Immediate versus delayed loading of strategic mini dental implants for the stabilization of partial removable dental prostheses: a patient cluster randomized, parallel-group 3-year trial

Effect of surgical and prosthodontic protocols of distal extension implant-supported removable partial dentures on clinical and patient-reported outcomes: A systematic review

STATEMENT OF PROBLEM

Standard surgical and prosthodontic protocols for managing partially dentate patients with implant-supported removable partial dentures (ISRPDs) are lacking.

PURPOSE

The purpose of this systematic review was to determine clinical and patient-reported outcome measures (PROMs) in patients provided with ISRPDs in distal edentulous arches based on different surgical and prosthodontic protocols.

MATERIAL AND METHODS

An electronic and manual literature search was conducted in 3 databases, PubMed/MEDLINE, SCOPUS, and Cochrane Library, for clinical studies on distal extension ISRPDs related to clinical and patient-reported outcomes. Kennedy Class I and II arches described in articles published from January 2000 to December 2023 were included. Clinical parameters regarding implant type, location, loading protocols, and implant survival rate and PROMs including masticatory performance, esthetics, and overall satisfaction were compared. The risk of bias was determined by using the Cochrane Risk of Bias Tool 2.0 (RoB 2.0).

RESULTS

An initial total of 103 studies were identified, but only 11 articles were selected after implementing the inclusion and exclusion criteria. Ten studies evaluated PROMs, and 6 studies evaluated clinical outcomes (5 studies evaluated both). The implant survival rate ranged from 91.7% to 100%, with no clear differentiation among the studies with immediate or delayed loading protocols. Most studies described implants positioned in the molar region. In general, patient satisfaction and oral health-related quality of life (OHRQoL) improved significantly with ISRPDs compared with conventional removable partial dentures (RPDs) or RPDs with healing abutments. Posttreatment clinical outcomes revealed stable peri-implant health with no significant bone loss or prosthetic complications. No specific implant configuration, including implant type and location or attachment system, appeared to be better than another. Ball attachments were the commonly used attachments. Two studies were of high risk and 3 studies of low risk. The remaining 6 studies were judged to have some concerns based on the RoB 2.0 analysis.

CONCLUSIONS

Providing an ISRPD improved patient satisfaction, OHRQoL, and the clinical outcomes in distal extension situations, with most studies positioning the implants in the molar region. The type of attachment did not significantly affect the outcomes, although ball attachments were the most used attachment in ISRPDs.

The intra- and inter-rater reproducibility of bone level measurements at strategic mini-implants using dental panoramic radiography

OBJECTIVES

This experimental study focused on the intra- and inter-rater reproducibility of vertical bone level (VBL) measurements at strategic mini-implants (MI) using digital panoramic radiographs (PR).

STUDY DESIGN

VBLs of 152 MIs for removable partial denture stabilization at 50 randomly chosen PRs from a clinical trial were digitally evaluated by three ratters. Rater deviations exceeding 0.5 mm were re-examined. The intra-class correlation coefficient (ICC) was applied to estimate reliability. The smallest detectable change (SDC) was interrelated to the minimal clinically important change of 0.2 mm.

RESULTS

The first measurement round revealed intra- and inter-rater ICCs of > 0.8. However, 28 sites (9 %) were unreadable, and 97 sites (32 %) revealed differences between observers of ≥ 0.5 mm. Following a consensus session and re-training, an additional 8 sites were excluded and all remaining VBL differences were ≤ 0.5 mm. Thus, the SDCs with 95 % credibility were improved from 0.73 to 0.31 mm in the intra-rater and from 1.52 to 0.34 mm in the inter-rater statistics. Given a 50 % credibility for this special setting, both the intra- and inter-rater SDCs were 0.11 mm.

CONCLUSIONS

Digital PR can be reliably utilized to determine VBLs around MIs under conditions of at least two trained observers, mutual calibration sessions, and exclusion of unquantifiable radiographs.

GERMAN CLINICAL TRIALS REGISTER ID

DRKS00007589, www.germanctr.de.

