Minimally Invasive Treatment of Lateral Incisors with Guided One-Piece or Two-Piece Titanium-Made Narrow Diameter Implants: A Retrospective Comparative Study with Up to Two Years Follow-Up

Restoring teeth with dental implants has become the gold standard in recent years, especially in the esthetic zone. However, limited amount of available bone as well as limited interdental space in the anterior zone may create problems for implant treatment. Narrow diameter implants (NDI) may be a treatment option to resolve the above-mentioned limitations and providing minimally invasive implant therapy without additional regenerative procedures. In this retrospective study, a comparison of clinical and radiographic outcomes between one-piece and two-piece titanium-made NDIs was done with the follow-up of two years after loading. Twenty-three NDI cases were analyzed, 11 in the one-piece implant group (group one) and 12 in the two-piece implant group (group two). The outcomes were implant and prosthetic failures, any complications occurred, peri-implant bone level changes, and as well as the Pink Esthetic score. No implant or prosthetic failures, as well as, no complications were reported at the two-year follow-up examination. At the same time the marginal bone loss was 0.23 ± 0.11 in the group one and 0.18 ± 0.12 in the group two. Difference was not statistically significant (p = 0.3339). The Pink Esthetic Score, recorded two years after definitive loading, was 12.6 ± 0.97 in the group one and 12.2 ± 0.92 in the group two, with no statistically significant difference between groups (p = 0.3554). With the limitations of the present study, including the small sample size and short follow-up, it is possible to conclude that either one and two-piece NDI can be successfully used to restore lateral incisors with comparable results within the two years of follow-up.

Five-Year Prospective Study on Implant Failure and Marginal Bone Remodeling Expected Using Bone Level Implants with Sandblasted/Acid-Etched Surface and Conical Connection

OBJECTIVE

 The purpose of the present prospective, case-series study was to report implant survival rate and marginal bone remodeling expected 5 years after loading using dental implants placed in daily practice.

MATERIALS AND METHODS

 This research was designed as an open-cohort, prospective, case-series evaluation. Any partially or completely edentulous patient, scheduled to receive at least one bone level implant, was considered eligible for this study. Primary outcome measurements were: implant and prosthetic cumulative survival rate and any complications experienced up to the 5-year follow-up. Secondary outcome measures were: thickness of gingival biotype, implant insertion torque, implant stability quotient, and marginal bone loss (MBL).

RESULTS

 Ninety consecutive patients (34 males and 56 females, aged between 24 and 81 years old [mean: 53.2 ± 15.4]) with 243 inserted implants were followed for at least 5 years after loading (mean: 65.4 ± 3.1 months; range from 60 to 72). At the 1-year follow-up, no drop-outs were recorded, but 17 patients (18.9%) with 18 restorations (12.6%) delivered on 34 implants (14%) were lost at the 5-year examination. At the 5-year follow-up examination, six implants lost osseointegration (97.5%). In the same period, four prostheses failed (97.2%). Five complications were reported in five different patients (prosthetic success rate was 96.5%, at patient level). Five years after loading, the mean MBL was 0.41 ± 0.30 mm. The difference from the 1-year data was 0.04 ± 0.19 mm. A statistically significant higher MBL was found for smokers, and patients with thin gingival biotype. The mean implant insertion torque was 42.9 ± 4.8 Ncm (range from 15 to 45 Ncm). Two-hundred and three implants (83.5%) were inserted with an insertion torque ≥35 and ≤45 Ncm.

CONCLUSIONS

 High implant survival and success rate could be expected with stable marginal bone remodeling up to 5 years after loading. Smoking and thin tissue biotype were the most important variabilities associated with higher MBL. Further research studies are needed to confirm these results.

Histological and Histomorphometric Evaluation of Post-Extractive Sites Filled with a New Bone Substitute with or without Autologous Plate Concentrates: One-Year Randomized Controlled Trial

The purpose of the present study was to evaluate the histological and histomorphometric characteristics of post-extraction sites grafted with decellularized bovine compact bone from bovine femur, mixed and unmixed with leukocyte- and platelet-rich fibrin after four months of healing. This study was designed as a randomized controlled trial of parallel groups. Patients in need of a single, implant-supported restoration to replace a hopeless tooth were recruited for tooth extraction and implant placement four months after socket preservation procedure. After tooth extraction, patients were randomly allocated to receive decellularized bovine compact bone from bovine femur, mixed and unmixed with leukocyte- and platelet-rich fibrin. After four months of healing, tapered implants were inserted with an insertion torque between 35 and 45 Ncm. Two months later, implants were loaded with screw-retained definitive crowns. Outcome measures were implant (ISR) and prosthesis (PSR) survival rates, complications, histological and histomorphometric analyses, radiographic marginal bone-level changes, and patients' satisfaction. Clinical data were collected up to one year after tooth extraction and socket preservation procedures. Thirty patients were consecutively enrolled in the trial (15 in each group). Unfortunately, due to the COVID-19 pandemic, bone samples were collected only in 19 patients. Two implants failed before definitive prosthesis delivery (ISR 93.3%). No prosthesis failed (PSR 100%). Three complications were experienced in the control group. The mean bone percentage was 40.64 ± 18.76 in the test group and 33.40 ± 22.38 in the control group. The difference was not statistically significant (p = 0.4846). The mean soft tissue percentage was 32.55 ± 19.45 in the test group and 55.23 ± 17.64 in the control group. The difference was statistically significant (p = 0.0235). The mean residual graft was 24.59 ± 18.39 in the test group and 11.37 ± 12.12 in the control group. The difference was not statistically significant (p = 0.0992). Mean marginal bone loss, as well as patient satisfaction, showed no differences between groups. With the limitations of the present study, socket preservation with L-PRF mixed with decellularized bovine compact bone demonstrated favorable results, comparing with decellularized bovine compact bone from bovine femur alone. Further studies with larger sample size and longer follow-up are needed to confirm these preliminary results.

Accuracy of surgical templates with and without metallic sleeves in case of partial arch restorations: A systematic review

INTRODUCTION

The aim of the present systematic review was to evaluate whether there were any differences in the three-dimensional accuracy and the implant survival rate of implants placed using computer-assisted planning and surgical templates with or without metallic sleeves.

SOURCES

This systematic review was written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered to the PROSPERO (International prospective register of systematic reviews) database.

STUDY SELECTION

PICOS (population, intervention, control, outcomes, and studies) question was assessed, too. Search strategy encompassed the online (MedLine) literature from 1990 up to December 2020 published in English, and evaluating the accuracy of surgical templates with and without metallic sleeves in partial or complete patients. Only in vivo, randomized controlled trial and observational studies were included. Quality assessment of selected full text articles was performed according to the CONSORT (CONsolidated Standards of Reporting Trials) and STROBE (Strengthening the Reporting of Observational studies in Epidemiology) statement guidelines, respectively. For data analysis, the three-dimensional accuracy and the overall implant survival rate was calculated and compared between implants placed using surgical templates with or without metallic sleeves.

DATA

A total of 12 articles fulfilled the inclusion/exclusion criteria. Data from 264 patients with 614 implants were subjected to quality assessment (templates with metallic sleeves: 279 implants and 136 patients; templates without metallic sleeves: 335 implants and 128 patients). In all the three deviation parameters (angular, vertical, and horizontal), the differences in average accuracy were noticed (angular 2.33° ± 2.01° versus 3.09° ± 1.65°, vertical: 0.62 ± 0.36 [mm] versus 0.95 ± 0.42 [mm]; and horizontal: 0.62 ± 0.41 [mm] and 1.11 ± 0.57 [mm]. No differences was found regarding overall implant survival rate (0.4891).

CONCLUSIONS

With the limitations of the present study, the surgical templates without metallic sleeves demonstrated high level of accuracy in all the three-dimensional measurements, when used to rehabilitate partially edentulous patients. Further randomized controlled trials, reporting according to the CONSORT guidelines are needed to confirm that the differences in accuracy depended on the type of used templates.

1-Year Evaluation of OT Bridge Abutments for Immediately Loaded Maxillary Fixed Restorations: A Multicenter Study

Objective  Preliminary data on survival and success rates of immediately loaded, maxillary, screw-retained, implant-supported, fixed restorations delivered on narrow and low-profile OT Equator abutments (OT Bridge, Rhein’83) were evaluated.

Materials and Methods  This retrospective study evaluated data collected from patients rehabilitated with OT Bridge prosthetic concept between November 2017 and February 2019 in six different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index.

Results  A total of 76 implants were inserted in 14 patients. Patients were followed for a mean period of 15.8 months (range = 12–24). All the patients receive OT Equator (Rhein'83) as intermediate abutments. One year after loading, one implant failed (1.3%). None of the prosthesis failed. One prosthetic complication was experienced in one patient. Three out of 76 implants were connected to the prosthetic framework using only the Seeger system, without screw. Difference in OHIP values was statistically significant (71.9 ± 8.5; p = 0.000). One year after loading, MBL was 0.21 ± 0.11 mm and p- value was 0.000. One year after loading, 8.7% of the examined implant sites present positive bleeding on probing, while 6.4% of the implant sites presented plaque.

