The randomized shortened dental arch study: tooth loss over five years

Efficacy and risks of removable partial prosthesis in periodontitis patients: A systematic review

AIM

The aim of this systematic review was to answer the following focused question: "In partially edentulous patients with periodontitis, are removable dental prostheses (RDPs) more efficacious than no prosthetic treatment, treatment to a shortened dental arch (SDA), or tooth-supported fixed dental prostheses (FDPs)?"

MATERIALS AND METHODS

A systematic literature search was performed electronically for the period 1966-2020. Two authors independently assessed the studies for eligibility according to the PRISMA guidelines. Risk assessment was performed using RoB 2.0 and the Newcastle-Ottawa Scale.

RESULTS

Two retrospective studies indicated that RDPs increased the risk of tooth loss compared to FDPs in patients with a history of periodontitis. Prospective studies found that RDPs could be maintained without any significant periodontal destruction on a long-term basis. Owing to the heterogeneity of the data, no meta-analysis could be performed. Several studies indicated that RDP increased plaque accumulation. RDPs had only a limited effect on masticatory efficiency and nutritional status. RDPs may improve oral-health-related quality of life (OHRQoL), but to a lesser extent compared with that of patients treated to an SDA.

CONCLUSIONS

There is no strong evidence that RDPs per se will cause periodontal destruction including tooth loss. RDPs do not inevitably improve masticatory efficiency but improve OHRQoL, although less than for patients treated with FDPs including resin-bonded FDPs.

Impact of tooth loss due to periodontal disease on the prognosis of rehabilitation

When periodontal disease is diagnosed, it is difficult to predict the clinical response of treatment of a tooth over time because the result of treatment is affected by several factors and will depend on the maintenance and support of periodontal treatment. Rehabilitation with removable dental prostheses, fixed prostheses, and dental implants makes it possible to restore the function and esthetics of patients with tooth loss due to periodontal disease. The predictive factors of tooth loss in periodontitis patients should be assessed by dentists to inform their clinical decision-making during dental treatment planning. This will provide detailed individualized information and level of risk of patients considered suitable for dental rehabilitation. Therefore, the aim of this article was to review the subject of "Impact of tooth loss due to periodontal disease on the prognosis of rehabilitation" and the effect of fixed, removable, and implant-supported prostheses in periodontal patients.

Impact of shortened dental arch on oral health-related quality of life over a period of 10 years - A randomized controlled trial

OBJECTIVES

To compare oral health-related quality of life (OHRQoL) in patients with either molar replacement by partial removable dental prostheses (PRDP) or with restored shortened dental arches (SDA) over a period of 10 years.

METHODS

In this multi-center RCT, a consecutive sample of 215 patients with bilateral molar loss in at least one jaw was initially recruited in 14 prosthodontic departments. Of those patients, 150 could be randomly allocated to the treatment groups (SDA: n = 71; PRDP: n = 79), received the allocated treatment, and were available for follow-up assessments. OHRQoL was assessed using the 49-item version of the Oral Health Impact Profile (OHIP) before treatment (baseline) and at follow-ups after treatment (4-8 weeks and 6, 12, 24, 36, 48, 60, 96, and 120 months). To investigate the course of OHRQoL over time, we longitudinally modelled treatment and time effects using mixed-effects models.

RESULTS

OHRQoL substantially improved from baseline to first follow-up in both groups indicated by a mean decrease in OHIP scores of 20.0 points (95%-CI: 12.5-27.5). When compared to the SDA group, OHRQoL in the PRDP group was not significantly different (-0.6 OHIP points; 95%-CI: -7.1 to 5.9) during the study period when assuming a constant time effect. OHRQoL remained stable over the 10 years with a statistically insignificant time effect (p = 0.848).

CONCLUSIONS

For patients requesting prosthodontic treatment for their lost molars, treatments with SDA or PRDP improve clinically relevantly OHRQoL and maintain it over a period of 10 years with no option being superior to the other.

CLINICAL SIGNIFICANCE

Since there was no significant difference between the two treatment options over the observation period of 10 years, and since results have stayed stable over time, patients can be informed that both treatment concepts are equivalent concerning OHRQoL.

Biological complications of removable dental prostheses in the moderately reduced dentition: a systematic literature review

OBJECTIVES

The aim of the present study was a systematic review and subsequent meta-analysis on biological complications of removable prostheses in the moderately reduced dentition.

