A randomized clinical trial of phycogenic materials for sinus grafting with hydroxyapatite versus biphasic calcium phosphate: 2 years clinical outcomes.

OBJECTIVES: To assess in a prospective randomized trial two phycogenic bone substitutes-biphasic calcium phosphate (BCP) versus almost pure hydroxyapatite (HA)-for their volume stability and clinical implications after sinus floor elevation (SFE). MATERIALS AND METHODS: Twenty patients requiring lateral-window SFE 6 months prior to implant surgery were randomized to a BCP or HA group. As primary outcome, the grafts were analyzed for volume stability, using four cone-beam computed tomography scans obtained immediately/6/12/24 months after SFE. Secondary outcomes were implant survivval, success, periotest values, oral-health-related quality of life (OHIP-G14), and pain (VAS). RESULTS: Kolmogorov-Smirnov goodness-of-fit test revealed normal distribution of samples (p = .200). At 6/12/24 months, the augmented volumes decreased to 96/92/90% (HA) or 99/96/96% (BCP). Volume changes were significantly a factor of time (p < .001; generalized linear model with repeated measures) and reached significantly lower values in HA group (p = .018). Significant intergroup difference in volume losses was notable at 24 months (p = .021; t-test for independent samples). Periotest values decreased from -3/-4.1 (HA/BCP) after implant placement to -6.3/-4.5 (HA/BCP) after 6 months. OHIP scores diverged at 2 months (HA: 9.5; BCP: 5.2) and largely resolved by 24 months (HA: 1.3; BCP: 1.9). VAS scores were comparable, 2.2 at 1 week after SFE being their highest mean level. CONCLUSIONS: After 2 years, both groups experienced no biological or technical complications, demonstrating a consistent healing trajectory without notable symptoms. Although no significant differences were observed in implant stability and survival, BCP demonstrated higher volume stability than HA.

The reliability of using gingival crevicular blood to measure blood glucose and hba1c levels in the dental setting: a systematic review and meta-analysis.

OBJECTIVE: There are 500 million patients living with diabetes mellitus worldwide and 50% of them remain undiagnosed. Routine periodontal probing provides gingival crevicular blood in patients with gingivitis. Gingival blood may be useful for diabetes screening without the need for any expensive, painful or time-consuming method by using convenient glucometers. Therefore, the objective of this systematic review and meta-analysis is to answer the question to "is there a difference in glucose or HbA1c levels (O) in patients with positive gingival bleeding (P) measured on gingival crevicular blood (GCB) (I) compared to finger prick capillary blood (CB) (C). MATERIALS AND METHODS: The authors performed an electronic search of six databases using identical MeSH phrases. Only human clinical studies without limitations on the year of publication were considered. Data extraction was done by using standardized data collection sheets. Risk of bias assessment were conducted using QUADAS-2 and QUADAS-C. Meta-analyses were carried out with the random effects model to aggregate the correlation coefficients and the difference between the means between gingival and capillary blood reading, using 95% confidence intervals. RESULTS: The database and manual search yielded 268 articles, from which the selection procedure provided 36 articles for full-text screening, and the final pool of eligible articles composed of 23 studies with 1680 patients. Meta-analysis results on glycemic levels showed differences between the GCB and CB procedures in patients with and without diabetes with values of -6.80 [-17.35; 3.76] and - 4.36 [-9.89; 1.18], respectively. Statistically significant correlations were found (p = 0.001) between GCB and CB measurements in patients with (0.97 [0.927; 0.987]) and without diabetes (0.927 [0.873; 0.958]). CONCLUSION: Gingival blood could prove to be useful to identify patients with undiagnosed diabetes when the necessary amount of uncontaminated blood is present. However, this technique is limited by the possibility of contamination, prandial status and inaccuracies, so it is unsuited to address the patient's glycemic control accurately.

Evaluation of dental education during the pandemic of COVID-19-Results from an online survey among dental students.