Conclusion  The OT Equator abutments (Rhein'83) showed successful results when used to support maxillary fixed dental prosthesis delivered on four to six implants. High implant and prosthetic survival rates, very low complications, high patient satisfaction, and good biological parameters, including only 0.2 mm of bone remodeling were experienced one year after function. Further studies are needed to confirm these preliminary results.

In vitro evaluation of bioburden, three-dimensional stability, and accuracy of surgical templates without metallic sleeves after routinely infection control activities

BACKGROUND

Surgical templates are classified as noncritical devices, and they do not need to be sterile.

AIM

Primary aim of this study was to assess the microbiological burden present on the surgical templates without metallic sleeves after disinfection. Furthermore, to evaluate trueness after disinfection and steam sterilization at 121°C/15 min, and over a 8-week storage period. Finally, to assess their accuracy after in vitro implant placement simulation.

MATERIALS AND METHODS

Forty surgical templates were printed and divided in five groups of eight templates each. Groups A to C were disinfected with 0.5% Chlorhexidine Gluconate and 70% ethyl alcohol base solution for 15 min. Templates in the group D were steam sterilized at 121°C for 15 min, while, the templates in the group E were used as control. Implant simulation was performed in the group A. Outcome measures were determination of bioburden, trueness assessment using GOM Inspect Professional software, and accuracy evaluated thought the mean angular deviation of simulated implants.

RESULTS

Total microbic charge measured as colony forming units (CFU) for sample, was 24.40 in the control group (group E; n = 8), and <4.40 in the test group (group C; n = 8), with a reduction of 84%. Colored representation from GOM inspection showed no differences after disinfection and implant simulation, disinfection alone, and steam sterilization, compared to the control group. A very small difference in the surface and volume dimensions was reported 1 month after templates fabrication. The mean roundness tolerances of the tested templates improved of 0.96 ± 0.56° (95% CI 0.57-1.35).

CONCLUSION

Surgical templates without metallic sleeves can be safely used after disinfection, demonstrating high level of accuracy, even when the surgical procedures should be postponed within a couple of weeks. Further in vivo study are needed to confirm these preliminary results.

Implant Placement Following Crestal Sinus Lift with Sequential Drills and Osteotomes: Five Years after Final Loading Results from a Retrospective Study

The aim of this retrospective study was to clinically evaluate the five-year outcomes of implants placed following a combined approach to the sinus, consisting of sequential drills and osteotomes. Medical records of patients with implants placed in combination with crestal sinus lift using sequential drills and osteotomes, with a residual alveolar bone crest between 4 to 8 mm, and a follow-up of at least five years after final loading, were evaluated. Outcomes were implant and prosthetic survival and success rates, any complication, and marginal bone loss. Data from 96 patients (53 women and 43 men; mean age 54.7 years; range 23-79 years) were collected. A total of 105 single implants were analyzed. After five years of function, two implants were lost and two prostheses failed. No major biological or prosthetic complications occurred. At the five-year examination, the marginal bone loss was 1.24 ± 0.28 mm. Within the limitations of this retrospective study it can be concluded that implants placed following a combined approach to the sinus consisting of sequential drills and osteotomes seem to be a viable option for the treatment of posterior atrophic edentulous maxilla.

Three-Year Retrospective Comparative Study between Implants with Same Body-Design but Different Crest Module Configurations

Crest module can be defined as the portion of a two-piece implant designed to retain the prosthetic components and to allows the maintenance of the peri-implant tissues in the transition zone.

AIM

To evaluate the three-year after loading clinical and radiographic data, collected from patients that received a prosthetic rehabilitation on conical connection implants with partial machined collar (PMC; CC Group) and same body-designed implants, with flat-to-flat connection and groovy neck design (FC Group).

MATERIALS AND METHODS

A retrospective chart review of previously collected data, including documents, radiographs, and pictures of patients who received at least one implant-supported restoration on NobelReplace CC PMC or NobelReplace Tapered Groovy implants was performed. Patients with at least three years of follow-up after final loading were considered for this study. Outcomes measures were implant and prosthesis failures, any biological or technical complications, marginal bone loss.

RESULTS

Eight-two patients (44 women, 38 men; average age 55.6) with 152 implants were selected and divided in two groups with 77 (CC group) and 75 (FC group), respectively. Three years after final loading, one implant in CC group failed (98.7% survival rate), while no implants failed in FC group (100% survival rate). One restoration failed in CC group (98.7% survival rate) with no restoration failing in the FC one (100% survival rate). Differences were not statistically significant (p = 1.0). Three years after final loading, mean marginal bone loss was 0.22 ± 0.06 mm (95% CI 0.2-0.24) in CC group and 0.62 ± 0.30 mm (95% CI 0.52-0.72) in FC group. The difference was statistically significant (0.40 ± 0.13 mm; 95% CI 0.3-0.5; p = 0.003).

CONCLUSION

with the limitation of this retrospective comparative study, implants with conical connection and partial machined collar seem to achieve a trend of superior outcomes if compared with implants with flat connection and groovy collar design.

Coronavirus Disease 2019 Coexistence in the Daily Practice

The purpose of the present narrative review was to evaluate and discuss the actual available information regarding coronavirus disease 2019 and dental practice, and to share recommendations with the intent to help dentists in providing a safe and healthful workplace during pandemic. A step-by-step workflow is presented including prevention and measures to reduce risk for cross infections before, during, and after the dental treatments. Individualization of different risk-level zones and the establishment of a team-based chain control is also presented. The present manuscript may offer deeper knowledge and discussion regarding recommended procedures aimed to reduce risk for dental health care workers contamination and cross infections. Within these, infection prevention in dental settings, respect of general rules, containment measures, proper use of the personal protective equipments (PPE), and well-organized chain control of all the staff, with definition of risk zones and specific responsibility could be an adjunctive but important step to control the spread of the disease.

Role of New Hydrophilic Surfaces on Early Success Rate and Implant Stability: 1-Year Post-loading Results of a Multicenter, Split-Mouth, Randomized Controlled Trial

OBJECTIVE

 To compare early implant failure and implant stability of one-stage Hiossen ET III implants with its new hydrophilic (NH) surface, compared with Hiossen ET III implants with the sandblasted and acid-etched (SA) surface at 1-year follow-up.

MATERIALS AND METHODS

 This study was designed as a split-mouth, multicenter randomized controlled trial aimed to compare SA surface implants (SA group) and NH surface, (NH group). Outcomes were implant and prosthetic survival rates, complications, the insertion torque at implant placement, and implant stability quotient (ISQ) values.

RESULTS

 Twenty-nine patients (mean age 59.9 ± 11.3 years) were treated and followed up to 1 year after loading. No patient dropped out. Fifty-eight implants (29 SA group and 29 NH group) were placed. No implants or prostheses failed and no complications were experienced during follow-up. The mean insertion torque was 40.5 ± 3.23 (38.17-41.83) Ncm in the SA group and 40.48 ± 3.49 (38.02-41.98) Ncm in the NH group (p = 0.981). There was a statistically significant difference at the second week (T2) with higher values in the NH group (p = 0.041). Similar results were found in the maxilla (p = 0.045), but not in the mandible (p = 0.362). A positive correlation was found between initial insertion torque and ISQ with higher value in the NH group (0.73 vs. 0.66).

CONCLUSIONS

 NH implants are a viable alternative to SA surface, as they seem to avoid the ISQ drop during the bone remodeling phase.

Customized 3D-Printed Titanium Mesh Developed to Regenerate a Complex Bone Defect in the Aesthetic Zone: A Case Report Approached with a Fully Digital Workflow

Alveolar-ridge augmentation, anterior aesthetics, and digital technologies are probably the most popular topics in the dental-implant field. The aim of this report is to present a clinical case of severe atrophy of the anterior maxilla in a younger female patient, treated with a titanium membrane customized with computer-aided design/computer-aided manufacturing (CAD/CAM), simultaneous guided implant placement, and a fully digital workflow. A young female patient with a history of maxillary trauma was treated and followed-up for 1 year after implant placement. A narrow implant was inserted in a prosthetically driven position with the aid of computer-guided surgery. In the same surgical section, a customized implantable titanium mesh was applied. The scaffold was designed according to the contralateral maxillary outline in order to recreate a favorable maxillary bone volume. Finally, highly aesthetic, CAD/CAM, metal-free restorations were delivered using novel digital technologies.

Platform switching versus regular platform single implants: 5-year post-loading results from a randomised controlled trial

PURPOSE

To compare the clinical and radiographic outcomes of platform switching (PS) and regular platform (RP) implants.