MATERIALS AND METHODS

A systematic literature search in established medical databases (MEDLINE, EMBASE, BIOSIS, SciSearch, Cochrane, FIZ Technik Web) and a hand search of relevant dental journals was conducted. The search terms were relevant MeSH terms, free search terms, and combinations of the two. The search included randomized controlled trials, prospective and retrospective studies with data on biological complications of removable dental prostheses in the moderately reduced dentition with at least 15 participants, an observation period of at least 2 years, and a drop-out rate of less than 25%. The selection of relevant publications was carried out at the title, abstract, and full-text level by at least two of the authors involved. The publications included were tabulated and analyzed.

RESULTS

Of the original 12,994 matches, 1923 were analyzed by title, 650 by abstract, and 111 according to the full text. A total of 42 publications were ultimately included. The following parameters were evaluated.

TOOTH LOSS

Results varied, depending on the observation period, between 0 and 18.1% for clasp-retained removable dental prostheses (RDPs), between 5.5 and 29% for attachment-retained RDPs, and between 5.5 and 51.7% for double crown-retained RDPs.

CARIES

Results varied, depending on the observation period, between 0 and 32.7% for clasp-retained RDPs, between 1.8 and 29% for attachment-retained RDPs, and between 1.8 and 16.4% for double crown-retained RDPs.

ENDODONTIC TREATMENT

Results varied, depending on the observation period, between 3.5 and 19.2% for clasp-retained RDPs, between 6.9 and 16.4% for attachment-retained RDPs, and between 0.6 and 13.9% for double crown-retained RDPs.

TOOTH FRACTURE

Results varied, depending on the observation period, between 1.7 and 5.3% for clasp-retained RDPs, between 12.7 and 40% for attachment-retained RDPs, and between 0.4 and 4.4% for double crown-retained RDPs.

TOOTH MOBILITY

There were no changes or improvements for clasp-retained RDPs. The better the pre-treatment and supportive care is, the smaller the differences are. For double crown-retained RDPs, a slight increase was found in one study. The results for the parameters probing depth and radiological bone loss were inconclusive.

GINGIVAL RECESSION

Gingival recession seemed to be favored by a mandibular sublingual bar. Compared to fixed restorations, removable restorations seemed to be associated with a more pronounced need for dental treatment. Stringent pre-treatment and supportive care reduced the complication rates.

CONCLUSIONS

Heterogeneous study designs and data analyses rendered a meta-analysis impossible, so that an evaluation at the highest level of evidence could not be performed.

CLINICAL RELEVANCE

Within the limitations of this study, it would be correct to state that removable dental prostheses require intensive maintenance. Suitable pre-treatment and supportive care can lower the complication rates, in the absence of which they constitute trigger factors for (additional) biological complications.

The randomized shortened dental arch study: influence of two different treatments on interdental spacing over 5 years

OBJECTIVES

Being a secondary outcome in a multicenter randomized controlled trial, the present analysis focused on interdental spacing in the shortened dental arch (SDA). The aim was to evaluate changes in interdental spacing in dependence of two different treatments after an observation period of up to 5 years.

MATERIAL AND METHODS

Patients were either treated with a partial removable dental prosthesis (PRDP) for molar replacement (PRDP group) or according to the SDA concept aiming at a premolar occlusion (SDA group) in a randomized manner. Interdental spacing in the anterior region was measured with gauges and categorized as "0" (<0.1 mm), "1" (<0.5 mm), "2" (0.5-1 mm), and "3" (>1 mm). The statistical analysis was performed with analysis of variance models followed by linear contrast.

RESULTS

Ninety-one patients (SDA n = 41, PRDP n = 50) were included. Changes of interdental spacing were detected in 70.7 % of all cases. A significant difference between the mean score changes was found in the mandible comparing the PRDP group and the SDA group. The respective mean score changes from baseline to 5 years were 0.23 (SD 0.49) for the PRDP group and 0.02 (SD 0.30) for the SDA group (p = 0.023).

CONCLUSIONS

Major interdental spacing could be observed in neither of the groups. The SDA concept resulted in a slightly better outcome.

CLINICAL RELEVANCE

When deciding whether to replace missing molars, the present results give further support to the SDA concept.

Process-based approach to modeling recurrent-event data explicated on the basis of occurrences of tooth losses in two different prosthetic treatment concepts

Background

In studies comparing different prosthetic treatment concepts the repeated loss of teeth was chosen as the primary outcome. The resulting data appear to represent a data structure of recurrent events. However, the application of an existing method for recurrent events is far from straightforward. Often only the first event or the final state is analyzed using Kaplan–Meier survival statistics, thereby giving a great deal of information away.

Methods

The paper presents a strategy for the analysis of recurrent data using a previously published study on the influence of different prosthetic treatment concepts for the shortened dental arch on tooth loss. A method based on cumulative sample history functions of recurrent events was adjusted for tooth loss. The shapes of these cumulative functions suggest a time dependency of the recurrence rate. To keep the model as simple as possible, a tripartite Poisson process (which assumes piecewise time-independent rates) was fitted to the cumulative mean functions stratified by treatment.