INTRODUCTION: The aim of this study was to assess the students' experience with education during the COVID-19 pandemic, as well as to investigate their views moving forward after resumption of face-to-face education. MATERIALS AND METHODS: A questionnaire was administered to dental students in clinical dental education at seven dental schools. The questionnaire included 33 items organized in three sections: (a) Demographics, (b) Perceptions/activity during lockdown, and (c) Perceptions/activity upon resumption of face-to-face teaching. RESULTS: A total of 286 students from seven universities in Europe and Asia participated. Students' satisfaction with education during the pandemic varied among universities and ranged between 36%-80%, but students engaged in delivering emergency care had a significantly higher opinion (p = .001). Students who felt that their workload decreased, were commonly 24 years old or older (p = .015), male (p = .05) reported lower concentration and motivation, experienced a more severe disruption and valued lower the efforts of their universities to ensure the continuity of education (p = .009). The majority of the students (80.3%) felt confident to resume clinical training after the lockdown. In general, female students experienced a higher disruption of their education during the pandemic (p = .043) and expressed lower confidence to continue clinical training in comparison to their male colleagues (p = .001). CONCLUSION: Students' perception of their workload during the COVID-19 lockdown was very diverse, with those experiencing a reduction in workload being more likely to express lower satisfaction as well. Female students experienced a higher level of disruption. Engaging students in the delivery of emergency care had a positive effect on their appreciation of the education.

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.

Platelet-Rich Fibrin in Oral Surgery and Implantology: A Narrative Review.

Background: The application of blood concentrates has gained popularity in dentistry in recent years. Platelet-rich fibrin (PRF) has been discussed frequently due to a high content of growth factors and the option of chair-side manufacturing in a simple centrifugation process. PRF is free from adjuvants and inexpensive to produce. The number of studies reporting beneficial effects of PRF in various clinical applications such as alveolar ridge preservation, sinus floor elevation, management and prevention of medical-related osteonecrosis of the jaw, third molar extractions, and guided bone regeneration in dentistry has increased recently. However, to date, neither clinical recommendations nor guidelines are available. The present narrative review aims to summarize the level of evidence on the clinical application of PRF within the field of oral surgery and implantology. Summary: A literature search in Pubmed and Medline has identified 34 articles as a basis for this narrative review. The effectiveness of the clinical application of PRF has been analyzed for five indications within dentistry: medical-related osteonecrosis of the jaw, wisdom tooth extraction, guided bone regeneration, sinus floor elevation, and alveolar ridge preservation. The amount of data for third molar extractions, socket preservation, and guided bone regeneration is extensive. Less data were available for the use of PRF in combination with sinus floor elevations. There is a lack of studies with scientific evidence on PRF and medical-related osteonecrosis of the jaw; however, studies positively impact patient-related outcome measures. Most studies report on beneficial effects when PRF is additionally applied in intrabony defects. There is no evidence of the positive effects of PRF combined with bone graft materials during sinus floor elevation. However, some benefits are reported with PRF as a sole filling material. Key Messages: Many recently published studies show the positive clinical impact of PRF. Yet, further research is needed to ensure the validity of the evidence.

Is perioperative antibiotic prophylaxis in the case of routine surgical removal of the third molar still justified? A randomized, double-blind, placebo-controlled clinical trial with a split-mouth design.

