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Highlights
Proceedings of RSU International Research Conference (2022)
P Pataraprasit, A Pimkhaokham
Study objectives and methods
Primary stability is an important factor to determine an osseointegration process. The Resonance Frequency Analysis (RFA) is approved to use for evaluating the implant stability due to the non-invasive and highly precise method. RFA values are converted to ISQ (Implant Stability Quotient) values ranging from 0 to 100. The newly launched aggressive thread design implant (BLX, Straumann, institute AG, Switzerland) was developed to maximize the stability of the implant. This pilot prospective cohort study was performed to investigate the stability of aggressive thread design implant (BLX) using Implant Stability Quotient (ISQ) values.
Patients who fulfilled the study requirements were selected. Twelve BLX implants were placed in the healed site without the need for guided bone regeneration under the manufacturer’s protocol. The RFA values were measured immediately after implantation and 6 weeks after implant placement at the buccal and mesial directions. The ISQ at the buccal and mesial sides were calculated for a mean ISQ in each follow-up time.
Results
• The mean ISQ value immediately after implant placement was 77.96 ± 5.81, ranging from 65.5 to 84.5. • The mean ISQ value at week 6 was 73.92 ± 4.38, ranging from 68.5 to 82. • The ISQ values at the buccal and mesial sides at the operative day as well as 6-week follow-up were not statistically significant (p = 0.709, 0.761). • The mean ISQ values on operation day and week 6 are also not significantly different (p = 0.177). • Regarding different insertion torque groups, for the implant that has the insertion torque over 50 Ncm, the mean
ISQ at the operative day is statistically significantly superior to the insertion torque group of 25-30 Ncm (p = 0.49).
Conclusions
In conclusion, the mean ISQ values of newly launch BLX implants were high and more than 70 indicating the high stability of this implant leading to successful clinical outcomes.
Adapted from P Pataraprasit et al., Proceedings of RSU International Research Conference (2022), for more info about this publication click HERE
Int J Oral Maxillofac Implants. 2022 May-Jun;37(3):525-532. doi: 10.11607/jomi.9367
Influence of Implant Diameter and Taper on Virtual Implant Placement in the Maxillary Central Incisor Position: A CBCT Analysis
A Hamilton, K Vazouras, B Friedland, G O Gallucci, A De Souza
Study objectives and methods
This study aimed to assess the influence of implant diameter and taper on the proximity of virtually planned maxillary central incisor implants to the nasopalatine canal and adjacent anatomical structures. Virtual implant planning was performed in the maxillary central incisor position. The distance between the implant and the incisive canal (IC) and the thickness of the surrounding buccal and palatal bone walls were measured. Implants were categorized as having an exposed implant surface, thin bone, or moderate/thick bone. Measurements were repeated for regular-/narrow-diameter and parallel/tapered implants.
Results
• A total of 60 patients were included, and 240 implants (60 of each type: 3.3-bone level [BL], 3.3-bone level tapered [BLT], 4.1-BL, and 4.1-BLT) were planned. • The percentages of implants with between 0 and 0.5 mm of remaining bone in the coronal aspect of the IC were 31.6% for 4.1-BL/BLT and 6.6% for 3.3-BL/BLT (P < .001). • The percentage of implants with IC exposure was 13.3% for 4.1-BL/BLT and 6.6% for 3.3-BL/BLT (P < .001). • The frequency of sites that required bone augmentation at the coronal facial aspect (< 1 mm) was 52.6% and 33.9% for 4.1-BL/BLT and 3.3-BL/BLT, respectively. • At the apical portion, the percentages of sites requiring bone augmentation at the facial aspect were 59.9%, 49.9%, 31.6%, and 23.3% for 4.1-BL, 3.3-BL, 4.1-BLT, and 3.3-BLT, respectively (P < .001).
Conclusions
The proximity of the nasopalatine canal is often < 0.5 mm from regular-diameter virtually planned implants at the most coronal aspect in the maxillary central incisor position. In these situations, the selection of narrow diameter implants significantly lowers the incidence of implant exposure and the need for additional management of the nasopalatine canal and also results in greater residual buccal and lingual bone thicknesses surrounding the implant. As expected, tapered implants reduced the risk of implant exposure through the buccal cortex at the apical aspect.
