Randomised multicentre study of prosthetic treatment options for shortened dental arch: pilot trial

ISRCTN ISRCTN68590603
DOI https://doi.org/10.1186/ISRCTN68590603
Secondary identifying numbers DFG WA 831/2-1 to 2-6
Submission date
07/03/2008
Registration date
21/04/2008
Last edited
20/04/2010
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Oral Health
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Prof Michael Walter
Scientific

Fetscherstr. 74
Dresden
01307
Germany

Phone +49 351/458 2706
Email Michael.Walter@uniklinikum-dresden.de

Study information

Study designMulti-centre randomised controlled clinical trial.
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Not specified
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific title
Study acronymSDAS - pilot
Study objectivesOver the last 20 years a mechanistic attitude correlated with a lack of longitudinal controlled randomised trials regarding the question of prosthetic treatment after tooth loss. The need assessment considered the replacement of all missing teeth by fixed or removable partial dentures or dental implants as a necessity especially in cases of shortened dental arches. Modern prosthetic concepts distinguish between different dimensions of need (normative need, perceived need) being well aware of the fact that perceived need has been under-represented in the past. An innovative sight puts a higher emphasis to the subjective components of need assessment and outcome measurement. Generally three adverse effects of non-replacement of molars were postulated: temporomandibular joint (TMJ) disorders, tooth migration/overeruption, insufficient chewing ability. However, no evidence based on randomised trials has been provided concerning the incidence of the adverse side effects mentioned above, nor is there high-level evidence regarding a benefit of removable dentures for molar replacement. On the contrary removable partial dentures are compromised by a high incidence of adverse side effects such as plaque accumulation and peridontal breakdown.

Among therapeutic alternatives, an approach with a limited restoration goal focused on incisors, canines and premolars (shortened dental arch [SDA] concept) has been described and implemented although discussed controversially. Within this concept, fixed partial dentures are used for tooth replacement of which a superior performance compared with removable partial dentures has been reported. The multicentre study was initiated in 2000 because evidence was lacking concerning the benefit of different therapeutic options regarding the preservation of oral health, oral health related quality of life, patients satisfaction, absence of discomfort, satisfactory chewing ability and aesthetic satisfaction. Public health aspects of the study lie in the fields of health economics, avoidance of over-treatment, and therapy guidelines on a population based level.

Two prosthetic therapy arms will be compared:
1. The replacement of posterior teeth at last up to the first molar by removable partial dentures
2. Prosthetic treatment according to the shortened dental arch concept. To avoid removable partial dentures, posterior teeth are replaced up to the second premolar by fixed restorations, if necessary. Molars are not replaced.

The aim of this trial is to test the hypothesis that the treatment outcome varies depending on the treatment concept (fixed versus removable prostheses) in the therapy of patients with missing molars.

Please note that the pilot phase of this trial has been completed. Details of the full trial may be found at http://www.controlled-trials.com/ISRCTN97265367
Ethics approval(s)Ethics Committee of the Medical Faculty of the Technical University of Dresden (Ethikkommission der Medizinischen Fakultät der Technischen Universität Dresden). Date of approval 19/04/1999 (ref: EK 260399)
Health condition(s) or problem(s) studiedTooth loss/ molar replacement
InterventionControl group (Therapy A): The molar replacement by removable partial dentures, carried out using fixed crowns and bridges as anchor for removable dentures

Intervention group (Therapy B): Restorations according to the SDA concept, with only fixed restorations or no restoration at all. The maximum extension reached up to the second premolar, and no molars were replaced. All restorations were made according to a standardized procedure (SOP) given by the study protocol.