INTRODUCTION: Since antimicrobial resistance, caused by various factors including antibiotic overuse and abuse, is a severe challenge, the necessity of perioperative antibiotic prophylactic for surgical third molar removal remains a contentious topic. This study determined whether perioperative antibiotic prophylaxis can reduce surgical site infections (SSIs), swelling, and pain in the case of surgical removal of wisdom teeth. MATERIAL AND METHODS: A randomized, double-blind, placebo-controlled clinical trial with a split-mouth design. A study medication of 2 g amoxicillin, administered 1 h before the third molar removal, followed by 1.5 g each for the first 3 postoperative days, was compared with placebo medication. The primary outcome variable (SSI), secondary clinical parameters (swelling and trismus), and patient-centered outcome measures (bleeding, swelling, pain, and pain medication intake) were documented until postoperative day 7. Statistical analyses were done with a paired t test, t test for independent samples, Chi-square test, and McNemar test, including effect sizes. RESULTS: Primary outcome SSI, in total 11%, and clinical parameters swelling and trismus were not significantly different between the two groups. The patient-centered outcome measures (bleeding, swelling, and pain) did not significantly differ, except for postoperative bleeding in the EG on day 0. No significant result was found with pain medication intake postoperative on days 0-7. CONCLUSIONS: Perioperative administration of oral antibiotics neither revealed additional benefits in patient-related outcome measures nor reduced postoperative complications compared with the placebo group indicated at routine surgical removal of noninflamed wisdom teeth. CLINICAL RELEVANCE: Taking antimicrobial resistance into account, clear recommendations for administering drugs, particularly antibiotics, are critical in oral surgery.

Intravenous ibuprofen versus diclofenac plus orphenadrine in orthognathic surgery: a prospective, randomized, double-blind, controlled clinical study.

OBJECTIVES: The aim of this prospective, randomized, double-blind, controlled clinical study was to evaluate the analgesic effect of ibuprofen versus diclofenac plus orphenadrine on postoperative pain in orthognathic surgery. MATERIAL AND METHODS: Patients who underwent orthognathic surgery were randomized into two groups to receive intravenously either 600 mg of ibuprofen (I-group) or 75 mg diclofenac plus 30 mg orphenadrine (D-group), both of which were given twice daily. Additionally, both groups were given metamizole 500 mg. Rescue pain medication consisted of acetaminophen 1000 mg and piritramide 7.5 mg as needed. To assess the pain intensity, the primary end point was the numeric rating scale (NRS) recorded over the course of the hospital stay three times daily for 3 days. RESULTS: One hundred nine patients were enrolled (age range, 18 to 61 years) between May 2019 and November 2020. Forty-eight bilateral sagittal split osteotomies (BSSO) and 51 bimaxillary osteotomies (BIMAX) were performed. Surgical subgroup analysis found a significant higher mean NRS (2.73 vs.1.23) in the BIMAX D-group vs. I-group (p = 0.015) on the third postoperative day. Additionally, as the patient's body mass index (BMI) increased, the mean NRS (r = 0.517, p = 0.001) also increased. No differences were found between age, gender, length of hospital stay, weight, operating times, number of patients with complete pain relief, acetaminophen or piritramide intake, and NRS values. No adverse events were observed. CONCLUSION: The results of this study demonstrate that ibuprofen administration and lower BMI were associated with less pain for patients who underwent bimaxillary osteotomy on the third postoperative day. Therefore, surgeons may prefer ibuprofen for more effective pain relief after orthognathic surgery. CLINICAL RELEVANCE: Ibuprofen differs from diclofenac plus orphenadrine in class and is a powerful analgetic after orthognathic surgery.

Does the timing of implant placement and loading influence biological outcomes of implant-supported multiple-unit fixed dental prosthesis-A systematic review with meta-analyses.

OBJECTIVE: To investigate the impact of timing of implant placement and loading on implant survival and biological outcomes of multiple-unit implant-supported fixed dental prosthesis (FDPs). MATERIAL AND METHODS: A literature search was performed by three independent reviewers for studies reporting on ≥10 patients with FPDs supported by ≥two implants over ≥3 years of follow-up. Data were analyzed on implant survival and biological complications as primary outcomes and biological events, including changes in peri-implant marginal bone level (MBL), probing depth, soft-tissue level, and health condition as secondary outcomes. RESULTS: 7002 titles were identified, 360 full-texts were screened, and 14 studies were included. These comprised 6 randomized controlled studies (RCTs), 5 cohort studies, and 3 case series with identifiable implant placement and loading protocols in five of 09 possible combinations. All groups but one (IPIL) showed implant survival rates >90%. A meta-analysis based on 3 RCTs found no differences in survival rate between DPIL and DPDL (p = .227). CONCLUSIONS: High survival rates for all studied implant placement and loading combinations were shown for FPDs over ≥3 years of follow-up. When a delayed implant placement protocol is applied, immediate or delayed loading demonstrated similar survival rates. The heterogeneity of the data did not allow to draw any further conclusions on the occurrence of biological complications related to timing of implant placement/loading.