MATERIALS AND METHODS

This study was designed as a randomised controlled split-mouth trial. Eighteen patients, with bilaterally missing single premolars or molars to be restored with implant-supported single crowns, were consecutively enrolled. Implant sites were randomly assigned to be treated according to the PS concept (PS group), or with matching implant-abutment diameters (RP group). A total of 36 implants were placed in healed bone, with an insertion torque between 35 and 45 Ncm, according to a one-stage protocol. All the implants were loaded with a screw-retained provisional crown 3 months after implant insertion. Definitive screw-retained single crowns were delivered 2 months later. Outcome measures were implant and prosthetic survival rates, biological and prosthetic complications, marginal bone level (MBL) changes, pocket probing depth (PPD) and bleeding on probing (BOP). Clinical data were collected at implant placement (baseline), implant loading (3 months later) and at 9, 36 and 60 months after loading.

RESULTS

One patient dropped out after 4 years of follow-up. No implant failed and no prosthetic complications were recorded during the study period. One patient experienced mucosal inflammation with positive BOP (RP group) after 3 months and three patients had bilateral peri-implant mucosal inflammation with positive BOP at 6, 24 and 36 months, respectively. No other biological complications were recorded up to 60 months of follow-up. There were no statistically significant differences between groups for complications (3/18 versus 4/18; P = 1.0). Nine months after loading the mean MBL was 0.93 ± 0.26 mm (95% CI 0.81 to 1.05) for RP implants and 0.84 ± 0.23 mm (95% CI 0.73 to 0.95) for PS implants. No statistically significant difference was observed between the groups (P = 0.18). Thirty-six months after loading, the mean MBL was 1.09 ± 0.31 mm (95% CI 0.95 to 1.24) in the RP group and 1.06 ± 0.24 mm (95% CI 0.94 to 1.17) in the PS group, with no statistically significant difference between groups (P = 0.70). Sixty months after loading the mean MBL was 1.24 ± 0.39 mm (95% CI 1.05 to 1.43) in the RP group and 1.20 ± 0.21 mm (95% CI 1.01 to 1.39) in the PS group, with no statistically significant difference between the groups (P = 0.85). The mean PPD was 2.58 ± 0.58 mm (95% CI 2.32 to 2.84) in the RP group and 2.40 ± 0.72 mm (95% CI 2.21 to 2.59) in the PS group at 60 months follow-up, with no statistically significant difference between the groups (P = 0.49). The mean BOP was 0.90 ± 0.88 (95% CI 0.58 to 1.22) in the RP group and 0.93 ± 0.97 (95% CI 0.51 to 1.35) in the PS group at 60 months of follow-up, with no statistically significant difference between the groups (P = 0.85).

CONCLUSIONS

Implants restored according to the PS concept and matching implant-abutment diameters showed comparable clinical and radiographic results up to 5 years after loading.

Patient-centered rehabilitation of single, partial, and complete edentulism with cemented- or screw-retained fixed dental prosthesis: The First Osstem Advanced Dental Implant Research and Education Center Consensus Conference 2017

The aim of this consensus conference was to provide clinical guidelines, based on the available evidence and on the author's daily practice and experience, for general dentistry and dental practitioners to allow them to delivery long-term successful restorations. Three groups of expert clinicians and dental technicians were invited to evaluate all of the scientific literature from 1967 up to March 2017 to identify relevant studies on assigned topics and to prepare in advance narrative/systematic review, written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, to fulfill the consensus statement criteria. The three topics assigned to the three groups were abutment/framework materials and customization (metal vs. metal-free restorations), abutment/framework protocols and designs, and abutment/framework retentions (cemented- vs. screw-retained implant-supported prostheses). All the expert clinicians presented their results, and the lectures were followed by discussions. No significant differences in clinical parameters (marginal bone loss, bleeding on probing, and pocket probing depth) between screw- or cemented-retained were found for single and multiple implant-supported restorations. There is moderate evidence that nonoriginal abutments provide worse mechanical behavior than originals and high evidence that different implant neck designs do not offer any clinical or radiographic advantage. All the participants agreed that it is desirable to connect and remove abutments as few times as possible. There is medium evidence that an adequate platform switching tends to enhance tissue volume and stability in the medium- and long-term follow-up. No statistically significant differences exist between metal and zirconia as a framework material. The authors discussed and all agreed that retrievability and patient's expectation (function and esthetics) should guide the choice of the most adequate technique, component, and material.

Do the New Hydrophilic Surface Have Any Influence on Early Success Rate and Implant Stability during Osseointegration Period? Four-Month Preliminary Results from a Split-Mouth, Randomized Controlled Trial

OBJECTIVE

The objective of this study is to compare the implant stability of Hiossen ET III implants with its new hydrophilic (NH) surface and Hiossen ET III implants with the sandblasted and acid-etched (SA) surface.

MATERIALS AND METHODS

Patients required at least two teeth to be rehabilitated with a fixed, implant-supported restoration, consecutively enrolled. Patients randomly received SA surface implants (SA group) or SA implants with a newly developed bioabsorbable apatite nanocoating (NH group). Outcome measures were implant and prosthetic survival rate, complications, insertion torque, and implant stability quotient (ISQ) measured at implant placement and every week up to 8 weeks after implant placement. Comparison between groups was made by unpaired t-test, while the comparison between each follow-up will be made by paired t-tests to detect any change during the follow-up. Complications and failures were compared using Fisher's exact test.

RESULTS

A total of 14 patients were treated with 28 implants (14 SA and 14 NH). No implant and prosthesis failed 4 months after implant placement. No complications were experienced. At the 2nd week after implants placement, two implants in the SA group showed discontinuous measurements versus none in the NH group (p = 0.4815). Implants unscrewed during ISQ measurements and were rescrewed. Data recording stopped for 6 weeks. Both implants osseointegrated without any further complication. The NH implants did not show physiological ISQ decrease between 2nd and 4th week after implant placement, showing a more even pattern of ISQ values compared with SA implants (77.1 ± 4.6 vs. 72.9 ± 11.5; difference: 4.2 ± 12.1; p = 0.258). High ISQ values were found in both groups at each time point.

CONCLUSIONS

NH implants are a viable alternative to SA surface, as they seem to avoid the ISQ drop during the remodeling phase.

Effect of Simultaneous Immediate Implant Placement and Guided Bone Reconstruction with Ultra-Fine Titanium Mesh Membranes on Radiographic and Clinical Parameters after 18 Months of Loading

Background: The aim of the present prospective case series study was to evaluate the implant and prosthetic survival rates, complications and marginal bone loss using ultra-fine titanium mesh membrane with simultaneous implant placement, to provide space maintenance mandatory for guided bone reconstruction of alveolar bone defects. Materials and Methods: patients were recruited and treated at a private clinic in Rome, Italy, between March 2016 and October 2017. Self-tapping tapered implants were placed through a computer-guided template-assisted approach. Autogenous bone was placed alone over the exposed implant surface, then mixed with inorganic bovine bone material. Finally, the membrane was connected and shaped in order to securely enclose the graft area, and the healing cap was connected and screwed onto the height connector. Outcome measures were: implant and prosthetic failure, biological and mechanical complications, marginal and volumetric bone level changes, esthetic evaluation performed according to the pink aesthetic score (PES). Results: in total, seven patients (five women, two men) with a mean age of 52.7 ± 20.3 years (range: 27–71) received 10 self-tapping tapered implants and simultaneous guided bone regeneration with ultra-fine titanium mesh membranes. No implants and no prostheses failed during the entire follow-up period. One slightly membrane exposure was observed one month after implant placement in one patient. The mean marginal bone loss (MBL) at implant loading was 0.13 ± 0.09 mm (95% CI 0.08–0.19). At the 18-month follow-up examination, the mean MBL was 0.28 ± 0.33 mm (95% CI 0.07–0.50) The difference was not statistically significant (0.15 ± 0.31; 95% CI 0.05–0.35; P = 0.1888). The mean horizontal alveolar ridge width was 3.72 ± 1.08 mm (95% CI 3.22–4.22 mm). At the II-stage surgery, the mean bone width was 8.79 ± 0.98 mm (95% CI 8.51–9.07 mm). The mean bone gain was 5.06 ± 1.13 mm (95% CI 4.68–5.44 mm; P = 0.000). The mean volume of the grafted bone calculated using the superimposition technique was 0.99 ± 0.38 CC (95% CI 0.75–1.23 CC). The mean PES at implant loading was 8.2 ± 0.8 mm (95% CI 7.7–8.7). At the 18-month follow-up examination, the mean PES was 12.0 ± 0.7 mm (95% CI 11.5–12.5) The difference was statistically significant (3.8 ± 0.4; 95% CI 3.5–4.1; P = 0.0000); Conclusion: with the limitation of the present prospective study, the guided bone reconstruction using an ultra-fine titanium mesh membrane with simultaneous implant placement seems to provide good and stable results in implant/prosthesis success. Further research with a longer follow-up and a higher sample size are needed to confirm the results from this preliminary report.