Results

Within the middle interval of the three-phasic process, the treatment effects differ significantly, which is interpreted as a delay of tooth loss due to the use of one type of prosthesis (fixed) compared with the other (removable).

Conclusions

An analysis based on cumulative history functions is based on process, therefore, temporally changing characteristics are better captured than in methods for survival analyses. The presented approach offers useful new insight into the temporal behavior of ongoing tooth loss after prosthetic treatment.

Trial registration

The trial has been registered at controlled-trials.com under ISRCTN97265367 (registration date 4 April 2008).

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1360-y) contains supplementary material, which is available to authorized users.

Tooth loss and associated factors in elders: results from a national survey in Uruguay

OBJECTIVES

This study evaluated the prevalence and severity of tooth loss in Uruguayan elders, assessing its association with demographic, socioeconomic, and behavioral factors; the use of health services; and self-reported dental treatment need.

METHODS

A population-based cross-sectional study was done among Uruguayan individuals of ages 65-74 years. Data were collected through questionnaires and clinical examinations. The dependent variable, tooth loss, was classified into three distinct outcomes: functional dentition (≥20 teeth), severe tooth loss (<9 teeth), and edentulism. The independent variables were: sex, socioeconomic status, use of health services, hypertension, diabetes mellitus, tobacco use, frequent consumption of alcohol, hygiene habits, and need for dental care.

RESULTS

The sample comprised 341 individuals, and the mean number of teeth present was 9.73 (95% confidence interval, 8.77-10.69) for each individual. After multivariate analysis, lack of a functional dentition, severe tooth loss, and edentulism were found to be associated with lower socioeconomic level, frequent consumption of alcohol, and receiving treatment from the public health system (P < 0.05). Individuals with self-reported dental treatment need had more severe tooth loss and presented a higher degree of edentulism (P < 0.05).

CONCLUSIONS

There is a high and severe prevalence of tooth loss in elderly Uruguayans, especially among those from lower socioeconomic levels. Our findings highlight the importance of public health policies to prevent and treat tooth loss.

Differences in functional outcomes for adult patients with prosthodontically-treated and -untreated shortened dental arches: a systematic review

This review examined differences in functional outcomes and patient satisfaction when shortened dental arches are left untreated compared to their restoration to complete arch lengths with different prosthodontic interventions.

METHODS

A protocol was developed according to the criteria for a systematic review. All relevant databases were searched to identify appropriate clinical trials regardless of language or publication status. Predetermined eligibility criteria were applied, trial quality assessed and data extracted for each study. Relevant outcomes assessed were: functioning ability, patient satisfaction and harmful effects on oral structures.

RESULTS

Searches yielded 101 articles: 81 from electronic databases and 20 from reference lists of retrieved articles (PEARLing searches). Sixty-nine citations were assessed for eligibility after removing 32 duplicate records. After reading titles and abstracts, a total of 41 records were excluded and the full-texts of the remaining 28 records were read. Only 21 records were included for the SR because 7 records were excluded after reading the full-text reports. These 21 records report the outcomes of four randomized controlled trials (RCTs) and one non-randomized clinical trial (CT) which were pre-specified and used for this review. No on-going studies were found and no eligible studies were excluded for failure to report the reviewer's pre-specified outcomes. Outcomes were reported in the retrieved 21 articles. A narrative explanation of the pre-specified outcomes is reported for the 3 comparison groups (which were based on the different interventions used for the individual clinical trials). The shortened dental arch as a treatment option is encouraging in terms of functioning, patient satisfaction and cost-effectiveness. By using only high quality studies it was expected that the results would be more reliable when making conclusions and recommendations, but some of the included studies had to be downgraded due to methodological errors.

Management of shortened dental arches and periodontal health: 5-year results of a randomised trial

In a multicentre randomised trial (German Research Association, grants DFG WA 831/2-1 to 2-6, WO 677/2-1.1 to 2-2.1.; controlled-trials.com ISRCTN97265367), patients with complete molar loss in one jaw received either a partial removable dental prosthesis (PRDP) with precision attachments or treatment according to the SDA concept aiming at pre-molar occlusion. The objective of this current analysis was to evaluate the influence of different treatments on periodontal health. Linear mixed regression models were fitted to quantify the differences between the treatment groups. The assessment at 5 years encompassed 59 patients (PRDP group) and 46 patients (SDA group). For the distal measuring sites of the posterior-most teeth of the study jaw, significant differences were found for the plaque index according to Silness and Löe, vertical clinical attachment loss (CAL-V), probing pocket depth (PPD) and bleeding on probing. These differences were small and showed a slightly more unfavourable course in the PRDP group. With CAL-V and PPD, significant differences were also found for the study jaw as a whole. For CAL-V, the estimated group differences over 5 years amounted to 0.27 mm (95% CI 0.05; 0.48; P = 0.016) for the study jaw and 0.25 mm (95% CI 0.05; 0.45; P = 0.014) for the distal sites of the posterior-most teeth. The respective values for PPD were 0.22 mm (95% CI 0.03; 0.41; P = 0.023) and 0.32 mm (95% CI 0.13; 0.5; P = 0.001). It can be concluded that even in a well-maintained.patient group statistically significant although minor detrimental effects of PRDPs on periodontal health are measurable.

