Treatment alternatives for the rehabilitation of the posterior edentulous maxilla

Rehabilitation of the edentulous maxilla with implant-supported fixed dental prostheses can represent a significant clinical challenge due to limited bone availability and surgical access, among other factors. This review addresses several treatment options to replace missing teeth in posterior maxillary segments, namely the placement of standard implants in conjunction with maxillary sinus floor augmentation, short implants, tilted implants, and distal cantilever extensions. Pertinent technical information and a concise summary of relevant evidence on the reported outcomes of these different therapeutic approaches are presented, along with a set of clinical guidelines to facilitate decision-making processes and optimize the outcomes of therapy.

Technical Complications of Removable Partial Dentures in the Moderately Reduced Dentition: A Systematic Review

The aim of this study was to conduct a systematic literature review with a subsequent meta-analysis on the technical complications and failures of removable partial denture (RPD) therapy in the moderately reduced dentition. A systematic literature search of established medical databases, last updated 06/2022, was conducted. RCTs and prospective and retrospective studies were included that had information on technical complications and failures of RPDs, at least 15 participants, an observation period of at least two years and a drop-out rate of less than 25%. Publications were selected on the title, abstract and full-text level by at least three of the participating authors. The evidence of the included studies was classified using the GRADE system. The bias risk was determined using the RoB2 tool and the ROBINS-I tool. Of 19,592 initial hits, 43 publications were included. Predominantly, retention of the prosthesis, retention loss of anchor crowns (decementations), fractures/repairs of frameworks, denture teeth, veneering or acrylic bases, and a need for relining were reported depending on prosthesis type and observation time. Focusing on technical complications and failures, only very heterogeneous data were found and publications with the highest quality level according to GRADE were scarce. Whenever possible, data on technical complications and failures should be reported separately when referencing the tooth, the prosthesis and the patient for comparability. Prostheses with differing anchorage types should be analyzed in different groups, as the respective complications and failures differ. A precise description of the kinds of complications and failures, as well as of the resulting follow-up treatment measures, should be given.

The Shortened Dental Arch Concept: Awareness, Knowledge, and Practice of Dentists in Dubai and the Northern Emirates, United Arab Emirates

Background and objectives. The shortened dental arch (SDA) is a dentition of no more than twenty teeth with an intact anterior region but a reduced number of occluding pairs of posterior teeth. The SDA concept is a valid treatment option in cases in which anteriors and premolars can provide adequate aesthetics, function, and occlusal stability. This study investigated dentists’ awareness and opinion of the shortened dental arch (SDA) concept among UAE dentists and its application in their practice. Methods. This is a cross-sectional study utilizing an online questionnaire anonymously to investigate the awareness and views of dentists about SDA. The questionnaire was sent to all 901 dentists registered with the Emirates Medical Association (EMA). The questionnaire consists of 17 questions, which comprise demographics, awareness, and application in dental practice, preferred treatment modality, and risks and benefits associated with SDA. The data were analyzed using SPSS Statistics. Results. The response rate reported was 40.3%. Two-thirds of the respondents (65.8%) were aware of the SDA concept; however, it was not usually applied in clinical practice (n = 196, 54.7%). Specialists were more aware of the concept ( $p\le 0.001$ ) and applied it more frequently in their clinical practice ( $p=0.041$ ) than general dental practitioners (GDPs). Respondents agreed that SDA was associated with the risks of teeth migration (n = 211, 59.9%), tooth wear (n = 196, 55.8%), and/or temporomandibular disorder (TMD) (n = 163, 45.3%). The implant was the treatment of choice for many of the participants (n = 169, 46.6%) to replace missing molars, followed by the acrylic removal partial denture (RPD) (n = 129, 35.5%). Conclusions. Most dentists who responded to this survey were aware of the SDA concept and had a positive attitude about it. However, they did not apply it frequently in their clinical practice.

Impact of oral rehabilitation on the quality of life of partially dentate elders in a randomised controlled clinical trial: 2 year follow-up

Objective

This randomised clinical trial aimed to compare the impact of two different tooth replacement strategies for partially dentate older patients namely; removable partial dentures (RPDs) and functionally orientated treatment based on the shortened dental arch (SDA) concept, on Oral Health-related Quality of Life (OHrQOL).

Methods

89 patients completed a randomised clinical trial. Patients were recruited in two centres: Cork University Dental Hospital (CUDH) and a Geriatric Day Hospital (SFDH). 44 patients were randomly allocated to the RPD group and 45 to the SDA group where adhesive bridgework was used to provide 10 pairs of occluding contacts. The impact of treatment on OHrQOL was used as the primary outcome measure. Each patient completed the Oral Health Impact Profile (OHIP-14) at baseline, 1, 6, 12 and 24 months after treatment.