Impact of timing of dental implant placement and loading: Summary and consensus statements of group 1-The 6th EAO Consensus Conference 2021.

OBJECTIVES: This publication reports on the EAO workshop group 1 summaries, discussions and consensus statements based on four systematic reviews evaluating the impact of timing of dental implant placement and loading. MATERIALS AND METHODS: The first of the systematic reviews was on the influence of the timing of implant placement and loading in the biological outcomes of implant-supported fixed partial dentures. The second systematic review evaluated the influence of the timing of implant placement and loading on the aesthetic outcomes in single-tooth implants. The third systematic review was on the long-term outcomes of maxillary single-tooth implants in relation to timing protocols of implant placement and loading and the fourth on patient's perception of timing concepts in implant dentistry. The group evaluated these systematic reviews, provided comments and additions as required and agreed on the relevant consensus statements as well as on clinical and research recommendations. RESULTS: Different timings of implant placement/loading presented with high implant survival rates. The systematic reviews evaluated from this working group provided a number of conclusions based on the available/current literature. However, the specific topic of timing is an area that further research is required in order to provide detailed guidelines for the different protocols to be employed.

Primary bone augmentation leads to equally stable marginal tissue conditions comparing the use of xenograft blocks infused with BMP-2 and autogenous bone blocks: A 3D analysis after 3 years.

OBJECTIVES: To test whether or not primary bone augmentation using xenograft blocks infused with BMP-2 or autogenous bone blocks lead to similar results regarding the implant survival and 3D marginal soft tissue contours. METHODS: Twenty-four patients with an insufficient ridge width for implant placement in need of primary augmentation were randomly assigned to either a block of deproteinized bovine bone mineral infused with rhBMP-2 (BMP) or an intraorally harvested block of autogenous bone (ABB). At 4 months, 1-4 dental implants were placed in the regenerated area. After crown insertion and at 3 years, peri-implant tissue parameters, two- and three-dimensional radiographic parameters, and soft tissue contour changes were evaluated. Explorative mixed model analyses were performed. The level of significance was set at 5%. RESULTS: At the 3-year follow-up, 23 patients with 40 implants were evaluated. The implant survival rate was 100% in both groups. At baseline, the marginal hard tissue levels amounted to -0.4 ± 0.8 mm (mean ± standard deviation) in the BMP group and -0.7 ± 1.0 mm in the ABB group. At 3 years, these values were -0.2 ± 0.4 mm (BMP) and -0.6 ± 1.0 mm (ABB). At baseline, the thickness of the buccal hard tissue at the level of the implant shoulder measured 1.1 ± 1.1 mm (BMP) and 1.4 ± 1.0 mm (ABB). At 3 years, it measured 0.9 ± 0.9 mm (BMP) and 0.7 ± 0.6 mm (ABB). CONCLUSIONS: The present study demonstrated excellent implant survival rates and stable marginal hard tissue levels in both augmentation groups, 3 years after crown insertion. In addition, the clinical stability of soft and hard tissues was demonstrated in both groups.

Two-piece zirconia versus titanium implants after 80 months: Clinical outcomes from a prospective randomized pilot trial.