Maxillary Sinus Membrane Elevation Using a Special Drilling System and Hydraulic Pressure: A 2-Year Prospective Cohort Study

The purpose of this study was to evaluate clinical and radiologic outcomes using a newly developed device for maxillary sinus membrane elevation. Patients with a residual bone height of at least 3 mm were enrolled. Crestal sinus lift elevation and sinus graft were performed using the crestal approach sinus (CAS) kit. Graft was avoided if the residual bone crest was ≤ 2 mm less than the length of the planned implant. Outcome measures were implant and prosthesis failure, any biologic or technical complications, and marginal bone loss (MBL). A total of 35 consecutive patients underwent 49 crestal elevations of the sinus membrane. All the implants were followed for at least 2 years after placement (mean follow-up 37.3 months; range 24 to 54 months). No implants or prostheses failed during follow-up, and no membrane tears or other intraoperative or postoperative adverse events were observed. At the 2-year follow-up, mean MBL was 0.33 ± 0.24 mm (95% confidence interval: 0.08 to 0.30 mm). A total of 32 implants were placed after filling the sinus with anorganic bovine bone, while 17 implants were placed without grafting the sinus. Post-hoc analysis was performed using the sinus grafting remodeling index (SGRI) to evaluate radiographically the tissue remodeling patterns. The SGRI was statistically significantly higher when the sinus was grafted (P = .000). The CAS kit may provide a new option for minimally invasive crestal sinus surgery. Long-term randomized controlled trials with larger sample size are needed to confirm these preliminary results.

Sinus augmentation grafting with anorganic bovine bone versus 50% autologous bone mixed with 50% anorganic bovine bone: 5 years after loading results from a randomised controlled trial

PURPOSE

To compare the outcomes of implants inserted in maxillary sinuses augmented with 100% anorganic bovine bone (ABB) grafts versus mixed with 50% ABB and 50% autologous bone graft using a lateral window approach.

MATERIALS AND METHODS

This study was designed as a randomised controlled trial of parallel groups. Patients in need of an implant-supported prosthesis in maxillary posterior areas, with a residual alveolar bone height ranging between 0 and 4 mm, were recruited for lateral sinus grafting and implant placement. Patients were randomly allocated to receive two different graft materials according to a parallel group design: group A was grafted with 50% ABB and 50% autogenous bone; group B was grafted with 100% ABB. After 7 months, tapered implants were inserted with an insertion torque between 20 and 45 Ncm. Three months later implants were loaded with screw-retained temporary crowns. Definitive crowns were delivered after 3 months. Outcome measures were implant and prosthesis survival rates, complications, radiographic marginal bone-level changes, probing pocket depths (PPDs) and bleeding on probing (BOP). Clinical data were collected at definitive prosthesis delivery, and 1, 2 and 5 years after definitive loading.

RESULTS

Thirty-two consecutive patients were treated with 32 sinus elevation procedures (16 group A, 16 group B). A total of 46 implants were inserted. One patient (with two implants) dropped out in group A, and two patients (with three implants) dropped out in group B. No implant/crown failed by the end of the study. Three complications (one sinus membrane perforation and two chipping of the ceramic) were observed in three patients in group A, versus none in group B (relative risk was 0.81; 95% CI 0.64-1.03; P = 0.225). At the 2-year follow-up, the mean marginal bone loss was 1.18 ± 0.50 mm (95% CI 0.95-1.45 mm) in group A and 1.28 ± 0.48 mm (95% CI 0.97-1.43 mm) in group B, with no statistically significant differences between the two groups (difference 0.11 ± 0.22 mm; 95% CI -0.06-0.16 mm; P = 0.586). At the 5-year follow-up, the mean marginal bone loss was 1.37 ± 0.48 mm (95% CI 1.13-1.86 mm) in group A and 1.42 ± 0.48 mm (95% CI 1.17-1.90 mm) in group B (difference 0.15 ± 0.08 mm; 95% CI 0.10-0.22 mm; P = 0.426). At the 2-year follow-up, the mean PPD value was 2.70 ± 0.39 mm for group A and 2.54 ± 0.66 mm for group B, with no statistically significant difference between groups (difference 0.17 ± 0.39 mm; 95% CI 0.06-0.32 mm; P = 0.456). At the 5-year follow-up, the mean PPD value was 3.20 ± 0.44 mm for group A and 3.32 ± 0.49 mm for group B (difference 0.12 ± 0.43 mm; 95% CI 0.02-0.22 mm; P = 0.672). At the 2-year follow-up, the mean BOP value was 1.21 ± 0.79 for group A and 1.28 ± 0.68 for group B (difference 0.06 ± 0.49; 95% CI -0.23-0.25; P = 0.297), and at the 5-year follow-up, the mean BOP value was 1.77 ± 0.62 for group A and 1.91 ± 0.48 for group B (difference: 0.14 ± 0.51; 95% CI -0.05-0.33; P = 0.492).

CONCLUSIONS

Within the limitations of this study, the present data confirm similar clinical outcomes of implants inserted in sinuses grafted with ABB versus implants inserted in sinuses grafted with mixed 50% ABB and 50% autologous bone.

Accuracy of computer-assisted template-based implant placement using conventional impression and scan model or intraoral digital impression: A randomised controlled trial with 1 year of follow-up

PURPOSE

To compare accuracy and complications of computer-assisted template-based implant placement using conventional impression and scan of a physical stone cast or intraoral scanning to rehabilitate partially edentulous patients.

MATERIALS AND METHODS

Any partially edentulous patients with at least five residual teeth, requiring at least one implant to be planned on three-dimensional (3D) cone beam computed tomography (CBCT) scan according to a computer-assisted template-based protocol were enrolled. Patients were randomised according to a parallel-group design into two arms: intraoral digital impression (fully digital group) or conventional impression and scan model (conventional group). Implants were placed flapless or with a minimally invasive flap, and conventionally loaded after 5 months. Outcome measures were implant and prosthetic success, complications, accuracy and peri-implant marginal bone loss. Three deviation parameters (angular, horizontal and vertical) were defined to evaluate the discrepancy between the planned and placed implant positions. Results were compared using a mixed-model repeated-measures analysis of variance (α = 0.05).

RESULTS

Twenty patients (11 females and 9 males; mean age 44.6 years old) were randomised to the fully digital group (10 patients with 28 implants) or conventional group (10 patients with 29 implants). No patients dropped out. No implant or prosthesis failed up to 1 year after loading. One implant in the fully digital group was placed freehand due to limited inter-arch space. No biological or mechanical complications were experienced during follow-up. Difference between groups were not statistically significant (P = 0.999). The mean error in angle was 2.25 ± 1.41 degrees (range 0.30 to 5.00 degrees; 95% CI: 1.38 to 3.12 degrees) in the fully digital group and 2.10 ± 1.18 degrees (range 0.30 to 5.80 degrees; 95% CI: 1.37 to 2.83 degrees) in the conventional group. The difference was not statistically significant (-0.15 ± 1.63 degrees; range -3.20 to 2.90 degrees; 95% CI: -0.87 to 0.57 degrees; P = 0.668); in the horizontal plane (mesio-distal), the mean error was 0.52 ± 0.30 mm (range 0.10 to 1.10 mm; 95% CI: 0.33 to 0.70 mm) in the fully digital group and 0.44 ± 0.26 mm (range 0.10 to 0.90 mm; 95% CI: 0.27 to 0.60 mm) in the conventional group. The difference was not statistically significant (-0.08 ± 0.38 degrees; range -1.0 to 0.60 degrees; 95% CI: -0.32 to 0.16 degrees; P = 0.279); in the vertical plane (apico-coronal), the mean error was 0.58 ± 0.44 mm (range 0.00 to 1.60 mm; 95% CI: 0.31 to 0.85) in the fully digital group and 0.46 ± 0.34 mm (range 0.00 to 1.20 mm; 95% CI: 0.25 to 0.67) in the conventional group. The difference was not statistically significant (-0.12 ± 0.59 degrees; range -1.20 to 1.00 degrees; 95% CI: -0.49 to 0.24 degrees; P = 0.250). One year after loading, the mean marginal bone loss was 0.14 ± 0.12 mm (range -0.10 to 0.40 mm; 95% CI: 0.07 to 0.21 mm) in the fully digital group and 0.18 ± 0.13 mm (range -0.10 to 0.60 mm; 95% CI: 0.09 to 0.26 mm). The difference was not statistically significant (-0.04 ± 0.19 mm; range -0.50 to 0.30 mm; 95% CI: -0.16 to 0.08 mm; P = 0.294).