Adapted from A Hamilton.et al., Int J Oral Maxillofac Implants.2022 May-Jun;37(3):525-532, for more info about this publication click HERE
Acta Stomatol Croat . 2022 Jun;56(2):143-153. doi: 10.15644/asc56/2/5.
Short versus Standard Length Implants with Sinus Floor Elevation for the Atrophic Posterior Maxilla
E Schiegnitz, N Hill, K Sagheb, J König, K Sagheb, B Al-Nawas
Study objectives and methods
The aim of this clinical study was to compare clinical and radiological outcomes of short dental implants inserted in pristine bone to standard length implants inserted in combination with sinus floor elevation. For this clinical study, the clinical and radiological outcome of 126 short dental implants (84 patients), inserted in pristine bone were compared with 312 standard length implants (156 patients), placed in combination with maxillary sinus floor elevation procedures.
Results
• The short implant group (test group [TG]; mean follow-up (± standard deviation (SD) 56.6 ± 42.9 months) and the augmented group (control group [CG]; mean follow-up 41.6 ± 37.6 months) showed cumulative survival rates of 91.8% and 92.4%. • Cumulative 5-year implant survival rates were 91.8% for the TG and 90.7% for the CG (p=0.421). • Mean marginal bone loss was significantly higher in the CG than in the TG, with a mean MBL of 0.70 ± 0.72 mm in the TG and 0.96 ± 0.91 mm in the CG (p<0.001). • A comparable and promising oral health-related quality of life (OHRQoL) was observed in the control and test groups.
Conclusions
After over 3 years, short implants placed in the resorbed posterior maxilla obtained similar results to standard implants combined with maxillary sinus floor augmentation procedures.
Adapted from E Schiegnitz.et al., Acta Stomatol Croat . 2022 Jun;56(2):143-153, for more info about this publication click HERE
Clin Oral Implants Res. 2022 Jul;33(7):745-756. doi: 10.1111/clr.13954
Restorative angle of zirconia restorations cemented on non-original titanium bases influences the initial marginal bone loss: 5-year results of a prospective cohort study
F J Strauss, M Siegenthaler, C H F Hämmerle, I Sailer, R E Jung, D S Thoma
Study objectives and methods
To assess radiographic, restorative, clinical and technical outcomes as well as patient satisfaction of directly veneered zirconia restorations cemented on non-original titanium bases over 5 years.
Twenty-four patients with a single missing tooth in the aesthetic zone were recruited. All patients received a two-piece implant with a screw-retained veneered zirconia restoration cemented extraorally on a titanium base abutment. Marginal bone levels (MBL), marginal bone changes, technical complications, patient satisfaction and clinical parameters including probing depth, bleeding on probing and plaque index were assessed at crown delivery (baseline), at 1 year (FU-1) and 5 years (FU-5) of followup. To investigate the relationship between restorative angle and MBL as well as marginal bone changes (bone loss/bone gain), correlation tests and linear regression models were carried out.
Results
• Twenty-two patients were available for re-examination at 5 years. • The mean MBL amounted to 0.54 ± 0.39 mm at baseline, and to 0.24 ± 0.35 at FU-5 (=bone gain) (p < .001). At FU1, a positive correlation (r = .5) between the mesial restorative angle and mesial MBL was found (p = .012). • Marginal bone changes between baseline and FU-1 at mesial sites were also positively correlated with the mesial restorative angle (r = .5; p = .037). • Linear and logistic regression models confirmed that mesial marginal bone loss was significantly associated with the mesial restorative angle at FU-1 (p < .05). At 5 years, these significant associations at mesial sites disappeared (p > .05). • At distal sites, no correlations or associations between the restorative angle and MBL or marginal bone changes were found regardless of the time point. • During the 5-year follow-up, 5 technical complications occurred, mainly within the first year and mostly chippings. • All patients were entirely satisfied with their implant-supported restoration at 5 years.
Conclusions
Within the limitations of the present study, the restorative angle of implant-supported crowns on non-original titanium bases might influence the initial marginal bone loss but without affecting their favourable long-term clinical performance. A restorative angle of <40° may limit the initial marginal bone loss at implant-supported crowns with titanium bases.
