SCIENTIFIC HIGHLIGHTS
Short overviews on recently published scientific evidence.
Issue 5/2024
Edited by Dr. Marcin Maj
IN THIS ISSUE
EDITOR’S CHOICE
Reverse scan body: Complete digital workflow for double full-arch zirconia prostheses
(Panos Papaspyridakos et al. 2024) and
Mandibular overdentures retained by 1 or 2 implants: a 5-year randomized clinical trial on implant stability and peri-implant outcomes
(Cláudio Rodrigues Leles et al., 2024)
The flapless approach with and without enamel matrix derivatives for the treatment of intrabony defects: A randomized controlled clinical trial
(Mario Aimetti et al., 2024)
EDITOR’S CHOICE
J Prosthodont. 2024 Aug 7
Reverse scan body: Complete digital workflow for double full-arch zirconia prostheses
Panos Papaspyridakos, Lina Castellanos, E Armand Bedrossian, Davide Romeo, Yukio Kudara, Konstantinos Chochlidakis
ABSTRACT
During intraoral complete-arch digital implant scanning, one of the most technique-sensitive steps is the implant data acquisition and merging of different surface geometry data sets for prototype prosthesis fabrication due to the absence of fixed landmarks. Recently developed extraoral techniques have allowed for an alternative approach for the digital acquisition of implant position in completely edentulous patients. Specifically, extraoral digital scanning of the conversion prosthesis after connecting reverse scan bodies has been proposed as an efficient approach. The reverse scan body protocol digitally simulates the traditional back-pouring technique long utilized in analog workflows. The present article describes a technique for simplifying the digital workflow for the fabrication of passive-fitting definitive prostheses using the reverse scan body concept.
Adapted from P Papaspyridakos et al., J Prosthodont. 2024 Aug 7, for more info about this publication click HERE
Clin Oral Investig. 2024 Sep 16;28(10):527
Mandibular overdentures retained by 1 or 2 implants: a 5-year randomized clinical trial on implant stability and peri-implant outcomes
Cláudio Rodrigues Leles, Gabriela Pereira de Resende, Nilva de Oliveira Martins, Lays Noleto Nascimento, Nadia Lago Costa, Murali Srinivasan, Martin Schimmel
STUDY OBJECTIVES AND METHODS
The purpose of this study was to compare longitudinal implant stability, and clinical and radiographic peri-implant outcomes of mandibular overdentures retained by one (1-IOD group) or two (2-IOD group) implants. All participants received 4.1 mm diameter tissue-level implants (Straumann® Standard Plus - SLActive®, Institut Straumann AG), installed in the mandible midline (1-IOD; n = 23) or the lateral incisor-canine area bilaterally (2-IOD; n = 24), and loaded after 3 weeks. Implant Stability Quotient (ISQ) was measured using a resonance frequency device (Osstell® Mentor, Integration Diagnostics) at implant placement, after three weeks (loading), and at the 6-month, 1-, 3-, and 5-year follow-ups. Marginal bone loss and clinical implant outcomes (plaque, calculus, suppuration and bleeding) were assessed periodically up to 5 years after loading.
RESULTS
• Only minor changes in marginal bone level were observed after 5 years (mean = 0.37; SD = 0.44 mm), and satisfactory and stable peri-implant parameters were observed throughout the 5-year follow-up.
• No significant differences between groups were found. Overall, the mean primary implant stability was considered high (> 70) for the two groups (1-IOD = 78.1 ± 4.5; 2-IOD = 78.0 ± 5.8).
• No noticeable changes were observed between implant insertion and loading. A marked increase was observed from insertion to the 6-month follow-up - the mean difference for the 1-IOD group was + 5.5 ± 5.5 (Effect size = 1.00), while for the 2-IOD group, the mean difference was + 6.0 ± 5.6 (Effect size = 1.08).
• No relevant changes were observed throughout the follow-up periods up to 5 years.
• Linear mixed-effect model regression showed no influence of the bone-related variables (p > 0.05) and the number of implants (p = 0.087), and a significant effect of the time variable (p < 0.001).
CONCLUSIONS
Satisfactory peri-implant outcomes and stable secondary stability suggest good clinical performance and successful long-term osseointegration of the implants for single and two-implant mandibular overdentures. Using a single implant to retain a mandibular overdenture does not seem to result in detrimental implant loading over the five years of overdenture use.
Adapted from CR Leles et al., Clin Oral Investig. 2024 Sep 16;28(10):527, for more info about this publication click HERE
J Clin Periodontol. 2024 Sep;51(9):1112-1121
The flapless approach with and without enamel matrix derivatives for the treatment of intrabony defects: A randomized controlled clinical trial
Mario Aimetti, Morta Stasikelyte, Giulia Maria Mariani, Luca Cricenti, Giacomo Baima, Federica Romano
STUDY OBJECTIVES AND METHODS
The aim of this study was to compare the clinical and radiographic outcomes of flapless procedure alone or in combination with enamel matrix derivatives (EMD) in the treatment of deep intrabony defects. Forty-six patients re-evaluated after non-surgical therapy were randomly assigned to the test (flapless with EMD) or control group (flapless alone). Clinical measurements were recorded pre-surgery and at 6 and 12 months after surgery, and radiographic measurements were taken pre-surgery and after 12 months.