Survival and stability of strategic mini-implants with immediate or delayed loading under removable partial dentures: a 3-year randomized controlled clinical trial

Objectives

Stability values of mini-implants (MIs) are ambiguous. Survival data for MIs as supplementary abutments in reduced dentitions are not available. The aim of this explorative research was to estimate the 3-year stability and survival of strategic MIs after immediate and delayed loading by existing removable partial dentures (RPDs).

Material and methods

In a university and three dental practices, patients with unfavorable tooth distributions received supplementary MIs with diameters of 1.8, 2.1, and 2.4 mm. The participants were randomly allocated to group A (if the insertion torque ≥ 35 Ncm: immediate loading by housings; otherwise, immediate loading by RPD soft relining was performed) or delayed loading group B. Periotest values (PTVs) and resonance frequency analysis (RFA) values were longitudinally compared using mixed models.

Results

A total of 112 maxillary and 120 mandibular MIs were placed under 79 RPDs (31 maxillae). The 1st and 3rd quartile of the PTVs ranged between 1.7 and 7.8, and the RFA values ranged between 30 and 46 with nonrelevant group differences. The 3-year survival rates were 92% in group A versus 95% in group B and 99% in the mandible (one failure) versus 87% in the maxilla (eleven failures among four participants).

Conclusions

Within the limitations of explorative analyses, there were no relevant differences between immediate and delayed loading regarding survival or stability of strategic MIs.

Clinical relevance

The stability values for MIs are lower than for conventional implants. The MI failure rate in the maxilla is higher than in the mandible with cluster failure participants.

Clinical trial registration

German Clinical Trials Register (Deutsches Register Klinischer Studien, DRKS-ID: DRKS00007589, www.germanctr.de), January 15, 2015.

Upgrading removable denture design by using strategic implants: A case report

Inserting a dental implant in a strategic position under a removable partial denture (RPD) can upgrade the RPD design by changing a mainly tissue-supported RPD to an implant-tissue-supported RPD or an implant-tooth-tissue-supported RPD with better retention, support, and stability. CASE PRESENTATION: The patient (female, 77-year-old) was unsatisfied with her maxillary and mandibular clasp-retained removable dentures (RDs). Medical, social, and systemic health evaluations revealed that the patient was healthy. Dental history, intraoral and extraoral examinations, functional screening, and esthetic analyses revealed that the patient had a reduced vertical dimension, resulting in pseudo-class III malocclusion and angular cheilitis. Strategic implants were used to improve the retention, support, and stability of the new RDs. The maxillary canine 23 (World Dental Federation notation) and maxillary premolar 24 were used to retain the maxillary conical crown attachments. Three strategic mini-implants were inserted in the positions of teeth 12, 13, and 14 to support and retain the maxillary RPD. Two locators above the standard implants (33 and 43) were used to support and retain the mandibular overdenture. An improvement in the oral health-related quality of life and patient satisfaction with respect to the maxillary and mandibular RDs was observed immediately after using the new RDs. This improvement did not diminish after a year. CONCLUSION: Herein, using strategic implants to support the maxillary RPD and two standard implants under the mandibular overdenture improved the oral health-related quality of life and patient satisfaction with respect to the maxillary and mandibular prostheses in terms of the retention, stability, support, eating ability, speaking ability, appearance, and cleanability.

Immediate versus delayed loading of strategic mini-implants under existing removable partial dentures: patient satisfaction in a multi-center randomized clinical trial

OBJECTIVE

The purpose of this study was to evaluate and compare the effects of the immediate and delayed loading of strategic mini-implants (MIs) on the satisfaction of patients with removable partial dentures (RPDs).

MATERIALS AND METHODS

In this multi-center randomized clinical trial, strategic MIs were inserted under 79 RPDs in 76 participants. Two questionnaires, one for the upper jaw and one for the lower jaw, were given before surgical intervention and 2 weeks, 4 months, 4.5 months, 1 year, 2 years, and 3 years after implant insertion. To estimate the loading effect (immediate vs. delayed) in terms of the odds ratio, an ordinal logistic regression model was used. The Wilcoxon matched-pairs signed-rank test, which was corrected for clusters in the patient population, was used to evaluate changes in patient satisfaction.