OBJECTIVES: To prospectively evaluate, as part of an ongoing randomized pilot trial, the clinical outcomes of two-piece zirconia implants in comparison with titanium implants 80 months after delivery of all-ceramic (lithium disilicate) single-tooth restorations. MATERIAL AND METHODS: The original sample included 31 (16 zirconia and 15 titanium) implants in 22 healthy patients. In addition to evaluating implant survival and success, a number of clinical or radiographic parameters were statistically analyzed: plaque index (PI), bleeding on probing (BOP), pink esthetic score (PES), and marginal bone loss (MBL). Both implant groups were compared using a Mann-Whitney U test. RESULTS: Three implants (2 zirconia and 1 titanium) had been lost, so that 28 implants (14 zirconia and 14 titanium) in 21 patients could be evaluated after a mean of 80.9 (SD: 5.5) months. All surviving implants had remained stable, in the absence of any fixture or abutment fractures and without any chipping, fracture, or debonding of crowns. The zirconia implants were associated with PI values of 11.07% (SD: 8.11) and the titanium implants with 15.20% (SD: 15.58), the respective figures for the other parameters being 16.43% (SD: 6.16) or 12.60% (SD: 7.66) for BOP; 11.11 (SD: 1.27) or 11.56 (SD: 1.01) for PES; and 1.38 mm (SD: 0.81) or 1.17 mm (SD: 0.73) for MBL. CONCLUSIONS: No significant differences were found between the clinical outcomes of two-piece zirconia and titanium implants based on the aforementioned parameters after 80 months of clinical service. Our results should be interpreted with the limited sample size in mind.

The effect of systemic antibiotics on clinical and patient-reported outcome measures of oral implant therapy with simultaneous guided bone regeneration.

OBJECTIVES: The aim of the present superiority study was to determine the effect of systemic antibiotics primarily on patient-reported outcome measures (PROMs) and post-surgical complications in patients undergoing oral implant therapy with simultaneous guided bone regeneration (GBR). MATERIALS AND METHODS: A total of 236 medically and periodontally healthy patients received oral implants with simultaneous GBR at seven centres. Pre-operative antibiotics of 2 g amoxicillin were prescribed to the test group 1 hr prior to surgery and 500 mg thrice daily on days 1-3 after surgery. The control group was given a placebo. Group allocation was performed randomly. Primary outcome variables were PROMs recorded as visual analogue scale scores assessed on days 1-7 and 14 on pain, swelling, haematoma and bleeding. Post-operative complications as secondary outcome variables were examined at 1, 2, 4 and 12 weeks from surgery. Chi-square tests and repeated measures of analysis of variance (ANOVA) were performed for statistical evaluation. RESULTS: No statistically significant differences (p > .05) between the two groups were detected for the evaluated PROMs. The same was noted with respect to post-surgical complications. Four implants were lost-three in the test group and one in the control group. CONCLUSION: In this trial, systemic antibiotics did not provide additional benefits to PROMs, nor the prevention of post-surgical complications in medically and periodontally healthy patients undergoing oral implant therapy with simultaneous GBR. However, further studies with larger sample sizes are still required to support the clinical outcomes of this study.

Randomized clinical study using xenograft blocks loaded with bone morphogenetic protein-2 or autogenous bone blocks for ridge augmentation - A three-dimensional analysis.

OBJECTIVES: To test whether or not the use of a xenogeneic block loaded with rhBMP-2 results in superior radiological and profilometric outcomes compared to an autogenous bone block. MATERIALS AND METHODS: Twenty-four patients randomly received a xenogeneic block loaded with rhBMP-2 (test) or an autogenous bone block (control) for primary augmentation. The ridge width (RW) was evaluated by means of a CBCT scan after augmentation surgery and at 4 months, prior to implant placement. Surface scans were taken prior to augmentation and at 4 months for profilometric analyses. Data were analyzed with Wilcoxon-signed rank test, Mann-Whitney test, or nonparametric ANOVA models. RESULTS: The median RW after augmentation amounted to 7.13 mm (Q1 = 6.02; Q3 = 8.47) for test and 6.86 mm (Q1 = 5.99; Q3 = 8.95) for control. During 4 months of healing, the total RW decreased statistically significantly and measured 5.35 mm (Q1 = 4.53; Q3 = 6.7) for test and 5.15 mm (Q1 = 3.57; Q3 = 7.24) for control (p = 0.0005). The differences between the groups were not statistically significant (p > 0.5899). The buccal soft tissue contour slightly increased for test (0.83 mm; Q1 = 0.62; Q3 = 1.87) and control (1.16 mm; Q1 = 0.50; Q3 = 1.44). CONCLUSIONS: Both treatment modalities successfully increased the ridge width to a similar extent. The shrinkage during healing was not greater in the test than in the control group. The impact of hard tissue augmentation on the soft tissue contour was, however, minimal.