RESULTS
• Forty-six patients completed the study.
• Improvements were observed in both groups at 12 months for mean clinical attachment level (CAL) gain, with significant differences between test (3.9 ± 1.1 mm) and control groups (3.0 ± 1.2) (p = .017). Probing pocket depth (PPD) reduction (4.0 ± 0.7 vs. 3.3 ± 1.4 mm) was also near to statistical significance (p = .051).
• Also, more sites achieved successful composite outcome measure (final PPD ≤ 4 mm and CAL gain ≥3 mm) for the regenerative treatment in the flapless + EMD group (82.6% vs. 52.2%; p = .028).
• In terms of radiographic outcomes, EMD yielded a greater defect bone fill than flapless treatment alone (3.0 ± 1.0 mm vs. 1.8 ± 1.5 mm; p < .001)
CONCLUSIONS
The additional application of EMD during the flapless procedure for intrabony defects slightly improved clinical and radiographic outcomes.
Adapted from M Aimetti et al., J Clin Periodontol. 2024 Sep;51(9):1112-1121, for more info about this publication, click HERE
BMC Oral Health. 2024 Aug 6;24(1):902
Influence of titanium and titanium-zirconium alloy as implant materials on implant stability of maxillary implant retained overdenture: a randomized clinical trial
Amany Ibrahim Abd El-Hady, Hany Ibrahim Eid, Shaimaa Lotfy Mohamed, Sawsan Maged Fadl
STUDY OBJECTIVES AND METHODS
The aim of this study was to compare between two implant materials (roxolid and traditional titanium) on the primary and secondary stability of implant retained maxillary overdenture. Eighteen completely edentulous patients were selected. All patients received maxillary implant-retained overdentures and lower complete dentures; patients were divided equally into two groups according to the type of implant materials. Group A received a total number of 36 implants made of roxolid material and Group B received a total number of 36 implants made of traditional titanium alloys. Implant stability was assessed using ostell device, the primary implant stability was measured at the day of implant installation however, secondary implant stability was measured after six weeks of implant placement. Paired t-test was used to compare between primary and secondary stability in the same group and an independent t-test was used to compare between the two groups with a significant level < 0.05.
RESULTS
• Independent t-test revealed a significant difference between the two groups with p -value = 0.0141 regarding primary stability and p-value < 0.001 regarding secondary stability, as roxolid implant group was statistically higher stability than titanium group in both.
• Paired t- test showed a statistically significant difference in roxolid implant group with p-value = 0.0122 however, there was non-statistically significant difference in titanium group with p-value = 0.636.
• Mann Whitney test showed a significant difference between the two groups regarding amount of change in stability with p value = 0.191. roxolid implant group showed a higher amount of change in stability than the titanium implant group.
CONCLUSIONS
Within the limitation of this study, it could be concluded that: Roxolid implants showed promising results regarding primary and secondary stability compared to conventional Titanium implants and can be a better alternative in implant retained maxillary overdentures.
Adapted from AIA El Hady et al., Randomized Controlled Trial BMC Oral Health. 2024 Aug 6;24(1):902, for more info about this publication, click HERE
Clin Oral Implants Res. 2024 Aug 3
Fracture rate and risk factors associated with the fracture of narrow diameter implants: A long-term retrospective analysis
Romulo M Lustosa, João Garcez-Filho , Marcos Seabra , Ricardo Puziol de Oliveira , Flávia Matarazzo , Maurício G Araújo
STUDY OBJECTIVES AND METHODS
The purpose of this study was to evaluate the fracture rate and the risk factors associated with the fracture of 3.3 mm narrow diameter implants (NDIs) A total of 524 records of patients rehabilitated with 3.3 mm NDIs between 1997 and 2015 were assessed. Data on patients, implants, and prostheses were collected, and descriptive analysis of the variables was performed. NDIs were separated into 2 groups: "fractured" and "non-fractured", and a multilevel logistic regression model was applied to identify the risk factors associated with NDI fracture.
RESULTS
• Eighty-four patients were removed from the analysis for interrupting follow-up or presenting failures other than fractures.
• Of the 440 patients included (64.66 ± 13.4 years), 272 were females (61.8%), and 168 males (38.2%), and mean followup time was 129 ± 47.1 months.
• Of the 1428 NDIs, 15 (1.05%) in 9 patients (2.04%) fractured during the studied period. Ten fractures (66.66%) happened in 6 patients (66.66%) showing signs of parafunction.
• NDI with modified sandblasted, large grit, acid-etched surface was the only implant variable to show a protective statistical significance (p = .0439).
CONCLUSIONS
NDI fracture was a rare event in the studied sample. NDIs manufactured with modified sandblasted, large grit, acid-etched surface may provide extra protection against NDI fracture. Patient-specific factors and implant characteristics should be carefully considered to limit the risk of fracture of 3.3 mm NDIs.
