of Complications (%)

Percentage of FDPs With Complication (%)

29.7

14.1

1

24.3

11.5

2

10.8

5.1

Biological 3

Prosthetic 2c

Loose retainers

6

1

3

16.2

7.7

Framework fracture

3

2

1

8.1

3.8

Porcelain fracture

1

1

Phonetic

1

Total prosthetic

11

Total

37

17

10

2.7

1.3

1

2.7

1.3

29.8

14.1

10

100.0

47.4

FDP, fixed dental prosthesis. FDPs with caries in loose retainers and earlier complications in reduced and lost FDPs not included. One FDP with root fracture at examination not included because of earlier complication with loose retainer. cAnother 2 FDPs were loosened but had previously been registered as reduced from caries and loosening. dComplications in remaining FDPs shown in following sections. a

b

Table 7. Number of FDPs and abutments with caries and composite resin restorations registered (% in parentheses) Unit

Total

Caries

Composite Resin Restorations

FDPs

68

12 (22.1)a

3 (4.4)

Abutments

304

20 (6.6)b

4 (1.3)

Table 9. Number of FDPs with distal abutments and with cantilevers, with and without posts, and number of complications due to overload (% in parenthesis)

Group

Post

b

Without Post

FDPs With Cantilevera b

Postb

Endodontically Treated Abutments

Initially Vital Abutments

FDPs, fixed dental prostheses. aCaries in loose retainers of 4 FDPs excluded. bCaries in 9 loose retainers excluded.

FDPs With Distal Abutmentsa

Table 8. Number of initially vital and endodontically treated abutments with periapical lesions registered (% in parentheses)

Without Postb

Total

30 (100)

23 (100)

15 (100)

10 (100)

Complications

5 (16.7)

1 (4.3)

7c (46.7)

1c (10.0)

FDPs, fixed dental prostheses. aComplications in FDPs with cantilevers compared with distal abutments not significant: P=.054, Fisher exact test. bMore complications in FDPs with posts compared with without posts: P<.05, Fisher exact test. cMore complications in cantilever FDPs with posts than without posts: P<.05, Fisher exact test.

Total

Periapical Lesion

Total

Periapical Lesion

222

17 (7.7)a

94b

11 (11.7)

a

Three loose retainers and 2 abutments with caries. bTwenty-four initially endodontically treated teeth at cementation not registered at examination because other treatments had been performed or teeth had been extracted.

Table 10. Proportion of 78 participants with increased OVD in FDPs, with parafunction, who had received acrylic resin occlusal device after prosthodontic treatment and using device regularly and number of participants with complications in FDPs from overload (% in parentheses) for respective groups

Category No. of patients

Using Occlusal Device Regularly

Increased Received Acrylic OVD in Resin Occlusal Total FDP Parafunction Device 78

Complications*14 (18)

16

19

15

6

4 (25)

4 (21)

4 (27)

3 (50)

FDP, fixed dental prosthesis; OVD, occlusal vertical dimension. *No significant differences in complications between groups: P >.05, Fisher exact test.

Table 11. Distribution and size of wear facets in 482 units examined Index

Table 12. Number of different framework materials in examined FDPs (n=68) and number of chipping fractures

Condition

0

1

2

Total

Facets (n)

58

229

195

482

Condition of FDP

Au

Co-Cr

Ti

Zi

Not Knowna

Percent

12

48

40

100

FDPs

49

16

6

2

5

78

FDPs with chipping fractures

17

8b

1

0

0

26

Total no. of chipping fractures

22

14

1

0

0

37

the group referred because of heavy tooth-wear/bruxism and the porcelain became the weak part of the FDPs. Only 1 porcelain fracture occurred, which necessitated remaking a part of the FDP; however, 33% of the patients showed at least 1 chipping fracture, which is more than that reported in earlier similar studies.2,6 In recent years, greater focus has

Alsterstål-Englund et al

Total

FDPs, fixed dental prostheses. Unknown metal-ceramic alloy. Co-Cr FDPs showed more chipping fractures than other FDPs: P<.05, Fisher exact test. a

b

been on porcelain chipping, and recent reports have shown relatively high incidences.19,20,29-31 Parafunction has been reported to increase chipping,20 but in the present study,