Standard gold alloys and dental ceramics were used for fixed restorations, base metal alloys for the removable denture frameworks.
Intervention typeOther
Primary outcome measureFurther tooth loss. Duration of follow-up: 5 years
Secondary outcome measuresThe following were assessed at baseline (4-8 weeks after insertion), 6 month, then annually from Year 1 to 5:
1. Clinical:
1.1. Crown/root caries
1.2. Abrasion (Index 0-4)
1.3. Interdental spacing in the anterior region (Index 0-3)
1.4. Sensibility (+/-)
1.5. Periodontitis/Gingivitis: Plaque-index (index 0-3), probing depth (6 point measurement in mm), attachment loss (6 point measurement in mm), gingival index(index according to Sillnes and Loe: 0-3), bleeding on probing (BOP)(+/-), tooth mobility (index 0-3) , mucosa lesions (California Dental Association [CDA] Criteria)
2. Clinical dysfunction index (Helkimoindex): Muscle pain via palpation (m. masseter pars profunda et superficialis, m. temporalis pars posterior et anterior,m. suboccipitalis, m. sterno-cleidomastoideus, m. pterygoideus medialis et lateralis, t. temporalis)
2.1. Range of movement (mm): maximal opening, maximal lateral movements, maximal protrusion
2.2. TMJ function: Description of pain on movement/path of movement, palpation/auscultation
3. Technical (according to the CDA criteria): Treatment performance, preparation form, marginal fit, occlusion static/dynamic im µm, proximal contacts (shape/ strength)
4. Technical performance (according to the CDA criteria): Evaluation of used materials, prosthesis and bridge design, saddle extension, attachment performance, possibility of dental hygiene
5. Aesthetics (according to the CDA criteria): rated by the dentist, surface, color, translucency, contour
6. Ridge reduction: (x-ray examination according to Steen )

Subjective:
7. Oral health related quality of life (OHIP-Questionnaire): Measure of self reported dysfunction, discomfort and disability attributed to oral conditions
8. Dworkin Index Axis II (questionnaire): Assessment of psychological distress and psychosocial dysfunction including questions regarding:
8.1. Graded chronic pain severity
8.2. Depression
8.3. Vegetative symptoms and somatization subscales of the SCL-90-R developed by Derogatis and others
8.4. Jaw disability checklist

The CDA Criteria are used according to the Guidelines for the Assessment of Clinical Quality and Professional Performance of the California Dental Association: http://www.cda.org/library/cda_member/policy/quality/quality.html
Overall study start date01/10/2000
Completion date26/11/2007

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants72
Key inclusion criteria1. Patients over 35 years of age, male and female
2. Those who requested prosthetic treatment with a minimum dentition of both canines and one premolar per side preserved in at least one jaw (Kennedy class I). A dentition including all anterior teeth up to the second premolar on both sides in one jaw was defined as maximum
3. Rejection of implant treatment by the patient
4. Patients with general health according to American Society of Anesthesiologists (ASA) classification group one ore two
5. All abutment teeth must be free of periodontal disease (pocket depth less or equal 4 mm, tooth mobility <= grade 2, mean plaque index <= grade 2, bleeding on probing at all teeth <=25 %) and caries
6. Caries free adjacent teeth
7. Sufficient treatment of the opposite jaw, extending the dentition depending on the randomized treatment option up to the second premolar or the first molar
Key exclusion criteria1. Patients with alcohol or drug addiction
2. Mentally disordered patients
3. Patients with TMJ disorders
4. Dysgnathic patients with Angle class II or III
5. Patients who have received or need orthodontical treatment
6. Patients who have been already sufficiently treated
7. Patients who do not accept a removable deture
8. Patients who demand the replacement of all molars
9. Patients with general health American Society of Anesthesiologists (ASA) classification group four
Date of first enrolment01/10/2000
Date of final enrolment26/11/2007

Locations

Countries of recruitment

  • Germany

Study participating centre

Fetscherstr. 74
Dresden
01307
Germany

Sponsor information

German Research Foundation (Deutsche Forschungsgemeinschaft) (Germany)
Government

Kennedyallee 40
Bonn
53175
Germany

Phone +49 228/885 1
Email postmaster@dfg.de
Website http://www.dfg.de
ROR logo "ROR" https://ror.org/018mejw64

Funders

Funder type

Government

German Research Foundation (Deutsche Forschungsgemeinschaft) (Grant ref: WA 831/2-1 to 2-6) (Germany)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 01/11/2005 Yes No