Results

Both treatment groups reported improvements in OHIP-14 scores at 24 months (p<0.05). For the SDA group OHIP-14 scores improved by 8.0 scale points at 12 months (p<0.001) and 5.9 scale points at 24 months (p<0.05). For the RPD group OHIP-14 scores improved by 5.7 scale points at 12 months (p<0.05) and 4.2 scale points at 24 months (p<0.05). Analysis using ANCOVA showed that there were significant between group differences recorded in both treatment centres. 24 months after intervention the SDA group recorded better OHIP-14 scores by an average of 2.9 points in CUDH (p<0.0001) and by an average of 7.9 points in SFDH (p<0.0001) compared to the RPD group.

Conclusions

Patients in the SDA group maintained their improvements in OHrQOL scores throughout the 24 month study period. For the RPD group the initial improvement in OHrQOL score began to diminish after 6 months, particularly for those treated in SFDH. Thus, the benefits of functionally orientated treatment increased over time, particularly for the older, more systemically unwell cohort in SFDH.

Implant Placement under Existing Removable Dental Prostheses and the Effect on Follow-Up and Prosthetic Maintenance

PURPOSE

The aim of this prospective clinical study was to compare the maintenance interventions required for solely implant-retained overdentures (I-OD) with that of overdentures retained by a combination of telescopic crowns and implants (T/I-OD).

MATERIALS AND METHODS

The participants in this study were 22 patients who initially presented either with a removable complete denture (n = 11) or with an overdenture retained by 1 to 2 telescopic crowns on natural teeth (n = 11). Subsequently, the total number of abutments was increased to 5 to 6 (maxilla) or 4 to 5 (mandible) by placing implants in strategically advantageous regions, generating two distinct groups: I-OD and T/I-OD. Ball attachments were connected to the implants and integrated into the existing denture. The maintenance aspects were analyzed according to the type of treatment (preventive, biological, and technical) and to the severity of treatment (minimal, moderate, and extensive).

RESULTS

During a mean observation time of 6.5 years, the tooth survival rate was 89% (T/I-OD) and the implant survival rate 100% (both groups). The survival rates of the overdentures ranged from 90.9% (I-OD) to 100% (T/I-OD). A mean number of 0.6 (I-ODs) and 2.0 (T/I-OD) treatments were performed for biological reasons; and 8.2 (I-ODs) and 9.6 (T/I-OD) for technical reasons, per patient, during the observation time. From biological aspects, significantly more extensive maintenance was found to be necessary in the T/I-OD group than in the I-OD group.

CONCLUSIONS

The therapeutic concept of implant placement under existing prostheses was promising when performed in indicated cases.

Restoring root-canal treated molars: Cost-effectiveness-analysis of direct versus indirect restorations

OBJECTIVES

Root-canal treated molars can be directly restored, usually using resin-based-composite restorations (RBCs), or indirectly restored using full or partial crowns (FCs/PCs). Both the initial treatment costs and the risks of restorative and endodontic complications differ between RBCs and FCs/PCs. We aimed to assess the cost-effectiveness of RBCs versus FCs/PCs for restoring root-canal treated molars.

METHODS

A mixed public-private payer's perspective within German healthcare was taken. Risks of complications were extracted from large cohort studies or systematic reviews. Costs were estimated using fee-items catalogues of public and private German insurance. A Markov-model was constructed to follow up a root-canal treated molar receiving different restorations in an initially 50-year-old patient over his lifetime. Monte Carlo-microsimulations were performed to assess lifetime costs and effectiveness (tooth retention time), and the resulting cost-effectiveness.

RESULTS

RBCs were less costly than FCs/PCs (749 Euro versus 782 Euro), but also less effective (22 years versus 24 years), the incremental-cost-effectiveness-ratio was 10.80 Euro/year. This ratio increased if costs for direct restorations decreased, or costs for indirect restorations increased. If no teeth were replaced, RBC was far more cost-effective (the incremental cost-effectiveness ratios was 52.95 Euro/year). If all teeth were replaced, FC was both more effective and less costly.

CONCLUSIONS

RBCs showed lower costs, but also lower effectiveness than FCs/PCs. Consequently, the cost-effectiveness of both strategies depended on the willingness-to-pay of patients or other payers, i.e. their willingness to invest in higher effectiveness. Clinically, a large number of tooth, patient and dentist-related factors will impact on decision-making and should be considered.

CLINICAL SIGNIFICANCE

We found composite restorations to be less costly, but also less effective than indirect restorations for root-canal treated teeth. Over a long-term period, the initial treatment costs and associated cost-differences between strategies may be outweighed by costs of follow-up treatments.

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.

Is the shortened dental arch still a satisfactory option?