THE JOURNAL OF PROSTHETIC DENTISTRY

8

Volume

Table 13. Marginal integrity of 304 examined crowns according to CDA rating system CDA Index Crown

R

S

Ta

Vb

Total

Number

99

178

18

9

304

Percent

32.5

58.6

5.9

3.0

100

CDA, California Dental Association. retainers.

a

Caries or composite resin restorations. bLoose

Table 14. BoP (%) of abutments for 68 participants examined, maximum gingival pocket depth of abutment and most aggravated periodontal diagnosis of abutment

BoP

Maximum Gingival Pocket Depth (mm) No.

%

No.

%

e20

37

54.4

<4

8

11.8

Periodontal Diagnosis No.

%

Levis

45

66.2

21-50

14

20.6

4-6

56

82.3

Gravis*

22

32.3

51-80

9

13.2

7-9

4

5.9

Complex*

1

1.5

81-100

8

11.8

Total

68 100.0

68 100.0

68 100.0

BoP, bleeding on probing. Ten of the original 78 participants lost their FDPs, maximum gingival pocket depth of abutment, and most aggravated periodontal diagnosis of abutment. *Patients with gravis and complex diagnoses showed significantly larger maximum pocket depth of abutments than patients with Levis diagnosis: P<.05, nonparametric Kruskal-Wallis test.

parafunction activity alone could not be related to the presence of chipping fractures. The margins were rated good or acceptable in 91.1% of the abutments, which is high compared with that in earlier long-term reports.6,19 Only 1 of the 78 FDPs (1.3%) was lost for periodontal reasons, which implies that the periodontal condition of patients from a prosthetic aspect may be considered as relatively good.1,5,6 CONCLUSIONS Based on the findings of this long-term clinical study, the following conclusion was drawn: 1. The prognosis for complex and extensive FDPs in aging patients does not worsen with the accompanying increase in clinical complexity compared with treatments of younger patients reported in the past.