CONCLUSIONS

With the limitations of the present trial, implant rehabilitations planned using intraoral digital impressions showed similar results compared to conventional impression and scan model. Digital impression may be a viable option for the rehabilitation of partial edentulous patients when computer-guided template-assisted implant placement is used.

Classification Systems for Peri-implantitis: A Narrative Review with a Proposal of a New Evidence-Based Etiology Codification

PURPOSE

To present the different definitions of peri-implantitis proposed in the literature and to propose a new evidence-based etiology-driven classification of peri-implantitis to accurately and fully describe the etiology of peri-implantitis.

MATERIALS AND METHODS

Full-text papers on the selected topic were obtained for all abstracts and titles that appeared to meet the inclusion criteria. Additional papers were included from the reference lists of the selected studies. No methodologic and reporting quality of the included papers was applied in order to collect the greatest number of articles.

RESULTS

One hundred twenty-two studies were found according to the search criteria. After filter activation, abstract evaluation, and duplicate removal, 16 articles were deemed useful for the aim of the present narrative review. A manual search using personal contact and references of published works and contributions by the authors included another 16 articles, resulting in a total of 32 articles. After full-text article selection and reading, 15 articles were finally included.

CONCLUSION

There is not a generally accepted classification system of the various degrees of peri-implantitis. An etiology-driven classification was proposed as a tool to assist the clinician in properly detecting and classifying etiology-based peri-implantitis. This classification may also support the assignment of prognosis, and if needed, therapy to arrest/prevent peri-implantitis.

One-stage horizontal guided bone regeneration with autologous bone, anorganic bovine bone and collagen membranes: Follow-up of a prospective study 30 months after loading

PURPOSE

To present the medium-term results of one-stage guided bone regeneration (GBR) using autologous bone and anorganic bovine bone, placed in layers, in association with resorbable collagen membranes, for the reconstruction of horizontal bony defects.

MATERIALS AND METHODS

This study was designed as an uncontrolled prospective study. Partially edentulous patients, having less than 6.0 mm and more than 4.0 mm of residual horizontal bone width were selected and consecutively treated with simultaneously implant installation and bone regeneration by using 2.0 mm of autologous bone and 2.0 mm of anorganic bovine bone that was placed in layers and then covered with a resorbable collagen membrane. Outcome measures were: implant and prosthesis failures, any complications, peri-implant marginal bone level changes, probing pocket depth (PPD) and bleeding on probing (BOP).

RESULTS

In total, 45 consecutive patients (20 male, 25 female) with a mean age of 52.1 years each received at least one GBR procedure, with contemporary placement of 63 implants. At the 3-year follow-up examination, no patient had dropped out and no deviation from the original protocol had occurred. No implant or prosthesis failed. In six patients (13.3%) the collagen membrane was slightly exposed 1 to 2 weeks after bone reconstruction. Four of these patients were moderate smokers. Post-hoc analysis using Fisher's exact test found significant association (P = 0.0139) between a smoking habit and early membrane exposure. Mean marginal bone loss experienced between initial loading and 30 months afterwards was 0.60 ± 0.20 mm (95% CI 0.54 - 0.66). The mean BOP values measured at the definitive restoration delivery were 1.23 ± 0.93, while 2 years later they were 1.17 ± 0.78. The difference was not statistically significant (-0.06 ± 0.76; P = 0.569). The mean PPD values measured at the definitive restoration delivery were 2.62 ± 0.59 mm, while 2 years later they were 2.60 ± 0.54 mm. The difference was not statistically significant (-0.03 ± 0.62; P = 0.765).

CONCLUSIONS

Within the limitations of the present study, the use of a 2.0 mm layer of particulated autologous bone on the implant threads, and a 2.0 mm layer of anorganic bovine to cover the resorbed ridge, in combination with the resorbable collagen membrane, seems to be a viable treatment option for the reconstruction of horizontal bony defects.

1-year results from a split-mouth randomised controlled pilot trial comparing implants with 0.75 mm of machined collar placed at bone level or supracrestally

PURPOSE

The present study evaluated the hypothesis that implants inserted at bone level or supracrestally have different outcomes in single tooth replacements against the alternative hypothesis of no difference.

MATERIALS AND METHODS

This study was designed as a randomised, split-mouth, controlled pilot trial. Ten patients, each missing two bicuspids or molars, were treated with 20 implants featuring 0.75 mm of machined collar. Each patient randomly received one implant inserted at bone level (BL) and one inserted 0.75 mm to 1 mm above the alveolar crest (SC), measured with a periodontal probe during surgery. All the implants were inserted into healed healthy bone with an insertion torque ranging between 35 Ncm and 45 Ncm. Both implants were loaded with screw-retained acrylic-resin temporary crowns 3 months after implant insertion and 3 months later with screw-retained zirconia-ceramic definitive crowns. Outcome measures were implant/crown failures, biological and prosthetic complications, radiographic marginal bone level changes (MBL), probing pocket depth (PPD) and bleeding on probing (BOP). Clinical data were collected at baseline (implant insertion) and 1 year after implant placement (9 months after initial loading).

RESULTS

After 1 year of follow-up, no patients dropped out, no implants failed, and no complications occurred. The mean MBL at the 1-year follow-up was 0.28 ± 0.21 mm in the SC group and 0.93 ± 0.37 mm in the BL group. While the difference in MBL was statistically significant between the two treatment groups (difference 0.65 ± 0.34; 95% CI = 0.59 to 1.01; P = 0.0001), the soft-tissue parameters were not statistically different. The mean PPD was 2.63 ± 2.4 in the SC group and 2.40 ± 0.70 in the BL group (P = 0.419) and mean BOP was 0.50 ± 0.71 in the SC group and 0.40 ± 0.70 in the BL group (P = 0.754).

CONCLUSIONS

The smooth-collar implants inserted supracrestally showed 0.7 mm less radiographic marginal bone loss compared with implants inserted at the bone level 9 months after loading.

Computer-guided vs freehand placement of immediately loaded dental implants: 5-year postloading results of a randomised controlled trial

PURPOSE

To compare planning and patient rehabilitation using 3D implant planning software and dedicated surgical templates with conventional freehand implant placement for the rehabilitation of partially or fully edentulous patients using flapless or mini-flap procedures and immediate loading.

MATERIALS AND METHODS

Patients requiring at least two implants to be restored with a single prosthesis, having at least 7 mm of bone height and 4 mm in bone width were consecutively enrolled. Patients were randomised according to a parallel group study design into two groups: computerguided group or conventional freehand group. Implants were loaded immediately with a provisional prosthesis, replaced by a definitive prosthesis 4 months later. Outcome measures assessed by a blinded independent assessor were: implant and prosthesis failures, any complications, marginal bone levels, number of treatment sessions, duration of treatment, post-surgical pain and swelling, consumption of pain killers, surgical and prosthetic time, time required to solve complications, and patient satisfaction. Patients were followed up to 5 years after loading.

RESULTS

Ten patients (32 implants) were randomised to the computer-guided group and 10 patients (30 implants) were randomised to the freehand group. At the 5-year follow-up examination one patient of the computer-guided group and one of the freehand group dropped-out (both moved to another country). No prostheses failed during the entire follow-up. Two implants failed in the conventional group (6.6%) vs none in the computer-guided group (P = 0.158). Ten patients (five in each group) experienced 11 complications (six in the computer-guided group and five in the freehand group), that were successfully solved. Differences between groups for implant failures and complications were not statistically significant. Five years after loading, the mean marginal bone loss was 0.87 mm ± 0.40 (95% CI: 0.54 to 1.06 mm) in the computer-guided group and 1.29 mm ± 0.31 (95% CI: 1.09 to 1.51 mm) in the freehand group. The difference was statistically significant (difference 0.42 mm ± 0.54; 95% CI: 0.05 to 0.75; P = 0.024). Patient self-reported post-surgical pain (P = 0.037) and swelling (P = 0.007) were found to be statistically significant higher in patients in the freehand group. Number of sessions from patient's recruitment to delivery of the definitive prosthesis, number of days from the initial CBCT scan to implant placement, consumption of painkillers, averaged surgical, prosthetic, and complication times, were not statistically significant different between the groups. At the 5-year followup, all the patients were fully satisfied with the function and aesthetics of their definitive prostheses.

CONCLUSIONS

Both approaches achieved successful results over the 5-year follow-up period. Statistically higher post-operative pain and swelling were experienced at sites treated freehand with flap elevation. Less marginal bone loss (0.4 mm) was observed in the computer-guided group, at 5 years follow-up.

Immediate non-occlusal versus delayed loading of mandibular first molars. Five-year results from a randomised controlled trial

PURPOSE

To compare outcomes of immediate non-occlusal loading with delayed implant loading in the bilateral replacement of mandibular first molars.

