Nicole Passia

The Randomized Shortened Dental Arch Study 5-year Maintenance

The scientific evidence concerning prosthodontic care for the shortened dental arch (SDA) is sparse. This randomized multicenter study aimed to compare two common treatment options: removable partial dental prostheses (RPDPs) for molar replacement vs. no replacement (SDA). One of the hypotheses was that the follow-up treatment differs between patients with RPDPs and patients with SDAs during the 5-year follow-up period. Two hundred and fifteen patients with complete molar loss in one jaw were included in the study. Molars were either replaced by RPDPs or not replaced according to the SDA concept. A mean number of 4.2 (RPDP) and 2.8 (SDA) treatments for biological or technical reasons occurred during the 5-year observation time per patient. Concerning the biological aspect, no significant differences between the groups could be shown, whereas treatment arising from technical reasons was significantly more frequent for the RPDP group. When the severity of treatment was analyzed, a change over time was evident. When, at baseline, only follow-up treatment with minimal effort is required, over time there is a continuous increase to moderate and extensive effort observed for both groups (Controlled-trials.com number ISRCTN97265367).

Ten-year clinical outcome of three-unit posterior FDPs made from a glass-infiltrated zirconia reinforced alumina ceramic (In-Ceram Zirconia).

OBJECTIVES To evaluate the long-term survival and complication rates of posterior three-unit fixed dental prostheses (FDPs) fabricated from a glass-infiltrated zirconia reinforced alumina ceramic (In-Ceram Zirconia). METHODS Fifty-eight patients received 65 FDPs. Twelve FDPs replaced the second premolar (8 in the maxilla, 4 in the mandible), and 53 replaced the first molar (19 in the maxilla, 34 in the mandible). The In-Ceram Zirconia ceramic frameworks were designed and milled using the Cerec CAD/CAM system. The minimum dimension of the proximal connectors of the frameworks was 12 mm(2) and 16 mm(2) for premolars and molars, respectively. After milling and glass infiltration, the frameworks were veneered with a feldspathic ceramic. All FDPs were cemented with glass-ionomer cement. The patients were recalled 6-12 months after placement, and then annually. Kaplan-Meier analysis was used to calculate the survival and complication rates of the FDPs. RESULTS The mean observation time was 9.7 years. Six patients with 6 FDPs were regarded as dropouts. Using the Kaplan-Meier method the 10-year cumulative survival rate was 93.6%. In a worst-case scenario, in which the 6 missing FDPs are considered as failed, the 10-year survival rate would be 84.6%. CONCLUSION Three-unit posterior FDPs made from In-Ceram Zirconia presented a 10-year survival rate similar to that reported for conventional FDPs. However more technical and biological complications were reported. CLINICAL SIGNIFICANCE Three-unit posterior FDP made from In-Ceram Zirconia may be a viable treatment modality, taking the strict adherence to the manufacturers recommendations into consideration.

Long-term retention behaviour of resin matrix attachment systems for overdentures.

OBJECTIVES The purpose of this laboratory study was to evaluate the long-term retention behaviour of two resin matrix attachment systems for overdentures and the influence of the implant angulation. METHODS Sixteen titanium patrices of each attachment system were connected to their corresponding implant analogues and fixed in an auto curing resin either orthogonally (n=8) or 20° tilted (n=8). The corresponding matrices, one made from polyetherketoneketone (PEKK; CM LOC, Cendres+Métaux, Biel, Switzerland), one made from polyethylene (PE; Locator, Zest Anchors, Escondido, California, USA), were fixed in a stylised unilaterally removable dental prosthesis resulting in 4 groups with 8 specimens in each group. Overall, 30,000 joining and separating cycles of the matrix were performed in a chewing simulator. After each joining movement, the unilaterally removable dental prosthesis was loaded eccentrically with 100N at a distance of 12mm from the attachment to simulate clinical loading conditions. Retentive forces were measured during the test using force transducers. The statistical analysis was performed using Tukey-HSD. RESULTS Both attachment systems showed a significant decrease in retention over time, which occurred earlier in the tilted groups than in the orthogonal groups. After 5000-30,000 joining and separating cycles the PE matrix attachment provided significantly lower retention than the PEKK matrix attachment system. CONCLUSION Within the limitations of this investigation, the combination of a titanium patrix and a matrix made from polyetherketoneketone seems to be a promising material combination for long-term retention, also on tilted implants.

