International Journal of Oral Implantology, 02/2022

Purpose: To evaluate the short- and long-term outcomes of vertical 3D bone augmentation in the posterior mandible, performed using the split bone block technique with a tunnel technique. Materials and methods: Patients were treated for vertical and horizontal alveolar bone defects without simultaneous implant placement and followed up for at least 10 years postoperatively. Autogenous bone blocks were harvested from the mandibular retromolar area following the MicroSaw protocol (Dentsply Sirona, Charlotte, NC, USA). The harvested bone blocks were split longitudinally according to the split bone block technique and grafted in 3D form using a tunnel technique. Implants were inserted and exposed after 3 months and prosthetic restoration was performed. Results: A total of 117 consecutively treated patients with 128 grafted sites in 3D form were enrolled in the present study and followed up over a period of up to 17 years. The 10-year results were collected with a total patient dropout rate of 24.13%. Minimal late graft exposure was documented postoperatively for 4 to 8 weeks on the lingual site in two cases but did not influence the outcome. Infection of the grafted area occurred in one other case, leading to loss of the grafted bone. The postoperative mean vertical bone gain was 7.6 ± 3.1 mm and the mean bone width achieved after surgery was 8.1 ± 1.6 mm. A total of 287 implants were inserted 3 months after the augmentation procedure. The maximum vertical bone resorption, which was calculated around implants, was 0.66 ± 0.38 mm after 1 year, 0.72 ± 0.31 mm after 5 years and 0.75 ± 0.43 mm after 10 years. Furthermore, five implants were lost during this time, due to peri-implantitis and chronic pain. After 10 years, the mean vertical bone gain was stable at 6.72 ± 2.26 mm and the resorption rate was 11.4%. Conclusions: The short- and long-term results of the present study confirm the predictability of using mandibular bone blocks according to the split bone block technique for 3D bone reconstruction in the posterior mandible. Keywords: 3D bone augmentation, MicroSaw protocol, posterior mandible, split bone block technique, tunnel technique, vertical alveolar crest augmentation Conflict-of-interest statement: This study was completely self-supported and no contribution from any commercial party was received, even in the form of free materials.

Purpose: To evaluate the clinical, radiographic and patient-related outcomes of a novel technique for digitalisation and customisation of reinforced polytetrafluoroethylene meshes in vertical ridge augmentation surgery. Materials and methods: A total of 10 patients (five men and five women, mean age 54 years) with vertical defects were included in the study. Prior to surgery, digital planning of bone augmentation, manufacturing of 3D printed models and replicas of the meshes and modelling of a customised reinforced polytetrafluoroethylene mesh were carried out. All patients were treated using a 50:50 mixture of xenogeneic and autogenous bone, customised reinforced polytetrafluoroethylene mesh and collagen membrane. After 6 to 9 months, computer-guided surgery was planned, the reinforced polytetrafluoroethylene mesh was removed and implants were placed in augmented sites using a fully guided surgical template. Patient-related outcomes, intraoperative timing, surgical and healing complications, vertical bone gain, bone density, pseudoperiosteum type and number and stability of implants were recorded. Results: All 10 patients were treated without surgical complications. Healing was largely uneventful, with the exception of one case of abscess formation without mesh exposure (exposure rate 0%). The mean duration of digital planning was 17.0 minutes, reinforced polytetrafluoroethylene mesh customisation took 9.0 minutes, and the total intraoperative time was 91.3 minutes. The mean planned bone volume was 1.52 cc, vertical bone defect depth was 6.0 ± 1.7 mm and vertical bone gain was 5.5 ± 1.9 mm; most sites showed medium bone density and a Type 1 pseudoperiosteum. All patient-related outcomes were favourable. Conclusions: The preliminary results of this pilot study demonstrated the feasibility and reliability of a fully digital workflow for the customisation of reinforced polytetrafluoroethylene mesh in vertical ridge augmentation. Keywords: 3D printing, alveolar bone atrophy, dental implants, guided bone regeneration, guided implant surgery Conflict-of-interest statement: The authors report no conflicts of interest relating to this study.