Adapted from F J Strauss et al., J Clin Oral Implants Res. 2022 Jul;33(7):745-756., for more info about this publication click HERE
Clin Oral Investig. 2022 May 20. doi: 10.1007/s00784-022-04494-x
Comparative analysis of lateral maxillary sinus augmentation with a xenogeneic bone substitute material in combination with piezosurgical preparation and bony wall repositioning or rotary instrumentation and membrane coverage: a prospective randomized clinical and histological study
B Molnár, A K Jung, Z Papp, A Martin, K Orbán, A Pröhl, O Jung, M Barbeck, P Windisch
Study objectives and methods
The present randomized controlled clinical study aimed to investigate if, in lateral maxillary sinus augmentation, the repositioned bony wall or the application of a collagen membrane results in more preferable new hard tissue formation. Forty patients were divided into two study groups. Both groups received a xenogeneic bone substitute material (BSM) during lateral sinus augmentation. In the bony wall group (BW), following piezosurgery, the retrieved bony wall was repositioned. In the collagen membrane group (CM), following rotary instrument preparation, collagen membrane coverage was applied. After 6 months, biopsies were taken to histologically analyze the percentage of BSM, connective tissue (CT), and newly formed bone (NFB) following both approaches.
Results
• Forty implants were placed and 29 harvested biopsies could be evaluated. • Duration of surgery, membrane perforations, and VAS were detected. • Histomorphometrical analysis revealed comparable amounts of all analyzed parameters in both groups in descending order: CT (BW: 39.2 ± 9%, CM: 37,9 ± 8.5%) > BSM (BW: 32.9 ± 6.3%, CM: 31.8 ± 8.8%) > NB (BW: 27.8 ± 11.2%, CM: 30.3 ± 4.5%)..
Conclusions
The results of the present study show that the closure of the access window by means of the retrieved bony wall or a native collagen membrane led to comparable bone augmentation results. Lateral maxillary sinus augmentation with the application of a xenogeneic BSM in combination with a native collagen membrane for bony window coverage represents a reliable method for surgical reconstruction of the posterior maxilla. Piezosurgery with bony window repositioning delivers comparable outcomes without membrane coverage.
Adapted from B Molnár et al., Clin Oral Investig. 2022 May 20, for more info about this publication click HERE
Clin Oral Implants Res. 2022 Jul 16. doi: 10.1111/clr.13976
Dental implants in patients with head and neck cancer - a systematic review and meta-analysis of the influence of radiotherapy on implant survival
E Schiegnitz, K Reinicke, K Sagheb, J König, B Al-Nawas, K A Grötz
Study objectives and methods
The purpose of this meta-analysis was to compare implant survival in irradiated and non-irradiated bone and to investigate potential risk factors for implant therapy in oral cancer patients.
An extensive search in the electronic databases of the National Library of Medicine was performed. Systematic review and meta-analysis were conducted according to PRISMA statement. The meta-analysis was performed for studies with a mean follow-up of at least three and five years, respectively.
Results
• The systematic review resulted in a mean overall implant survival of 87.8% (34-100%). • The meta-analysis revealed a significantly higher rate of implant failure in irradiated bone compared to non-irradiated bone (p<0.00001, OR 1.97, CI [1.63, 2.37]). • The studies also showed that implants placed into irradiated grafted bone were more likely to fail than those in irradiated native bone (p<0.0001, OR 2.26, CI [1.50, 3.40]).
Conclusions
Even though overall implant survival was high, radiotherapy proves to be a significant risk factor for implant loss. Augmentation procedures may also increase the risk of an adverse outcome, especially in combination with radiotherapy.
Adapted from E Schiegnitz et al., Clin Oral Implants Res. 2022 Jul 16, for more info about this publication click HERE
J Clin Periodontol. 2022 May 15. doi: 10.1111/jcpe.13645
Psychological risk indicators for peri-implantitis: A cross-sectional study
H Strooker, Y C M de Waal, M M Bildt.
Study objectives and methods
The aim of this analytical cross-sectional study was to evaluate the association between peri-implantitis and psychological distress, and potentially related/mediating factors such as general health, bruxism, and lifestyle factors.
Patients who received dental implants at a private practice in the Netherlands between January 2011 and January 2014 were recalled on a 5-year clinical and radiographic follow-up examination. Presence of peri-implantitis was examined, and patients completed questionnaires measuring psychological distress (Symptom Checklist [SCL]-90), bruxism, general health, and lifestyle factors. Associations between the self-reported factors and peri-implantitis were analysed with univariate and multivariate logistic regression models.