Ten-year outcome of zirconia ceramic cantilever resin-bonded fixed dental prostheses and the influence of the reasons for missing incisors

OBJECTIVES This clinical study evaluated the long-term outcome and survival rate of all-ceramic cantilever resin-bonded fixed dental prostheses (RBFDPs) made of zirconia-ceramic with a single-retainer design to replace missing incisors. In addition, whether the reason for missing incisors has an influence on the longevity of RBFDPs was analyzed. MATERIALS AND METHODS One hundred and eight zirconia ceramic cantilever RBFDPs were provided for 87 patients. Seventy-five RBFDPs replaced maxillary incisors and 33 mandibular incisors. The restorations were subsequently categorized into 3 groups according to the reasons for missing teeth (congenitally missing, trauma and other reasons). The patients were followed up annually, and the restorations were assessed for function and aesthetics. The mean observation time of the RBFDPs was 92.2±33months. RESULTS Six debondings and 1 loss of restoration were recorded. The lost restoration was removed at the patients request after a small chip occurred on the mesial edge of the pontic. Three of the 6 observed debondings were caused by traumatic incidents. All debonded RBFDPs were rebonded successfully with no further complications. Zirconia ceramic RBFDPs yielded a 10-year survival rate of 98.2% and a success rate of 92.0%. CONCLUSIONS Anterior zirconia ceramic cantilever RBFDPs provided excellent clinical longevity. The reasons for missing incisors did not influence the longevity of the cantilever RBFDPs.

All-ceramic inlay-retained fixed dental prostheses: An update

Inlay-retained fixed dental prostheses (IRFDPs) represent a minimally invasive alternative to conventional fixed dental prostheses (FDPs) to replace single posterior missing teeth. The aim of the present review article is to assess the clinical outcome of different IRFDPs in order to derive recommendations regarding their clinical application. Hence, it is essential to highlight important factors that influence the longevity and success of IRFDPs, such as treatment plan, appropriate case selection with proper indications, as well as tooth preparation. Furthermore, a good understanding of bonding technologies and awareness of pretreatment procedures for different materials are indispensable for the long-term success of IRFDPs.

Single Mandibular Implant Study: Recruitment Considerations.

PURPOSE The aim of this multicenter single mandibular implant study was to compare the clinical outcome of an immediately loaded implant placed in the midline of an edentulous mandible with the clinical outcome when closed healing and delayed loading is chosen. Here, the patient recruitment period and the main reasons for exclusion were analyzed. MATERIALS AND METHODS Patient recruitment was performed at nine German universities. Rather conservative inclusion and exclusion criteria, including denture satisfaction, denture status, a psychologic symptom checklist, and a defined bone height in the posterior mandible, had to be fulfilled. It was initially calculated that 230 persons would have to be screened within 13 months to include 180 persons in the trial. RESULTS Within 13 months (December 2012 to December 2013), 201 patients were screened for possible inclusion in the trial and 148 met the inclusion criteria. Finally, after the recruitment period was extended by 2.5 months, 224 patients were screened and 169 were included. Of those screened, 55 (24.6%) did not meet the inclusion criteria and were excluded. Another 4 patients (1.8%) were excluded based on their psychologic symptom checklist score, while 5 others (2.8%) showed signs of noncompliance. A further 8 patients (4.4%) decided not to participate and withdrew their informed consent, and another 3 (1.3%) were no longer available after screening. Another 2 patients were excluded due to medical contraindications and 1 due to an insufficient mandibular denture. In 34 cases (15.2%), the residual bone height did not comply with McGarry type II or III. CONCLUSION Within the limitations of this patient recruitment period, it can be concluded that residual bone height is the most important factor when considering elderly edentulous patients for implant therapy. The psychologic symptom checklist score was less important.

Bond strength of a new generation of universal bonding systems to zirconia ceramic

The purpose of this laboratory study was to evaluate the tensile bond strength of a new generation of universal bonding systems to zirconia ceramic and to compare the results with the bond strength of a clinically-established bonding system. Eighty zirconia ceramic test specimens (e.max ZirCAD) were air-abraded and bonded to Plexiglas tubes, filled with an aliphatic dimethacrylate filling material (Clearfil F II), using three so called universal bonding systems of a new generation with different compositions (Monobond Plus/MultilinkAutomix, NX3, Scotchbond Universal/RelyX Ultimate). The latter was used also without the phosphate monomer containing primer Scotchbond Universal. A clinically established phosphate monomer containing adhesive cement served as control group (Panavia F2.0). The specimens were stored in water at 37°C for 3 or 150 days and the long-term storage series were additionally thermal cycled between 5 and 55°C for 37,500 times to simulate oral conditions. All specimens underwent tensile bond strength testing. The statistical analysis was performed using Kruskal-Wallis and Wilcoxon-Test with a Bonferroni-Holm correction for multiple testing. After 150 days the median bond strength of RelyX Ultimate, with and without Scotchbond Universal, and Panavia F2.0 did not differ statistically (range: 21.7-28.8MPa), while the bond strength of Monobond Plus/Multilink Automix was significantly lower (15.4MPa), and that of NX3 the lowest (6.6MPa). After 150 days of water storage with thermal cycling, all adhesive system showed significantly reduced tensile bond strengths compared to that after 3 days. Only RelyX Ultimate was comparable to the established bonding system Panavia F2.0. The additional use of Scotchbond Universal did not result in a significant effect.