Accuracy assessment of 3D-printed tooth replicas.

AIM: The production of individual tooth replicas has two applications in dental practice: tooth autotransplantations and dental root analogue implants. These applications require a particularly high degree of precision. The purpose of this study was to establish and evaluate a method for fabricating individual 3D-printed tooth replicas. MATERIALS AND METHODS: 10 patients requiring extraction of a wisdom tooth and a preoperative cone beam computed tomography (CBCT) scan were included; exclusion criteria were intraoperative fragmentation or fracture of the tooth. 3D Slicer 4.6.2 was used for tooth segmentation and model generation based on CBCT data. The tooth replicas were manufactured by selective laser melting (SLM). The extracted teeth and 3D-printed replicas were scanned and tested for surface deviations in CloudCompare 2.8.1. RESULTS: The mean absolute surface deviation between the 3D-printed teeth and the corresponding extracted teeth ranged from 0.13 to 0.25 mm, with standard deviations of 0.10 to 0.21 mm; 95% of the measured surface points deviated less than 0.474 mm; the surface area was reduced by -6.0% and the volume by -3.4%. The root mean square was 0.238 mm and the mean maximum absolute surface deviation was 0.927 mm. The SLM technique showed a high precision with a mean absolute deviation of 0.045 mm and a standard deviation of 0.04 mm. CONCLUSION: 3D-printed tooth replicas with a very high accuracy could be produced based on CBCT data. The described method is suitable for manufacturing tooth replicas for use in tooth autotransplantations or for fabricating root analogue implants.

Randomized, controlled clinical two-centre study using xenogeneic block grafts loaded with recombinant human bone morphogenetic protein-2 or autogenous bone blocks for lateral ridge augmentation.

OBJECTIVES: To test whether or not the use of a xenogeneic block loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2) results in different bone quantity and quality compared to an autogenous bone block. MATERIALS AND METHODS: Twenty-four patients with insufficient bone volume for implant placement were randomly assigned to two treatment modalities: a xenogeneic bone block loaded with rhBMP-2 (test) and an autogenous bone block (control). The horizontal ridge width was evaluated prior to augmentation, after augmentation and at 4 months. Patient-reported outcome measures (PROMs) were assessed at suture removal and at 4 months. Biopsies were obtained at 4 months and histologically evaluated. Intergroup comparisons were tested by a two-sided Wilcoxon-Mann-Whitney test, intra-group comparisons were performed with Wilcoxon-signed rank test, and all categorical variables were tested with Chi-squared tests. RESULTS: One autogenous bone block failed. This patient was replaced, and in all subsequently treated 24 patients, implant placement was possible 4 months later. The median ridge width increased from 4.0 mm (Q1 = 2.0; Q3 = 4.0) (test) and 2.0 mm (Q1 = 2.0; Q3 = 3.0) (control) to 7.0 mm (Q1 = 6.0; Q3 = 8.0) (test) and 7.0 mm (Q1 = 6.0; Q3 = 8.0) (control) at 4 months (intergroup p > .05). A higher morbidity was reported at the augmented site in the control group during surgery. Sensitivity was more favourable in the test than that in the control group at 4 months. The biopsies revealed more mineralized tissue in the control group (p < .0043). CONCLUSIONS: Both treatment modalities were successful in regenerating bone to place dental implants. PROMs did not reveal any significant differences between the groups except for pain during surgery at the recipient site (in favour of the test group). Histologically, a higher amount of mineralized tissue was observed for the control group at 4 months.