Adapted from RM Lustosa et al., Clin Oral Implants Res. 2024 Aug 3, for more info about this publication, click HERE
Clin Implant Dent Relat Res. 2024 Sep 26
Does alveolar ridge preservation reduce the need for sinus floor elevation: A comparative study to spontaneous healing
Elias Jean-Jacques Khoury, Keyvan Sagheb, Bilal Al-Nawas, Jochem König, Eik Schiegnitz
STUDY OBJECTIVES AND METHODS
The aim of this study was to explore if alveolar ridge preservation, using a bovine bone substitute and a porcine collagen membrane, significantly decreases the need for sinus lifts compared to natural wound healing after tooth extraction. In this comparative clinical study, 40 patients requiring a total of 53 extractions were assigned to one of the following groups: a test group with bovine bone substitute material (Straumann® XenoFlex) and a porcine collagen membrane (Jason® membrane), or a control group with spontaneous socket healing. After 6 months, digital volume tomography was performed for implant planning.
RESULTS
• For seven patients from the control group (n = 22 extracted sites) sinus lift augmentations were performed while only four sinus lift procedures were performed in the test group (n = 31 extracted sites), indicating a higher need for sinus augmentation procedures in the control group, however not statistically different on a p value of 0.05 (p = 0.168).
• In the control group, the mean value of the radiographically measured bone height (mesial and distal) was 11.13 ± 2.12 mm preoperatively before tooth extraction, while it was 11.3 ± 2.17 mm postoperatively after implant placement.
• In contrast, the mean value in the test group was 11.78 ± 3.09 mm preoperatively and 11.92 ± 2.79 mm postoperatively. Statistical analysis revealed no significant difference between the two groups (odds ratio 0.32; 95% CI: 0.08, 1.26; p = 0.951).
• The implant survival rate in the control group was 100%, compared to 96.77% in the test group.
CONCLUSIONS
Within the limits of this study, the use of bovine bone substitute and a porcine resorbable membrane after tooth extraction in the posterior maxilla seems to reduce the need for sinus augmentation in comparison to spontaneous healing although the difference was not statistically significant. Additionally, the Alveolar Ridge Preservation in the test group made external sinus floor elevation unnecessary compared to the control group. The change in radiographically measured bone height pre- and postoperatively showed no significant difference between the two groups.
Adapted from EJJ Khoury et al., Clin Implant Dent Relat Res. 2024 Sep 26 , for more info about this publication, click HERE
JBMR Plus. 2024 Aug 31;8(10):ziae113
Healing sequelae following tooth extraction and dental implant placement in an aged, ovariectomy model
Jessica M Latimer, Shogo Maekawa, Takahiko Shiba, Tobias Fretwurst, Michael Chen, Lena Larsson, James V Sugai, Paul Kostenuik , Bruce Mitlak, Beate Lanske, William V Giannobile
STUDY OBJECTIVES AND METHODS
The aim of this study was to to investigate the outcomes of dental tooth extraction socket healing and implant placement in a rodent model of osteoporosis following daily vehicle (VEH) or abaloparatide (ABL) administration.
RESULTS
• Micro-CT and histologic analysis demonstrated signs of delayed wound healing, consistent with alveolar osteitis in extraction sockets following 42 d of healing in both the VEH and ABL groups.
• In a semiquantitative histological analysis, the OVX-ABL group demonstrated a tendency for improved socket regeneration with a 3-fold greater rate for moderate socket healing when compared to the OVX-VEH group (43% vs 14%), however, this finding was not statistically significant (p=.11).
• No significant differences were observed between vehicle and test groups in terms of implant outcomes (BMD and bone volume/total volume) at 14- and 21-d post-implant placement.
• Abaloparatide (ABL) significantly increased BMD of the femoral shaft and intact maxillary alveolar bone sites in OVX animals, demonstrating the therapeutic potential for oral hard tissue regeneration.
CONCLUSIONS
The present model involving estrogen-deficiency-induced bone loss demonstrated an impaired healing response to dental extraction and implant installation.
Adapted from JM Latimer et al., JBMR Plus. 2024 Aug 31;8(10):ziae113, for more info about this publication, click HERE
REFERENCES
P Papaspyridakos et al., J Prosthodont. 2024 Aug 7 | CR Leles et al., Clin Oral Investig. 2024 Sep 16;28(10):527 | M Aimetti et al., J Clin Periodontol. 2024 Sep;51(9):1112-1121 | AIA El Hady et al., BMC Oral Health. 2024 Aug 6;24(1):902 | RM Lustosa et al., Clin Oral Implants Res. 2024 Aug 3 | EJJ Khoury et al., Clin Implant Dent Relat Res. 2024 Sep 26 | JM Latimer et al., JBMR Plus. 2024 Aug 31;8(10):ziae113 | source: www.pubmed.gov | Dr. Marcin Maj holds the position of Head of Global Scientific Affairs at Institute Straumann in Basel, Switzerland