Survival and Complications of Single Dental Implants in the Edentulous Mandible Following Immediate or Delayed Loading: A Randomized Controlled Clinical Trial:

It was the aim of this 24-mo randomized controlled clinical trial to investigate whether the survival of a single median implant placed in the edentulous mandible to retain a complete denture is not compromised by immediate loading. Secondary outcomes were differences in prosthetic complications between the loading principles. Each of the 158 patients who received an implant was randomly assigned to the immediate loading group (n = 81) or the delayed loading group (n = 77). Recall visits were performed 1 mo after implant placement (for only the delayed loading group) and 1, 4, 12, and 24 mo after implant loading. Nine implants failed in the immediate loading group, all within the first 3 mo of implant loading, and 1 implant failed in the delayed loading group prior to loading. Noninferiority of implant survival of the immediate loading group, as compared with the delayed loading group, could not be shown (P = 0.81). Consistent with this result, a secondary analysis with Fisher exact test revealed that the observed difference in implant survival between the treatment groups was indeed statistically significant (P = 0.019). The most frequent prosthetic complications and maintenance interventions in the mandible were retention adjustments, denture fractures, pressure sores, and matrix exchanges. There was only 1 statistically significant difference between the groups regarding the parameter “fracture of the denture base in the ball attachment area” (P = 0.007). The results indicate that immediate loading of a single implant in the edentulous mandible reveals inferior survival than that of delayed loading and therefore should be considered only in exceptional cases (German Clinical Trials Register: DRKS00003730).

The single mandibular implant study – Short-term effects of the loading protocol on Oral Health-related Quality of Life

PURPOSE A single implant can be placed to retain an overdenture in the edentulous mandible. This study aimed at the development of Oral Health-related Quality of Life comparing immediate and delayed implant loading, i.e., loading after 3 months of submerged healing. METHODS In a randomized controlled trial, 158 participants received a single mandibular implant in the midline. Quality of life was measured using the summary score of the German 49-item Oral Health Impact Profile at baseline, one month after implant placement (direct loading group) as well as one and four months after loading. RESULTS Mean scores at baseline were comparable. Four months after implantation, a decrease of mean scores was recognized for both groups, indicating a significantly enhanced quality of life after treatment. When comparing the groups after both 1 and 4 months of loading, quality of life was insignificantly higher in the delayed loading group (1 month: 42.1 vs. 32.3; 4 months: 33.6 vs. 27.7). For immediate loading, an insignificant tendency to an earlier improvement was recognized (Δ1month-baseline: 9.7, compared to Δ1month-baseline: 6.4). CONCLUSIONS The single mandibular implant concept was associated with a positive impact on quality of life. However, no statistically significant influence of implant loading on quality of life was found.

Single mandibular implant study (SMIS) − masticatory performance − results from a randomized clinical trial using two different loading protocols

OBJECTIVES This multi-centre randomized controlled trial was conducted to investigate, whether the masticatory performance of elderly edentulous patients is improved by placement of a single implant in the midline of the edentulous mandible, and whether improvements differ with respect to the loading protocol, i.e., implant is loaded either directly or three months later after second stage surgery. METHODS Edentulous seniors aged 60-89 years were screened according to inclusion and exclusion criteria and 163 underwent implant placement. Of those, 158 were randomly assigned either to the direct loading group A (n=81) or the conventional loading group B (n=77). Chewing efficacy was obtained before treatment, one month after implant placement during the submerged healing phase (only group B) and 1 and 4 months after implant loading. RESULTS The masticatory performance increased over time in both groups. Four months after loading, a significant increase was observed for both groups compared to the baseline data without implant (p≤0.05). However, between the two groups, chewing efficiency did not differ significantly at any point in time (p>0.05). CONCLUSIONS A single midline implant in the edentulous mandible increases masticatory performance significantly, independently from the loading protocol. CLINICAL SIGNIFICANCE A single midline implant in the edentulous mandible increases masticatory performance. The loading protocol has no influence.