RESULTS

After 4 months, a statistically significant difference in favor of the immediate loading group was recognized in terms of the overall satisfaction score. The patient satisfaction scores recorded after 4.5 months and 1, 2, and 3 years showed substantial improvements compared with the scores recorded before implant insertion in both groups. At the item level, substantial improvements were noted in the following domains: general satisfaction, RPD retention, stability, support, eating, speaking, and aesthetics.

CONCLUSIONS

Strategic MIs improved the satisfaction of patients with RPDs during the medium-term follow-up period. An earlier improvement in the satisfaction of patients with RPDs was seen after immediate loading of the MIs as compared with delayed loading.

CLINICAL RELEVANCE

Inserting MIs under existing RPDs can improve patients' satisfaction with their RPDs in several domains.

Comparison of Three Prosthodontic Treatment Modalities for Patients with Periodontally Compromised Anterior Mandibular Teeth: A 2-year follow-up study

OBJECTIVES

To prospectively assess self-perceived chewing function (CF) and oral health-related quality of life (OHRQoL) in geriatric patients after receiving three different treatment modalities in the mandible: removable partial denture (CD-RPD), complete denture (CDs), or complete overdenture supported by mini dental implants (CD-MDI). At baseline, all patients had mobile anterior teeth (1 mm or >) and missing posterior teeth in the mandible. Patients were completely edentulous in the maxilla. After treatment, patients were recalled at the 3-month and the 2-year post-treatment period.

MATERIALS AND METHODS

A total of 176 patients participated (CD group, n=68; CD-RPD group, n=58; CD-MDI group, n=50). Self-reported CF was assessed using the Chewing Function questionnaire (CFQ), The OHRQoL was evaluated using the OHIP14 questionnaire, which the patients completed 1. before treatment, 2. three months after treatment, and 3. at the 2-year post-treatment stage.

RESULTS

The OHRQoL and the self-perceived CF significantly improved in all groups after treatment (p<0.01). The highest improvement of a CF was recorded in the CD-MDI group. The OHRQoL was significantly higher in the CD-MDI group in comparison to the CDs group after treatment (p<0.01). At the 2-year post-treatment stage, self-perceived CF significantly further improved in the CD-MDI group, while it worsened in the CD and the CD-RPD groups (p<0.01). The same pattern was recorded for the OHIP14 summary scores. The highest amount of denture repairs and adjustments was recorded in the CD-RPD group, although maintenance was also demanding in the CD-MDI group.

CONCLUSION

Within the limitations of this study, rehabilitation with mandibular MDI retained overdenture can be considered as preferred treatment with the constant improvement of OHRQoL and a chewing function in comparison to mandibular CD or mandibular RPD option in patients with mobile anterior mandibular teeth.

[Factors affecting osteointegration and the use of early functional load to reduce the duration of treatment in dental implantation]

The article presents literature data on the impact of the surface and shape of dental implants and early functional load with aesthetic and functional rehabilitation on osteointegration and stability of implants at various implantation terms.

Clinical outcome of removable prostheses supported by mini dental implants. A systematic review

INTRODUCTION

For many years, edentulous patients have had no other option than conventional dentures to reestablish their oral function. To avoid the need for bone graft surgery, some professionals have suggested the use of mini dental implants (MDIs) to support prostheses. The MDIs are narrow implants, ranging approximately from 1.8 to 2.9 mm in diameter. Recently, the promising results of mini implants regarding osseointegration and patient satisfaction have led clinicians to accept them as a definitive treatment option.

OBJECTIVE

Therefore, the proposition of this systematic review was to assess information on the outcomes of MDIs supporting removable prostheses.

METHODS

The PubMed and Cochrane databases were searched for articles published before September 2017, which yielded a total of 774 studies for analysis. After exclusion and inclusion criteria, 22 prospective studies were included in this systematic review.