MATERIALS AND METHODS

This study was designed as a split-mouth, randomised controlled trial. Twenty patients with bilaterally missing mandibular first molars randomly received immediately or conventionally loaded single implants. One molar was restored with a non-occlusal temporary crown within 24 hours after implant placement (immediate loading group, IL) while the contralateral molar was restored with a definitive crown 4 to 5 months later (delayed loading group, DL). A total of 40 implants were installed. All implants were inserted in healed bone with an insertion torque between 35 and 45 Ncm. Outcome measures were implant failure, complications, radiographic marginal bone level changes, probing pocket depths (PPDs) and bleeding on probing (BOP). Clinical data were collected at implant placement, and after 6, 12 and 60 months.

RESULTS

No patients dropped out and no implant failed. Only minor prosthetic complications were observed (two provisional acrylic crown fractures in the IL group and four ceramic chipping in the DL group). Two patients had bilateral peri-implant mucosal inflammation with BOP after 6 months. The differences between groups were not statistically significant (OR = 0.500; 95% CI: 0.045 to 3.489; P = 0.6831). At the 1-year follow-up examination, the mean marginal bone level was 0.83 ± 0.16 mm (95% CI: 0.75 to 0.91) in the IL group and 0.86 ± 0.16 mm (95% CI: 0.78 to 0.94) in the DL group, with no statistically significant differences between groups (difference = 0.03 ± 0.15 mm; 95% CI: -0.07 to 0.07; P = 0.53). After 5 years, mean marginal bone level was 1.06 ± 0.38 mm (95% CI: 0.97 to 1.15) in the IL group and 1.07 ± 0.32 mm (95% CI: 0.95 to 1.16) in the DL group, with no statistically significant differences between groups (difference = 0.01 ± 0.22 mm; 95% CI: -0.10 to 0.10; P = 0.96). The mean marginal bone loss after 5 years was 0.62 ± 0.45 mm in the IL group and 0.69 ± 0.33 mm in the DL group (difference = 0.07 ± 0.32 mm; 95% CI: -0.10 to 0.18; P = 0.567). At the 5-year follow-up the mean PPD and BOP values were 2.82 ± 0.65 mm and 1.17 ± 0.92 in the IL group, and 2.85 ± 0.53 mm and 1.17 ± 0.86 in the DL group, respectively. No significant differences were found (difference = 0.03 ± 0.15 mm; 95% CI: -0.15 to 0.21; P = 0.990; and 0.01 ± 0.07; 95% CI: -0.06 to 0.08; P = 1.000, respectively).

CONCLUSIONS

Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of immediate versus delayed loading of implants in mandibular fist molar sites is comparable.

Minimally Invasive Sinus Augmentation Procedure Using a Dedicated Hydraulic Sinus Lift Implant Device: A Prospective Case Series Study on Clinical, Radiologic, and Patient-Centered Outcomes

The aim of this study was to evaluate clinical and radiologic outcomes of a novel device that allows simultaneous hydraulic sinus membrane elevation, bone grafting, and implant placement. A sample of 18 consecutive participants with severe atrophy of the posterior maxilla underwent transcrestal elevation of the sinus membrane and implant placement. At the 6-month follow-up, the following parameters were assessed: implant success, any complications, marginal bone loss (MBL), three-dimensional (3D) graft measurements, implant stability quotient (ISQ), and graft density. No implants failed during follow-up (10.8 ± 2.8 months; range: 7-14 months). No membrane tears or other adverse events were observed. Mean residual alveolar ridge height was 4.78 ± 0.88 mm. Six months after the procedure, the mean MBL was 0.18 mm. The mean sinus membrane elevation was 12.78 ± 2.18 mm (range: 10.7-14.23). Along the basic 3D reference planes, the dimensions of grafted bone measured around implants were as follows: axial area = 239.7 ± 57.68 mm²; sagittal area = 257.0 ± 60.83 mm²; coronal area = 143.3 ± 29.46 mm². The mean volume of the graft was 2.38 ± 0.26 mL at baseline and 2.05 ± 0.24 mL 6 months after graft maturation (difference: 0.33 ± 0.29 mL, P = .0090). Graft density (in Hounsfield units [HU]), improved during healing from 322.0 ± 100.42 HU to 1,062.0 ± 293.7 HU; difference 740.0 ± 295.35 HU (P = .0001). The mean ISQ value was 65.5 at implant placement, and it increased to 74.1 at the 6-month examination (P = .0014). Of 18 patients, 12 experienced no pain (66.6%) and 10 experienced no swelling (55.5%). No severe pain or swelling was reported in any of the cases. The mean number of analgesic tablets consumed was 0.78 ± 0.67. Mean surgical time was 24.0 ± 4.07 minutes. The iRaise Sinus Lift System may provide a new option for minimally invasive transcrestal sinus surgery with minimal patient discomfort. A physiologic contraction of 13.9% of its original volume was experienced during healing. Long-term clinical studies are needed to confirm these preliminary results.

Definitive Abutments Placed at Implant Insertion and Never Removed: Is It an Effective Approach? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

To assess whether repeated abutment disconnections and reconnections have any impact on peri-implant bone resorption and soft tissue healing.

MATERIALS AND METHODS

Electronic and manual searches were conducted for English-language articles published up to March 2017 that identified a relation between repeated disconnections of implant abutments (PA group) and prosthetic or implant failures, complications, marginal bone loss (MBL), soft tissue healing, and esthetic evaluation (pink esthetic score [PES]) after at least 1 year of function compared with implants receiving a final abutment at the time of implant placement (DA group).

RESULTS

Fourteen articles (535 patients with 994 implants) were selected for qualitative analysis. Six of these were included in the meta-analysis. Five prostheses failed in the PA group and 1 failed in the DA group (P = .1047). Seven biologic complications occurred in the PA group and 6 occurred in the DA group (P = .8121). MBL was significantly less in the DA group (difference, 0.279 mm; P = .000). Greater buccal recession occurred in the PA group (difference, 0.198 mm; P = .0004). The PES evaluation showed no differences between groups (P = .289).

CONCLUSIONS

Repeated abutment disconnections and reconnections considerably increased MBL and buccal recession. Further studies are needed to confirm these results.

Mucosa Thickness and Peri-implant Crestal Bone Stability: A Clinical and Histologic Prospective Cohort Trial

PURPOSE

To correlate soft tissue thickness and peri-implant bone remodeling of platform-switching implants.

MATERIALS AND METHODS

This comparative prospective trial evaluated, for up to 3 years after implant loading, the influence of soft tissue thickness on changes in peri-implant marginal hard tissue levels. Any patient who was partially edentate in the mandible and required at least two adjacent implant-supported restorations was recruited at the University of Valencia in Spain. A 3-mm tissue punch biopsy, which corresponded to a diameter slightly smaller than the coronal diameter of the implants, was performed using a circular mucotome. Afterward, implants with a length of 10 to 13 mm and a diameter of 3.8 mm were inserted. Outcome measures were implant and prosthesis survival rates, marginal hard tissue changes, any complications, and results of morphologic and histomorphometric analyses. Correlation between mucosa width components (epithelium, connective tissue, and epithelium and connective tissue) and radiographic bone loss at 1 and 3 years after loading was performed at the patient level. Statistical significance was set at P ≤ .05.

RESULTS

A total of 26 samples in 26 patients with 68 implants were analyzed. The specimens were divided into two groups: group 1 (16 patients, 40 implants), with thin mucosa (≤ 2 mm), and group 2 (10 patients, 28 implants), with thick mucosa (> 2 mm). Two dropouts (two specimens) were recorded at the 3-year follow-up. None of the implants or definitive prostheses failed during the healing period, resulting in an overall implant and prosthesis cumulative survival rate of 100%. No major biologic or mechanical complications were recorded. The mean (standard deviation, SD) epithelium thickness was 430.33 (250.21) μm; the mean (SD) connective tissue thickness was 1,324.31 (653.46) μm, and the mean (SD) mucosa thickness was 1,751.29 (759.53) μm. Comparisons of radiographic bone loss between group 1 and group 2 failed to show any statistically significant differences at the 1-year (P = .290) or 3-year (P = .090) follow-up examinations.

CONCLUSION

The initial mucosa thickness surrounding a bone-level platform-switching implant seems not to influence the pattern of physiologic marginal bone loss.

Vertiginous crisis following temporomandibular joint athrocentesis: a case report

Temporomandibular joint arthrocentesis and arthroscopy have recently exceeded open surgeries for disorders that failed to respond to conservative treatment. The efficacy of arthrocentesis in reestablishing normal mouth opening and reducing pain and dysfunctions is now commonly accepted, but in contrast to arthroscopy, there are no large series studies on arthrocentesis complications. We report the major complication occurred in our experience: a case of a patient that complained of a violent vertigo, without hearing disorders, following the procedure.