Aims Dental practitioners may hold the view that missing posterior teeth should be replaced to ensure a healthy masticatory system and satisfactory oral function. However, the shortened dental arch (SDA) concept is still in use, but after 35 years is it acceptable? This review searches the literature for the evidence and opinions regarding the suitability of the SDA as a current treatment modality.Methods Medline and PubMed databases were searched for relevant terms, all the abstracts were assessed and articles selected according to the pre-set exclusion and inclusion criteria.Results The search yielded 1,895 articles and after the assessment of the abstracts and application of the exclusion and inclusion criteria, 44 articles were selected for this review. These included 11 cohort studies, two longitudinal studies, two animal studies, three cross sectional studies, eight clinical studies and 18 case control studies. There appears to be a trend over the past three decades for more papers to be opposed to the SDA concept.Conclusion Evidence that the SDA causes pathology is lacking. Clinicians, healthcare authorities and patients have shown favourable attitudes towards the SDA and this continues, although there is an increase in studies opposing the concept and some are dissatisfied with this option. The concept remains viable particularly for the medically compromised patient or where restorations are considered unsuitable but further more specific studies are warranted.

The Impact of Subject Age, Gender, and Arch Length on Attitudes of Syrian Dentists towards Shortened Dental Arches

Objective. This study aimed to investigate the impact of subject age, gender, and arch length on dentists' attitudes towards unrestored shortened dental arches. Materials and Methods. 93 Syrian dentists were interviewed and presented with 24 scenarios for male and female subjects of different ages and shortened dental arches of varying length. Participants were asked to indicate on a standardized visual analogue scale how they would value the health of the mouth if the posterior space was left unrestored. Results. A value of 0.0 represented the worst possible health state for a mouth and 1.0 represented the best. The highest mean value (0.73) was assigned to a shortened dental arch with missing second molar teeth in the mouth of a 70-year-old subject. A 35-year-old female subject with an extremely shortened dental arch (all molar and premolar teeth are missing) attracted the lowest mean value (0.26). The statistical analysis indicated a significant decrease in the value placed on unrestored shortened dental arches as the number of remaining teeth decreased (p < 0.008). While subject gender had almost no impact on dentists' attitudes towards shortened dental arches, the scenarios for the older shortened dental arch subjects attracted significantly higher values compared to the scenarios for the younger subjects (p < 0.017). Conclusion. Subject age and arch length affect dentists' attitudes towards shortened dental arches, but subject gender does not.

A study of dentists' preferences for the restoration of shortened dental arches with partial dentures

OBJECTIVE

This study aimed to use a utility method in order to assess dentists' preferences for the restoration of shortened dental arches (SDAs) with partial dentures. Also, the impact of patient age and length of the SDA on dentists' preferences for the partial dentures was investigated.

MATERIALS AND METHODS

Totally, 104 subjects holding a basic degree in dentistry and working as staff members in a private dental college in Saudi Arabia were interviewed and presented with 12 scenarios for patients of different ages and mandibular SDAs of varying length. Participants were asked to indicate on a standardized visual analog scale how they would value the health of the patient's mouth if the mandibular SDAs were restored with cobalt-chromium removable partial dentures (RPDs).

RESULTS

With a utility value of 0.0 representing the worst possible health state for a mouth and 1.0 representing the best, dentists' average utility value of the RPD for the SDAs was 0.49 (sd= 0.15). Mean utility scores of the RPDs across the 12 SDA scenarios ranged between 0.35 and 0.61. RPDs that restored the extremely SDAs attracted the highest utility values and dentists' utility of the RPD significantly increased with the increase in the number of missing posterior teeth. No significant differences in dentists' mean utility values for the RPD were identified among SDA scenarios for patients of different ages.

CONCLUSION

Restoration of the mandibular SDAs by RPDs is not a highly preferred treatment option among the surveyed group of dentists. Length of the SDA affects dentists' preferences for the RPD, but patient age does not.

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.

Effect of implant-supported prosthesis on the bite force and masticatory efficiency in subjects with shortened dental arches

The aim of the study was to assess changes in bite force and masticatory efficiency in shortened dental arch (SDA) subjects rehabilitated with implant-supported restoration for 1st molar. Ten SDA subjects with bilaterally missing mandibular molars (experimental group) were recruited. In each subject, one tapered threaded implant was placed bilaterally in 1st mandibular molar region and restored. Masticatory efficiency was evaluated objectively by measuring the released dye from chewed raw carrots, with a 'spectrophotometer' at 530 nm preoperatively and at 3 months after restoration. Bite force was evaluated using 'bite force measuring appliance' preoperatively, at 6 weeks and at 3 months after restoration. Ten completely dentate-matched subjects (in terms of age, sex, height and weight) acted as control. The results revealed that as compared with the control group, the experimental group showed significantly less (P < 0.05) mean maximum bite force at pre-restoration and at 6 weeks after restoration. Although at 3 months the mean maximum bite force value was less than the control group but the mean difference was statistically insignificant. The mean difference of masticatory efficiency between control and experimental group was statistically significant (P < 0.05) before restoration, but was statistically insignificant at 3 months after restoration. Thus it was concluded that after the restoration of mandibular arch with implant-supported prosthesis, both bite force and masticatory efficiency of all SDA subjects increased and were comparable to that of matched completely dentate subjects after 3 months.

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.