Results
• A total of 230 patients (with 347 implants) were included in the analysis. • Prevalence of (mild to severe) peri-implantitis was 30% (69 patients). • Variables that showed a significant univariable association with peri-implantitis (p < .10) were the SCL-90 subdomain depression, smoking, current medical treatment, and lung problems. • In the multivariate regression analysis, depression was the only variable that was significantly associated with periimplantitis (p < .05).
Conclusions
The presence of depressive symptoms is a risk indicator for peri-implantitis. Recognizing the potential negative impact of depressive symptoms may allow for better identification of high-risk patients.
Adapted from H Strooker et al., J Clin Periodontol. 2022 May 15, for more info about this publication click HERE
Evid Based Dent. 2022 Jun;23(2):78-80. doi: 10.1038/s41432-022-0266-7
Preoperative administration of amoxicillin is not recommended in healthy patients undergoing implant surgery
K I Afrashtehfar, V B Desai, C D M Afrashtehfar
Study objectives and methods
A multicentre, prospective, randomised, placebo-controlled, double-blinded clinical trial reported the early implant failure and postoperative infections of healthy or relatively healthy patients receiving 2 grams of amoxicillin one hour preoperatively from their scheduled dental implant placement. The registration of the study protocol in EudraCT and Clinical Trials.gov (#NCT03412305) followed the ethical principles of the Declaration of Helsinki and the CONSORT guidelines for clinical trials.
Several trial drugs expired before recruiting the intended 1,000 patients calculated based on previous trials reporting 2% and 5% early implant loss, with and without antibiotic prophylaxis. Thus, the study cohort (age >18 years, not planned for immediate loading, not requiring substantial bone augmentation, with an absence of severe diseases or immunosuppression or immunodeficiency) received 757 implants in total between November 2014 and April 2018, consisting of the prophylactic antibiotic therapy group (patients n = 235) and the placebo group (patients n = 235), with a fair sex distribution and a mean age of 57.4 ± 13.9 years.
A computer-generated list of random numbers assisted the randomisation (test or control group) with a block-size six. For the clinical procedures, bone augmentation was limited to autogenous bone chips and bone debris. One- and two-stage surgery protocols were used in maxillary or mandibular single or multiple dental implants. The utilised implant systems were Straumann SLA (Straumann Implants, Switzerland), Astra Tech Dental Implant Systems (Dentsply Sirona, Sweden), Nobel Biocare (Sweden) and Southern Implants (Ltd, South Africa). Chlorhexidine 0.2% was prescribed preoperatively and/or postoperatively.
Implant failure was the main measured outcome, whereas postoperative infections and adverse events were the secondary outcomes postoperatively assessed at 7-14-day (first follow-up) and 3-6-month (second follow-up) intervals.
The sample size calculation (type one error: 0.05; power: 80%) estimated 500 patients in each group. Proportional differences and relative risk (RR) with a 95% confidence interval (CI) were calculated. Implant failure was the dependent variable for the multiple logistic regression (MLR) model examining the indicator variables smoking (yes or no), and age (<50 years; 50-64; and ≥65), as well as the independent variables bone augmentation (yes or no), number of implants (1, 2-3 and ≥4), and treatment group (antibiotic prophylaxis or placebo). P-values <0.05 or 95% CIs for ratios not including one were deemed statistically significant. The analyses were carried out using statistical software for data science (STATA).
Results
• Overall, six (2.5%) and seven patients (3.0%) from the amoxicillin and placebo groups had implant failures, respectively. Thus, the intergroup difference was not significant (RR: 0.85; 95% CI: 0.29-2.48, p = 0.75). • Absolute risk reduction was 0.46%, with a number needed to treat (NNT) of 219. In other words, one in every 219 patients will benefit from receiving prophylactic antibiotics. • In addition, no variable was associated with implant failure. Two (0.8%) and five patients (2.1%) from the amoxicillin and placebo groups, respectively, had postoperative infections at the first follow-up interval. Thus, the intergroup difference was not significant (RR: 0.29; 95% CI: 0.08-2.01, p = 0.25). • Five (2.1%) and seven patients (3.0%) from the amoxicillin and placebo groups, respectively, had postoperative infections at the second follow-up interval. Thus, the intergroup difference was not significant (RR: 0.70; 95% CI: 0.232.18, p = 0.54). • No adverse events were reported.