Purpose: To evaluate the in vitro cleaning effects of different decontamination methods and their impacts on surface characteristics using clinically failed TiUnite implants (Nobel Biocare, Kloten, Switzerland). Materials and methods: Thirty clinically failed TiUnite implants were treated using different decontamination methods. Group 1 (control group) received physiological saline irrigation; Group 2 underwent erythritol powder air polishing (AIRFLOW Master Piezon, EMS Dental, Nyon, Switzerland); Group 3 was treated with erythritol powder air polishing with ethylenediaminetetraacetic acid brushing (FileRite PRC, Pulpdent, Watertown, MA, USA); Group 4 received ultrasonic scaling with polyetheretherketone tips (EMS Dental); Group 5 underwent ultrasonic scaling with polyetheretherketone tips with ethylenediaminetetraacetic acid; and Group 6 was treated with a combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic acid. Surface cleaning effects, quantified by relative contaminated area reduction and visual analogue scale score, as well as surface roughness and chemistry, were assessed after decontamination. The cleaning effects of each decontamination method were also compared between TiUnite and SLA (sandblasted, large-grit acid-etched; Straumann, Basel, Switzerland) implants. Results: Group 6 showed the highest relative contaminated area reduction (stereoscopic microscopy 83.92%, scanning electron microscopy 96.40%), visual analogue scale score (2.83) and reduction in surface roughness (thread bottom −0.78 μm, tip −1.35 μm), as well as an almost maximal decrease in the proportion of carbon (thread bottom −12.33%, tip −8.77%) and increase in that of titanium (thread bottom 13.71%, tip 10.73%). Polyetheretherketone remnants were observed in Groups 4 and 5 but appeared to be reduced in Group 6. When comparing the outcomes with those for SLA implants, no significant differences were found. Conclusion: Within the limitations of the present study, the combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic brushing achieved reasonable cleaning effects. The original surface modification did not seem to have any impact on the decontamination results for any of the methods examined. Keywords: air polishing, decontamination methods, ethylenediaminetetraacetic acid, implant surface, peri-implantitis Conflict-of-interest statement: The authors declare there are no conflicts of interest relating to this study.

Purpose: Titanium bases are used frequently in daily practice for bonding to CAD/CAM abutments or crowns. Due to intimate contact between the adhesive gap of the titanium-base abutment and the peri-implant bone, the physical and chemical characteristics of the bonding material, or the gap itself, may affect peri-implant inflammatory reactions. The present study therefore aimed to examine the long-term effects of individualised abutments bonded to titanium bases on peri-implant health. Materials and methods: A total of 24 patients, each with one test and one control abutment, participated in the present prospective, single-blind, randomised controlled clinical trial. The test abutments were CAD/CAM titanium abutments bonded to titanium bases. As the control abutments were individualised, one-piece CAD/CAM titanium abutments were used. Clinical and radiographic parameters were assessed at abutment insertion and then on a yearly basis over the following 5 years. Results: No significant differences in marginal bone level were observed between the titanium-base and one-piece abutments at any of the follow-up time points; however, when intragroup marginal bone levels were compared to the baseline values, significant differences were found at several follow-up time points. Intergroup differences were only found to be significant for pocket depth at the 4- (P = 0.006) and 5-year follow-ups (P = 0.024), favouring titanium-base abutments. Conclusions: Within the limitations of the present study, it appears that the peri-implant tissues of this specific patient cohort responded to titanium-base abutments in a rather similar manner to one-piece abutments over a 5-year period; however, no definitive conclusions can be drawn due to the low power of the present study. Keywords: abutment, dental implant, peri-implant bone loss, titanium-base abutment Conflict-of-interest statement: The authors declare there are no conflicts of interest relating to this study.

Aims: Zygomatic implants are successful alternatives to conventional dental implants for oral rehabilitation of patients with severely atrophic maxillae; however, the use of unilateral zygomatic implants needs to be studied further to validate their efficacy. The present investigation aimed to evaluate unilateral zygomatic implant placement in the oral rehabilitation of partially edentulous patients with extremely atrophic maxillary bone and/or previous implant failures. Materials and methods: This retrospective clinical study included patients with partially edentulous maxillae who underwent unilateral zygomatic implant insertion. The primary outcome was implant survival. Intraoperative, postoperative and prosthetic complications were also assessed based on patients’ clinical records. Results: A total of 32 patients (34 zygomatic implants) with a mean age of 60.45 ± 8.74 years (range 47 to 78 years) were included in the study. The mean follow-up period was 34.3 ± 25.5 months, and the overall implant survival rate was 100%. No intraoperative or postoperative complications developed in any of the patients, and no prosthesis failures or complications were recorded. Conclusions: The results indicate that unilateral zygomatic implant insertion for oral rehabilitation of patients with partially edentulous posterior maxillae with severely atrophic bone and/or previous implant failures can be considered a successful alternative to use of conventional dental implants associated with advanced bone grafting procedures. Keywords: maxillary rehabilitation, oral rehabilitation, partially edentulous atrophic maxilla, unilateral zygomatic implants, zygomatic implants Conflict-of-interest statement: The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article.