RESULTS

Most mini implants were placed in a flapless single-stage surgery and loaded immediately. Most studies reported failures in the first year and prosthetic complications. The mean survival rate of the selected studies was 95.6%, and mean follow-up was 22.8 months.

CONCLUSION

The MDI-supported removable prostheses successfully improved patients' chewing and speaking ability, quality of life, and satisfaction, suggesting that MDIs are a viable and safe option to support removable prostheses in the mandibular arch.

Low serum vitamin D and early dental implant failure: Is there a connection? A retrospective clinical study on 1740 implants placed in 885 patients

Background. Since osseointegration depends on bone metabolism, low levels of vitamin D in the blood may negatively affect bone formation around dental implants. To date, only a few studies have investigated the possible connection between serum levels of vitamin D and early dental implant failure (EDIF), i.e. failure that occurs within 4 months after placement, before the connection of the prosthetic abutment. The aim of this study was to investigate whether there is a relationship between low serum levels of vitamin D and EDIF.

Methods. Data used for this retrospective study were derived from the records of a private dental clinic. Inclusion criteria were patients who had been treated with dental implants, inserted with a submerged technique from January 2003 to December 2017. EDIF was the outcome of this study. Chi-squared test was used to investigate the effect of patient-related variables (age, gender, smoking habit, history of periodontal disease and serum levels of vitamin D) on EDIF.

Results. Originally, 885 patients treated with 1,740 fixtures were enrolled in this study. Overall, 35 EDIFs (3.9%) were reported. No correlation was found between EDIF and the patients' gender (P=0.998), age (P=0.832), smoking habit (P=0.473) or history of periodontal disease (P=0.386). Three EDIFs (11.1%) were reported in 27 patients with serum levels of vitamin D <10 ng/mL, 20 EDIFs (4.4%) in 448 patients with levels between 10 and 30 ng/mL, and 12 EDIFs (2.9%) in 410 patients with levels >30 ng/mL. Although there was a clear trend toward an increased incidence of EDIF with lowering of serum vitamin D levels, no statistically significant difference (P=0.105) was found among these three groups.

Conclusion. Within its limitations (retrospective design, low number of patients with severe blood levels of vitamin D enrolled), this study failed to demonstrate a significant relationship between low serum levels of vitamin D and increased risk of EDIF. However, since a dramatic increase in EDIFs with lowering of vitamin D levels in the blood has been reported, further clinical studies with appropriate design (prospective or randomized controlled studies on a larger sample of severely deficient patients) are needed to better investigate this topic

Immediate loading implants: review of the critical aspects

Purpose

Modern dentistry have witnessed, a rapid and continuing evolution. Concerning the implant-rehabilitation protocols, they have been redefined in order to satisfy patient's increasing expectations in terms of comfort, aesthetic and shorter treatment period. The purpose of this review is to explore the concept of implant immediate loading and the indications for clinical practice. All the critical aspects that could influence the outcomes of this treatment will also be considered.

Materials and methods

Three protocols for implant load timing have been classified: immediate loading implants (ILI); early loading implants (ELI); and conventional loading implants (CLI). Two subclassifications point out the different loading modality: 1) Occlusal loading or Non-Occlusal loading, 2) Direct loading or Progressive loading. Micromovements have been considered, since the start of implant dentistry, one of the main risk for the success of osseointegration. The determinant and most accessible parameter to assess the primary stability is the implant insertion torque value. To achieve the necessary torque value to perform immediate loading, it is therefore important to evaluate the bone density at the implant site. Computerized tomography (CT) has been regarded as the best radiographic method to evaluate the residual bone.

Results

The clinical success of this technique is highly dependent on many factors: patient selection, bone quality and quantity, implant number and design, implant primary stability, occlusal loading and clinician's surgical ability. Among these, implant primary stability is undoubtedly the most important.

Conclusion

Studies on ILI show that successful outcome can be expected, if the previous criteria are fulfilled. It seems that ILI demonstrate a greater risk for implant failure when compared to CLI, although the survival rates were high for both the procedures. The use of different surgical procedures, type of prostheses, loading times and have very different study designs. This lack of homogeneity limits the relevance of the conclusions that can be drawn.