Cost-effectiveness of tooth replacement strategies for partially dentate elderly: a randomized controlled clinical trial

OBJECTIVE

To conduct a cost-effectiveness analysis comparing two different tooth replacement strategies for partially dentate older patients, namely partial removable dental prostheses (RDP) and functionally orientated treatment based on the shortened dental arch concept (SDA).

METHODS

Ninety-two partially dentate older patients completed a randomized controlled clinical trial. Patients were randomly allocated to two treatment groups: the RDP group and the SDA group. Treatment effect was measured using impact on oral health-related quality of life (OHrQOL), and the costs involved in providing and maintaining care were recorded for all patients. Patients were followed for 12 months after treatment intervention. All treatment was provided by a single operator.

RESULTS

The total cost of achieving the minimally important clinical difference (MID) in OHrQOL for an average patient in the RDP group was €464.64. For the SDA group, the cost of achieving the MID for an average patient was €252.00. The cost-effectiveness ratio was therefore 1:1.84 in favour of SDA treatment.

CONCLUSION

With an increasingly ageing population, many patients will continue to benefit from removable prostheses to replace their missing natural teeth. From a purely economic standpoint, the results from this analysis suggest that the treatment of partially dentate older adults should be focused on functionally orientated treatment because it is simply more cost-effective.

Increased risk for premolar tooth loss in shortened dental arches

OBJECTIVES

To assess sustainability of shortened dental arches (SDA) by determining time to 'first restorative intervention' of teeth and time to 'tooth loss' and comparing these outcomes with complete dental arches (CDA) and SDA plus removable dental prostheses (RDP).

METHODS

Data (follow-up time ranged from 27.4 (SD 7.1) to 35.0 (SD 5.6) years; max. follow up: 45.8 years) from patient records of 59 subjects (23 SDA, 23 CDA, and 13 SDA plus RDP) participating in a prospective cohort study on shortened dental arches (SDA) were analysed. Group effects on survival were analysed using Cox regression models; where appropriate Kaplan-Meier analyses were done.

RESULTS

Compared to SDA subjects, CDA subjects had a lower risk to receive a first restorative intervention in anterior teeth (HR=0.377; 95% CI [0.205-0.695]) and premolars (HR=0.470; 95% CI [0.226-0.977]). CDA subjects had a lower risk to lose premolars compared to SDA subjects (HR=0.130; 95% CI [0.053-0.319]). Risk for 'first restorative intervention' and for 'tooth loss' did not significantly differ between SDA with and without RDP.

CONCLUSIONS

SDA subjects had an increased risk to lose premolars and to receive a first time restoration in anterior teeth and premolars compared to CDA subjects. SDA subjects with RDP had no increased risk to receive a first restorative intervention or for tooth loss compared to SDA without RDP.

CLINICAL RELEVANCE

Subjects with shortened dental arches can be discerned as enduring at-risk patients. It is therefore recommended that shortened dental arch subjects receive intensive and continuous care to prevent further tooth loss.

Reappraisal of the removable partial denture as a treatment option for the shortened dental arch

For patients with shortened dental arches, many treatment options are available. The existing situation can be maintained by stabilizing the present dentition and improving the occlusion without extending the arch. Alternatively, the shortened dental arch can be extended by either a free-end saddle removable partial denture, cantilevered fixed bridge, or by an implant-supported prosthesis. The free-end saddle removable partial denture can be considered a simple, non-invasive, and relatively cheap treatment option for the shortened dental arch. It was believed that such prosthodontic rehabilitation would be beneficial for the patients in terms of improving oral functions. However, the existing literature indicates that the prognosis of free-end saddle removable partial denture is not predictable, it is problematic, and its contribution to oral functions in patients with shortened dental arches is considered to be dubious. This paper reviews and summarizes the current literature about the outcome of extending the shortened dental arch by a free-end saddle removable partial denture. It also outlines factors that may affect the prognosis of this prosthetic treatment.