Aesthetic and Functional Evaluation of Total Nasal Reconstructions

The loss of a portion or the totality of the nose has great relevance on the perception of the beauty of a face and can result in a catastrophic quality of life impairment. Several surgical techniques are currently available for the reconstruction of the nasal pyramid. However, there are very few nasal reconstruction quality evaluation protocols that allow the surgeon to choose objectively the best technique for each kind of defects. Six total nasal reconstruction performed in University of Sassari Maxillofacial Unit were evaluated with a protocol that investigate objectively and subjectively the surgical aesthetic and functional outcome. Sensitivity recovery on the reconstructive flaps was also assessed. Patients reported a satisfactory nasal reconstruction both functionally and aesthetically. Sensitivity recovery on the forehead flap was always present even after pedicle resection or in case of traumatic section of the infraorbital nerve. The use of a three layer reconstruction has proved a viable technique both aesthetically and functionally. In particular the use of the forehead flap to reconstruct the outer layer of the nose allows to carry a tissue with very similar characteristics to the original with a recovery of the sensitivity almost complete.

Crestal sinus lift using an implant with an internal L-shaped channel: 1-year after loading results from a prospective cohort study

PURPOSE

To evaluate the clinical and radiographic outcomes of a one-stage crestal sinus elevation procedure using a self-tapping endosseous implant system (iRaise, Maxillent, Herzliya, Israel) developed for sinus augmentation, 1 year after loading.

MATERIALS AND METHODS

Patients needing restoration in the posterior maxilla with a residual alveolar crest of 3 to 8 mm in height and 5 mm in width distal to the canine as measured on CBCT scan were treated using the iRaise sinus lift system. Outcome measures were: implant and prosthetic failures, any complications, increased bone height (iBH), marginal bone loss (MBL), implant stability quotient (ISQ), radiographic tissue remodelling patterns using the sinus grafting remodelling index (SGRI), volumetric measurements of sinus graft, patient self-reported post-surgical swelling, consumption of pain medication and histological analysis.

RESULTS

A total of 30 consecutive participants with a mean age of 54.2 ± 9.4 years underwent a transcrestal elevation of the sinus membrane, insertion of bone graft, and implant placement. A total of 50 implants were placed (30 iRaise system implants and 20 adjunctive iSure implants, Maxillent). The mean follow-up was 15.8 ± 2.1 months after implant loading. One patient dropped out at the 1-year after loading follow-up examination. No implants and no prostheses failed during the entire follow-up. One patient experienced a small membrane tear. Before implant insertion, the mean residual alveolar ridge height was 4.64 ± 0.86 mm (range: 3.4-6.4 mm; 95% CI: 4.39-5.01 mm). One year after loading, the bone height was 16.86 ± 3.13 mm (95% CI 15.83-18.07 mm). At the 1-year after loading follow-up, the mean MBL was 0.19 ± 1.05 mm (95% CI 0.02-0.78 mm). The mean ISQ at implant placement was 65.2 ± 5.4 (95% CI 63.6-67.4) and increased during the healing period reaching the mean value of 73.6 ± 3.7 (95% CI 73.1-75.9; range 62-79). The difference was statistically significant (8.4 ± 5.3; 95% CI 5.9-39.7; P = 0.0000). One year after loading, SGRI score was evaluated in 23 implants. Overall, the mean SGRI value was 2.29 ± 2.41 mm (95% CI 1.22-2.98 mm). Bone volume at implant placement was 2.41 ± 0.25 CC (95% CI 2.22-2.48 CC). During the 6-month, submerged healing period, a slight bone contraction of 11.3% were observed. (2.13 ± 0.24 CC;95% CI 2.02-2.26; difference = 0.27 ± 0.25 CC; 95% CI 0.10-0.36; P = 0.0011). At the first year post-loading period, the bone graft remained stable (2.11 ± 0.22 CC; 95% CI 2.02-2.24). The difference was not statistically significant (0.02 ± 0.07 CC; 95% CI 0.01-0.04; P = 0.2166). From the patient's point of view, the mean pain value was 0.52 ± 0.74 (range 0-3); mean swelling value was 0.27 ± 0.52 (range 0-2); and the mean consumption of analgesic was 0.87 ± 4.94 tablets (range 0-4) 3 days after surgery. Morphological and histomorphometric analyses showed that all the samples had a normal structure without inflammatory infiltrate, six months after healing. The following fractions (%) were found: bone (immature bone + mature bone): 44.07 ± 4.91; residual biomaterial: 23.98 ± 2.64; medullary spaces: 31.95 ± 3.16.

CONCLUSIONS

Sinus floor augmentation can be successfully accomplished with a transcrestal approach using a dedicated implant system. A physiologic contraction of 11.3% of the original volume of the bone graft was experienced during the first 6 months of healing; afterwards, no additional graft volume reduction was observed. Long-term clinical studies are needed to confirm these preliminary results.

Molar replacement with 7 mm-wide diameter implants: to place the implant immediately or to wait 4 months after socket preservation? 1 year after loading results from a randomised controlled trial

PURPOSE

To test the hypothesis that there is no difference in clinical, radiographic and aesthetic outcomes positioning single post-extractive 7 mm-diameter implants or waiting 4 months after molar extraction and socket preservation procedure.

MATERIAL AND METHODS

Patients requiring one implant-supported single restoration to replace a failing tooth in the molar region of both maxilla and mandible were selected. Patients were randomised according to a parallel group design into two arms: implant installation in fresh extraction sockets grafted with cortico-cancellous heterologous bone and porcine derma (group A) or delayed implant installation 4 months after tooth extraction and socket preservation using the same materials (group B). Implants were submerged for 4 months. The primary outcome measures were the success rates of the implants and prostheses and the occurrence of any surgical and prosthetic complications during the entire follow-up. Secondary outcome measures were: peri-implant marginal bone level (MBL) changes, resonance frequency analysis (ISQ) and pink esthetic score (PES) values at implant placement (baseline) up to 1 year after loading.

RESULTS

Twelve patients were randomised to group A and 12 to group B. No patient dropped out within 1 year after loading. No implant and prosthesis failed and no complications occurred during the entire follow-up. One year after loading, statistically significant higher mean MBL loss was experienced in group A (0.63 mm ± 0.31 mm) compared to group B (0.23 mm ± 0.06 mm); difference 0.41 mm (95% CI 0.17-0.53; P = 0.001). Six months after implant placement, mean ISQ value was 78.8 ± 2.8 for group A and 79.9 ± 3.6 for group B, showing no statistically significant difference between groups (difference 1.1; 95% CI: 0.04 to 2.96; P = 0.422). One year after loading, mean PES was 10.6 ± 1.8 [range: 8 to13] in group A and 12.2 ± 1.2 [range: 11 to 14] in group B. The difference was statistically significant (1.6 ± 2.7; 95% CI -0.55-2.55; P = 0.019) with better results for group B.

CONCLUSIONS

Within the limitations of this study, both procedures achieved successful results over the 1-year follow-up period, but waiting 4 months after tooth extraction and socket preservation procedure was associated with less marginal bone loss and a better aesthetic outcome. Conflict-of-interest statement: Dr Marco Tallarico is Research Project Manager of Osstem AIC Italy. However no company supported this study and all authors declare no conflicts of interest.

Sinus lift grafting with anorganic bovine bone vs 50% autologous bone mixed with 50% anorganic bovine bone: 2 years after loading results from a randomised controlled trial

PURPOSE

To compare the outcome of implants inserted in maxillary sinuses augmented with anorganic bovine bone (ABB) grafts vs mixed 50% ABB and 50% autologous bone graft, using a lateral window approach.

MATERIALS AND METHODS

This study was designed as a randomised controlled trial of parallel groups. Patients in need of an implant-supported prosthesis in a maxillary posterior area with a residual alveolar bone height no greater than 4 mm (range 0-4 mm) were recruited for lateral sinus grafting. Patients were randomly allocated to receive 50% ABB and 50% autogenous bone (group A) or 100% ABB (group B). After 7 months, tapered implants were inserted with an insertion torque between 20 and 45 Ncm. After 3 months, implants were loaded with screw-retained temporary crowns. Definitive crowns were delivered 3 months later. Outcome measures were implant survival, complications, radiographic marginal bone-level changes, probing pocket depths (PPD) and bleeding on probing (BOP). Clinical data were collected at definitive prosthesis delivery, 1 and 2 years after loading.