Group 1 ITI Consensus Report: The influence of implant length and design and medications on clinical and patient-reported outcomes.

OBJECTIVES: The aim of Working Group 1 was to address the influence of different local (implant length, diameter, and design) and systemic (medications) factors on clinical, radiographic, and patient-reported outcomes in implant dentistry. Focused questions on (a) short posterior dental implants (≤6 mm), (b) narrow diameter implants, (c) implant design (tapered compared to a non-tapered implant design), and (d) medication-related dental implant failures were addressed. MATERIALS AND METHODS: Four systematic reviews were prepared in advance of the Consensus Conference and were discussed among the participants of Group 1. Consensus statements, clinical recommendations, and recommendations for future research were based on structured group discussions until consensus was reached among the entire expert Group 1. The statements were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Short implants (≤6 mm) revealed a survival rate ranging from 86.7% to 100%, whereas standard implant survival rate ranged from 95% to 100% with a follow-up from 1 to 5 years. Short implants demonstrated a higher variability and a higher Risk Ratio [RR: 1.24 (95% CI: 0.63, 2.44, p = 0.54)] for failure compared to standard implants. Narrow diameter implants (NDI) have been classified into three categories: Category 1: Implants with a diameter of <2.5 mm ("Mini-implants"); Category 2: Implants with a diameter of 2.5 mm to <3.3 mm; Category 3: Implants with a diameter of 3.3 mm to 3.5 mm. Mean survival rates were 94.7 ± 5%, 97.3 ± 5% and 97.7 ± 2.3% for category 1, 2 and 3. Tapered versus non-tapered implants demonstrated only insignificant differences regarding clinical, radiographic, and patient-reported outcomes. The intake of certain selective serotonin reuptake inhibitors and proton pump inhibitors is associated with a statistically significant increased implant failure rate. The intake of bisphosphonates related to the treatment of osteoporosis was not associated with an increased implant failure rate. CONCLUSIONS: It is concluded that short implants (≤6 mm) are a valid option in situations of reduced bone height to avoid possible morbidity associated with augmentation procedures; however, they reveal a higher variability and lower predictability in survival rates. Narrow diameter implants with diameters of 2.5 mm and more demonstrated no difference in implant survival rates compared to standard diameter implants. In contrast, it is concluded that narrow diameter implants with diameters of less than 2.5 mm exhibited lower survival rates compared to standard diameter implants. It is further concluded that there are no differences between tapered versus non-tapered dental implants. Certain medications such as selective serotonin reuptake inhibitors and proton pump inhibitors showed an association with a higher implant failure rate.

Attachment and growth of human osteoblasts on different biomaterial surfaces.

OBJECTIVES: To prove the biocompatibility of biomaterials applied in biomedical devices, in vitro testing is crucial to render a material fit for medical application. The material of choice for dental implants is commercially pure titanium (cp-Ti), while other materials such as zirconia and polyetheretherketone (PEEK) are considered highly promising due to their functional and esthetic properties. The aim of this study was to determine whether PEEK with defined mean surface roughness and composition could achieve results equal to titanium or zirconia. MATERIALS AND METHODS: Disks measuring 14 mm in diameter and 1 mm in thickness made from cp-Ti, yttria-stabilized zirconia (Y-TZP), and filled PEEK with a smooth surface finish were used for cell culture experiments. Human fetal osteoblasts (hFOB) were cultured in vitro on each material to observe changes after 1, 3, and 7 days regarding cell viability and lactate dehydrogenase (LDH) release. Additionally, mRNA expression of proliferative factors PCNA and Ki67 and cellular adhesion (vinculin mRNA expression and immunofluorescence staining) were analyzed after 3 days in the culture. RESULTS: In hFOB cultures, adhesion and viability were decreased on PEEK platelets, while LDH release remained stable. No significant difference was observed in cp-Ti and Y-TZP when compared to the control. CONCLUSIONS: The performance of cp-Ti and Y-TZP was equal to the control in all tests. It seems that highly polished PEEK in this particular composition cannot be recommended for osseointegrated implant applications due to decreased osteoblast attachment. Further investigations are recommended, especially in surface structures optimized for osseointegration.