-

Issue

-

7. Walton TR. An up to 15-year longitudinal study of 515 metal-ceramic FPDs: Part 1. Outcome. Int J Prosthodont 2002;15:439-45. 8. Bart I, Dobler B, Schmidlin K, Zwahlen M, Salvi GE, Lang NP, et al. Complication and failure rates of tooth-supported fixed dental prostheses after 7 to 19 years in function. Int J Prosthodont 2012;25:360-7. 9. Randow K, Glantz P-O, Zöger B. Technical failures and some related clinical complications in extensive fixed prosthodontics. Acta Odontol Scand 1986;44: 241-55. 10. Glantz P-O, Nilner K, Jendresen MD, Sundberg H. Quality of fixed prosthodontics after 15 years. Acta Odontol Scand 1993;51:247-52. 11. Libby G, Arcuri MR, LaVelle WE, Hebl L. Longevity of fixed partial dentures. J Prosthet Dent 1997;78:127-31. 12. De Backer H, Van Maele G, De Moor N, Van den Berghe L, De Boever J. A 20-year retrospective survival study of fixed partial dentures. Int J Prosthodont 2006;19:143-53. 13. Scurria MS, Bader JD, Shugars DA. Meta-analysis of fixed partial denture survival: prostheses and abutments. J Prosthet Dent 1998;79:459-64. 14. Pjetursson BE, Tan K, Lang NP, Brägger U, Zwahlen M. A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. IV. Cantilever or extension FPDs. Clin Oral Implants Res 2004;15:667-76. 15. Valderhaug JV. Periodontal conditions and carious lesions following the insertion of fixed prostheses: a 10-year follow-up study. Int Dent J 1980;30: 296-304. 16. Randow K, Glantz P-O. On cantilever loading of vital and non-vital teeth. An experimental clinical study. Acta Odontol Scand 1986;44:271-7. 17. De Backer H, Van Maele G, Decock V, Van den Berghe L. Long-term survival of complete crowns, fixed dental prostheses, and cantilever fixed dental prostheses with posts and cores on root canal-treated teeth. Int J Prosthodont 2007;20:229-34. 18. Torbjörner A, Karlsson S, Ödman PA. Survival rate and failure characteristics for two post designs. J Prosthet Dent 1995;73:439-44. 19. Eliasson A, Arnelund C-F, Johansson A. A clinical evaluation of cobaltchromium metal-ceramic fixed partial dentures and crowns: three-to sevenyear retrospective study. J Prosthet Dent 2007;98:6-16. 20. Koenig J, Vanheusden AJ, Le Goff SO, Mainjot AK. Clinical risk factors related to failures with zirconia-based restorations: an up to 9-year retrospective study. J Dent 2013;41:1164-74. 21. Eklund SA. The impact of improved oral health on the utilization of dental services. J Dent Educ 2017;81:eS110-9. 22. Sofan E, Sofan A, Palaia G, Tenore G, Romeo U, Migliau G. Classification review of dental adhesive systems: from the IV generation to the universal type. Ann Stomatol 2017;8:1-17. 23. Milosevic A, Burnside G. The survival of direct composite restorations in the management of severe tooth wear including attrition and erosion: a prospective 8-year study. J Dent 2016;44:13-9. 24. Zidan O, Ferguson G. The retention of complete crowns prepared with three different tapers and luted with four different cements. J Prosthet Dent 2003;89:565-71. 25. Foster L. The relationship between failure and design in conventional bridgework from general dental practice. J Oral Rehabil 1991;18:491-5. 26. Angle EH. Classification of malocclusion. Dent Cosmos 1899;41:248-64. 27. California Dental Association. Quality evaluation for dental care. Guidelines for the assessment of clinical quality and professional performance. Los Angeles: The California Dental Association; 1977. p. 53-5. 28. Ng Y-L, Mann V, Gulabivala K. Outcome of secondary root canal treatment: a systematic review of the literature. Int Endod J 2008;41:1026-46. 29. Heintze SD, Rousson V. Survival of zirconia- and metal-supported fixed partial prostheses: a systematic review. Int J Prosthodont 2010;23:493-502. 30. Sailer I, Gottner J, Känel S, Hämmerle CH. Randomized controlled clinical trial of zirconia-ceramic and metal-ceramic posterior fixed dental prostheses. A 3-year follow-up. Int J Prosthodont 2009;22:553-60. 31. Anusavice KJ. Standardizing failure, success, and survival decisions in clinical studies of ceramic and metaleceramic fixed dental prostheses. Dent Mater 2012;28:102-11.

REFERENCES 1. Tan K, Pjetursson BE, Lang NP, Chan ESY. A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. III. Conventional FPDs. Clin Oral Implants Res 2004;15:654-66. 2. Näpänkangas R, Salonen-Kemppi MAM, Raustia AM. Longevity of fixed metal ceramic bridge prostheses: a clinical follow-up study. J Oral Rehabil 2002;29:140-5. 3. Karlsson S. Failures and length of service in fixed prosthodontics after longterm function. Swed Dent J 1989;13:185-92. 4. Valderhaug JV. A 15-year clinical evaluation of fixed prosthodontics. Acta Odontol Scand 1991;49:35-40. 5. Palmqvist S, Swartz B. Artificial crowns and fixed partial dentures 18 to 23 years after placement. Int J Prosthodont 1993;6:279-85. 6. Karlsson S. A clinical evaluation of fixed bridges, 10 years following insertion. J Oral Rehabil 1986;13:423-32.

THE JOURNAL OF PROSTHETIC DENTISTRY

Corresponding author: Dr Helena Alsterstål-Englund Department of Prosthetic Dentistry Folktandvården Eastman Institute Box 6031 S-102 31 Stockholm SWEDEN Email: [email protected] Acknowledgments The authors thank Dr Victoria Franke Stenport, DDS, PhD, University of Gothenburg, for her guidance in planning and the support that she provided throughout the study. Copyright © 2019 by the Editorial Council for The Journal of Prosthetic Dentistry. https://doi.org/10.1016/j.prosdent.2019.10.009

Alsterstål-Englund et al