RESULTS

Thirty-two consecutive patients were treated with 32 sinus lift procedures (16 group A, 16 group B). A total of 46 implants were installed. No patient dropped out. No crown/implant failed by the end of the study. Three complications (one sinus membrane perforation and two chipping of the ceramic) were observed in three patients in group A, vs none in group B (RR 0.81; 95% CI 0.64 - 1.03 mm; P = 0.225). At the 2-year after final loading follow-up, the mean marginal bone loss was 1.18 ± 0.50 mm (95% CI 0.95 - 1.45 mm) in group A and 1.28 ± 0.48 mm (95% CI 0.97 - 1.43 mm) in group B, with no statistically significant differences between the two groups (difference 0.11 ± 0.22 mm; 95% CI -0.06 - 0.16 mm; P = 0.586). At the same follow-up, the mean PPD value was 2.70 ± 0.39 for group A and 2.54 ± 0.66 for group B, with no statistically significant difference between groups (difference 0.17 ± 0.39 mm; 95% CI 0.06 - 0.32 mm; P = 0.456), while the mean BOP value was 1.21 ± 0.79 for group A and 1.28 ± 0.68 for group B, (difference: 0.06 ± 0.49 mm; 95% CI -0.23 - 0.25 mm; P = 0.297).

CONCLUSIONS

Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of implants inserted in sinuses grafted with ABB vs implants inserted in sinuses grafted with mixed 50% ABB and 50% autologous bone are comparable. Conflict-of-interest statement: This study was not supported by any company. All the authors declare no conflict of interest.

A novel implant system dedicate to hydraulic Schneiderian membrane elevation and simultaneously bone graft augmentation: An up-to 45 months retrospective clinical study

PURPOSE

To evaluate clinical and radiographic performance of a novel implant system that allows for hydraulic Schneiderian membrane elevation and simultaneously bone graft augmentation.

MATERIALS AND METHODS

Sixty-two consecutive patients with a mean age of 53.1 years and a severe atrophy of the posterior maxilla (3.0 to 7.0 mm) underwent 64 transcrestal sinus floor elevations and submerged implant placement. The following clinical and radiographic parameters were assessed: implant failure, any complications and bone gain measured using cone beam computed tomography.

RESULTS

No patient dropped out. No implants failed and all the prostheses were uneventful at the last follow-up examination (mean 23.0 months; range 12-45). All the procedures were completed successfully, with elevation of the sinus membrane and insertion of bone graft and the dental implant at the planned site. No intraoperative or postoperative adverse events were observed, such as membrane tears or facial hematoma. The mean residual alveolar ridge height was 5.2 ± 1 mm (range 3.3-7.0 mm). Mean bone gain was 10.9 ± 2.43 mm (range 5.3-16.5) after an average healing period of 8 months.

CONCLUSIONS

Hydraulic elevation of the Schneiderian membrane using the iRaise sinus-lift system (Maxillent Ltd) can be considered a valuable treatment option for the rehabilitation of atrophic edentulous posterior maxillae.

Single post-extractive ultra-wide 7 mm-diameter implants versus implants placed in molar healed sites after socket preservation for molar replacement: 6-month post-loading results from a randomised controlled trial

PURPOSE

To test the hypothesis that there is no difference in clinical, radiographic and aesthetic outcomes positioning single post-extractive ultra-wide 7 mm-diameter implants or waiting 4 months to place implant, after molar extraction and the socket preservation procedure.

MATERIAL AND METHODS

Patients requiring one implant-supported single restoration to replace a failed tooth in the molar region of both maxilla and mandible were selected. Patients were randomised according to a parallel group design into two arms: implant installation in fresh extraction sockets augmented with corticocancellous heterologous bone and porcine derma (group A) or delayed implant installation 4 months after tooth extraction and socket preservation using the same materials (group B). Ultra-wide 7 mm-diameter implants were submerged for 4 months. Outcome measures were implant success and survival; complications; horizontal dimensional changes measured on cone beam computed tomography (CBCT) scans at three levels, localised 1, 2 and 3 mm below the most coronal aspect of the bone crest (level A, B and C); peri-implant marginal bone level changes; implant stability quotient (ISQ); and pink esthetic score (PES).

RESULTS

Twelve patients were randomised to group A and 12 to group B. No patients dropped out. No implant failed or complications occurred up to 6-months post-loading. Six months after loading there was more horizontal alveolar bone reduction at immediate post-extractive implants, which was statistically significant. At level A was 1.78 mm ± 1.30 in group A, 0.45 mm ± 0.42 in group B, (difference 1.33 mm ± 1.39; 95% CI: 0.38 to 1.95; P = 0.003); at level B was 0.98 mm ± 1.13 in group A, 0.14 mm ± 0.22 in group B, (difference 0.84 mm ± 1.16; 95% CI: 0.24 to 1.07; P = 0.019); at level C was 0.55 mm ± 0.74 in group A, 0.03 mm ± 0.24 in group B, (difference 0.51 mm ± 0.76, 95% CI: 0.01 to 0.87; P = 0.032). One year after implant placement, mean peri-implant marginal bone loss was 0.43 mm ± 0.37 for group A and 0.10 mm ± 0.10 for group B, showing a statistically significant difference between groups (difference 0.33 mm ± 0.30; 95% CI: 18 to 0.52; P = 0.010). Mean ISQ value was 78.8 ± 2.8 for group A and 79.9 ± 3.6 for group B, showing no statistically significant differences between groups (difference 1.1 ± 2.6; 95% CI: 0.04 to 2.96; P = 0.422). Mean PES was similar in both groups (10.7 ± 1.5 [range: 8 to 13] in group A and 11.7 ± 1.2 [range: 10 to 13] in group B; difference 1.0 ± 2.2; 95% CI: -0.23 to 2.23; P = 0.081).

CONCLUSIONS

Single post-extractive ultra-wide 7 mm-diameter implants, in combination with socket preservation, might be a possible strategy in the replacement of hopeless molars in both jaws, with high implant and prosthetic survival and success rates, and good aesthetic outcomes. Longer follow-ups are needed to properly evaluate this therapeutic option. Conflict-of-interest statement: Dr Marco Tallarico is Research and Scientific Project Manager of Osstem AIC Italy. However, this study was not supported by any company and all authors declare no conflicts of interest.

Platform switching versus regular platform implants: 3-year post-loading results from a randomised controlled trial

PURPOSE

To test the hypothesis that platform switching and regular platform implants would have different outcomes in single-tooth replacement against the alternative hypothesis of no difference.

MATERIAL AND METHODS

This study was designed as a randomised controlled split-mouth trial. Eighteen patients with bilaterally missing single premolars or molars to be restored with implant-supported single crowns, were consecutively enrolled. Implant sites were randomly assigned to be treated according to the platform switching concept (PS group), or with matching implant-abutment diameters (RP group). A total of 36 Nobel Replace Tapered Groovy implants were installed. All the implants were inserted in healed bone, with an insertion torque between 35 and 45 Ncm, according to a one-stage protocol. Both implant types were loaded with a screw-retained temporary crown 3 months after implant insertion. Definitive screw-retained single crowns were delivered 2 months later. Outcome measures were implant and prosthetic survival rates, biological and prosthetic complications, radiographic marginal bone level (MBL) changes, pocket probing depth (PPD) and bleeding on probing (BOP). Clinical data was collected at implant placement (baseline), and at 3, 9 and 36 months after loading.

RESULTS

No patients dropped out and no implant failed. No prosthetic complications were recorded. One patient experienced mucosal inflammation with positive BOP (RP group) after 3 months, three patients had bilateral peri-implant mucosal inflammation with positive BOP at 6, 24 and 30 months after loading, respectively. There were no statistically significant differences between groups for complications (3/18 versus 4/18; P = 1.0; Odds Ratio = 1.333; 95% CI: 0.3467 to 5.1272). Nine months after loading, the mean MBL was 0.93 ± 0.26 mm in the RP group and 0.84 ± 0.23 mm in the PS group, with no statistically significant differences between groups (mean difference = 0.09 mm, 95% CI: -0.22 to 0.04, P = 0.18). Three years after loading, mean MBL was 1.09 ± 0.31 mm in the RP group and 1.06 ± 0.24 mm in the PS group, with no statistically significant differences between groups (mean difference = 0.02 mm, 95% CI: -0.06 to 0.10, P = 0.70). Marginal bone level changes between 3 years and baseline were 0.72 ± 0.28 mm in the RP group and 0.71 ± 0.27 mm in the PS group, with no statistically significant differences between the groups (mean difference = -0.00 mm, 95% CI: -0.07 to 0.07, P = 0.89). Mean PPD was 2.70 ± 0.52 mm in the RP group and 2.46 ± 0.69 mm in the PS group at 36 months after loading, with no statistically significant differences between the groups (mean difference = 0.23 mm, 95% CI: -0.05 to 0.35, P = 0.43). Mean BOP was 0.83 ± 0.96 mm in the RP group and 0.89 ± 0.99 mm in the PS group at 36 months after loading, with no statistically significant differences between the groups (mean difference = 0.07 mm, 95% CI: -0.03 to 0.17, P = 0.77).
 Conclusions: The clinical and radiographic outcomes of implants restored according to the platform-switching concept versus implants restored with the matching implant-abutment diameters are comparable, 3 years after loading. Conflict of interest statement: This study was not supported by any company. All authors declare no conflict of interest.