Effect of double conical abutment screw on implant preload.

OBJECTIVE: This study compared the loosening torque of experimental double conical abutment screws to that of conventional conical abutment screws and flat-head screws in implants with internal connections before and after mechanical loading. MATERIAL AND METHODS: Eighty implant-screw-abutment assemblies were divided into four groups: flat-head screw (Xive S), conical screw (Straumann), conical screw (Nobel Biocare), and double conical screw (RTB). Abutments were tightened to a torque of 30 Ncm. After 10 min, they were retightened and loosening torque was measured. The same abutments were then retightened with new screws to a torque of 30 Ncm and, again, retightened after 10 min. They were then mechanically loaded for 3 000 000 cycles, and loosening torque was again measured. Data were collected, and an exploratory analysis was performed. RESULTS: Comparisons before mechanical cycling showed significant differences between groups. After mechanical cycling, only the comparisons of Straumann and Nobel Biocare showed no significant differences. Considering the same group before and after mechanical cycling, all comparisons showed significant differences. CONCLUSION: The shape of the abutment screw head significantly influenced loosening torque: Double conical-head screws showed significantly higher loosening torque values than conical-head screws. Conical-head screws showed higher loosening torque values than conventional flat-head screws before and after loading.

Detection of peri-implant bone defects with different radiographic techniques - a human cadaver study.

OBJECTIVES: Two- and three-dimensional radiographic techniques are available to determine peri-implantitis-related bone loss around dental implants. PURPOSE: To compare the performance of detecting different peri-implant bone defects in intraoral radiography (IR), panoramic radiography (PR), Cone Beam Computer Tomography (CBCT) and Computer Tomography (CT). MATERIAL AND METHODS: Six implants were inserted under ideal conditions into the lower jaw of an edentulous human cadaver. IR, PR, CBCT and CT were performed. Two-wall, three-wall and four-wall defects with 1 mm depth were artificially created around two of the implants (one anterior and one posterior), and radiographies were repeated. The identical set-up was used for 3-mm-deep bone defects. All images were presented to seven observers. Sensitivity (SN) and specificity (SP) were determined for each modality, defect type and depths, and likelihood ratios were calculated. RESULTS: The highest sensitivity was found with IR and CBCT for 1 mm (0.67; 0.68) and 3-mm defects (0.81; 0.79). The highest specificity was found with IR for both defect depths (0.51). The best classification of defect type revealed PR for both 1-mm and 3-mm-deep defects. Both likelihood ratios (LR+ and LR-) were best for IR with 1-mm (1.37 and 0.65) and with 3-mm defects (1.65 and 0.37). CONCLUSIONS: IR should still be recommended as favourable method evaluating bone loss around dental implants, while CT demonstrated the lowest performance in detecting peri-implant bone defects.

Surgical management of thoracic idiopathic spinal cord herniation. Technical case report and review.

Idiopathic spinal cord herniation (ISCH) is a rare spinal disease, in which chronic cerebrospinal fluid pulsations push the arachnoid and adjacent thoracic spinal cord region through an antero-lateral dural defect of congenital, post-traumatic, or inflammatory/erosive origin. Symptomatic patients commonly present around the 5th decade of life with slowly progressive myelopathy. Diagnosis relies on high-resolution magnetic resonance imaging. Stable mild cases may be observed, whereas in progressive symptomatic situations, surgical spinal cord reposition and dural defect repair with a dural patch is the preferred treatment. We present a case of ISCH at T5/6 and a review the literature.