Vascular and neurosensory evaluation in relation to lingual canal anatomy after mandibular midline implant installation in edentulous patients

Objectives The aim of this study is to investigate vascular and neurosensory complications in edentulous patients following the installation of mandibular midline single implants in relation to lingual canals. Materials and methods After performing a cone beam computed tomography scan for the 50 recruited patients, the relationship between the potential implant site and the lingual canals was assessed, and all vascular and neurosensory complications were recorded. Results Six patients (12%) reported profuse bleeding during implant placement, and 13 (26%) reported transient neurosensory changes, which were resolved after 3 months. According to the virtual implant planning, 44 patients (88%) would have their implants touching the lingual canals, six of them reported vascular changes (14%), and 12 out of 44 patients reported neurosensory changes (27%). For the six patients who would have their implants not touching the lingual canals, one patient reported transient neurosensory changes. Conclusions The mandibular lingual canals are constant anatomic landmarks. Injury to the supra-spinosum lingual canals may occur during midline implant placement, depending on the implant length and the bone height. Clinical relevance Despite that injury to the supra-spinosum lingual canals during implant insertion does not result in permanent vascular or neurosensory complications, caution is required to avoid the perforation of the lingual cortices.

Osteotome-Induced Blood Clot and Subsequent Bone Formation with the Use of Collagen Sponge for Integration of Single Dental Implants into the Atrophied Posterior Maxilla: A Retrospective Follow-Up of 36 Implants after 5 to 13 years

Background. Atrophy of the posterior maxilla as a consequence of tooth loss and sinus pneumatization is a frequent condition encountered in the clinical practice. Prosthetic rehabilitation with implants in these patients often requires some kind of bone regeneration procedure to increase the bone volume. Aim. The aim of the present retrospective study is to analyze the survival and success rates of a series of implants placed in the atrophic posterior maxilla with a transcrestal osteotome procedure, without placing a bone grafting material. Materials and Methods. From 2006 to 2014, 36 dental implants (Neoss Ltd., Harrogate, UK) were inserted in 36 patients with at least 4 mm of bone below the maxillary sinus using transcrestal osteotome sinus floor elevation and placement of collagen sponge below the sinus membrane. ISQ measurements were made after implant placement and at abutment surgery after 4 to 6 months. The vertical bone height (VBH) was evaluated in intraoral radiographs taken prior to surgery and in radiographs from annual check-up appointments 5 to 13 years after implant placement. In addition, marginal bone loss (MBL) was evaluated. Results. One implant was lost after four years of prosthetic loading. The remaining 35 implants showed no complications and were loaded with single crowns after 4–6 months of healing. All 35 implants showed clinical success after 8.5 ± 2.8 years of prosthetic loading (from 5 to 13 years). The vertical bone height was 5.9 ± 1.4 mm at surgery, 9.7 ± 1.1 mm at second surgery after 4–6 months, and 8.3 ± 1.8 at the follow-up at 8.5 ± 2.8 years (from 5 to 13 years). The implant stability registered was 73.2 ± 6.2 ISQ at the surgery and 75.8 ± 3.9 at the second surgery after 4–6 months. Conclusions. The present long-term follow-up study showed that the crestal approach for sinus floor bone augmentation without additional bone grafting results in predicable bone formation and high implant survival. The osteotome technique is a valid alternative to the more invasive lateral window technique in single cases with a minimum of 4 mm of VBH below the maxillary sinus.

Radiographic Detection of the Relationship Between Tonsilloliths and Dental Plaque-Related Pathologies in a Series of Digital Panoramic Radiographs

Objective: The purpose of this study was to analyse the prevalence of tonsilloliths and to determine radiographically whether there is a relationship between tonsilloliths and dental plaque-related pathologies in a series of digital panoramic radiographs. Materials and Methods: This retrospective study included digital panoramic radiographs of 859 patients admitted for a routine dental examination. The panoramic images were examined for both the presence of tonsilloliths and the number of decayed, missing, restored tooth and apical periodontitis. Periodontal bone loss was also measured in thirds of optimal bone height according to the root length and finally a percentage of bone loss was obtained for each panoramic radiograph evaluated. Results: Tonsilloliths were observed in 141 (16.4%) of all individuals. While there was no significant difference regarding the number of decayed teeth and restored teeth between tonsillolith cases (TT) and cases without tonsillolith (TC), the number of missing teeth and apical periodontitis in TT was significantly higher than TC (p: 0.004, p: 0.030, respectively). There was a significant difference between the groups in terms of the mean percentage of bone loss (p: 0.001; p< 0.05). In addition, cases showing bone loss between one-third and two-thirds of the optimal bone height in the TT group (52.5%) were significantly higher than those in TC (45.5%) (p: 0.035; p< 0.05). Conclusion: The relationship between dental plaque-related pathologies and tonsilloliths, observed in this retrospective study, should be confirmed by Computed Tomography studies and randomized, prospective, clinical trials conducted in a multidisciplinary manner.

Effectiveness of a Nanohydroxyapatite-Based Hydrogel on Alveolar Bone Regeneration in Post-Extraction Sockets of Dogs with Naturally Occurring Periodontitis

Pathological mandibular fracture after dental extraction usually occurs in dogs with moderate to severe periodontitis. A nanohydroxyapatite-based hydrogel (HAP hydrogel) was developed to diminish the limitations of hydroxyapatite for post-extraction socket preservation (PSP). However, the effect of the HAP hydrogel in dogs has still not been widely investigated. Moreover, there are few studies on PSP in dogs suffering from clinical periodontitis. The purpose of this study was to evaluate the effectiveness of the HAP hydrogel for PSP in dogs with periodontitis. In five dogs with periodontitis, the first molar (309 and 409) of each hemimandible was extracted. Consequently, all the ten sockets were filled with HAP-hydrogel. Intraoral radiography was performed on the day of operation and 2, 4, 8 and 12 weeks post operation. The Kruskal–Wallis test and paired t-test were adopted for alveolar bone regeneration analysis. The results demonstrated that the radiographic grading, bone height measurement, and bone regeneration analysis were positively significant at all follow-up times compared to the day of operation. Moreover, the scanning electron microscopy with energy-dispersive X-ray spectroscopy imaging after immersion showed a homogeneous distribution of apatite formation on the hydrogel surface. Our investigation suggested that the HAP hydrogel effectively enhances socket regeneration in dogs with periodontitis and can be applied as a bone substitute for PSP in veterinary dentistry.

Influence of Voxel Size on CBCT Images for Dental Implants Planning

Objective This study was developed to evaluate the influence of voxel size on bone measurements for implant planning. Materials and Methods The research was performed by using edentulous synthetic human mandibles with different levels of bone resorption. For each mandible, height and bone thickness were measured with a digital caliper. The PaX-i3d device was used to acquire the volumes of the five mandibles, with 50kVp, 4 mA, and a voxel size of 0.08 mm. After the acquisition, the images were reconstructed in the software CS three-dimensional Imaging, with four different sizes of voxels: 0.1, 0.2, 0.3, and 0.4 mm. All volumes were analyzed by a single evaluator who performed measurements to obtain bone height and thickness, using the reference points that were considered in obtaining the gold standard. The data were analyzed by ANOVA with a significance level of 5%. Results There was no significant difference in the measurements obtained with different voxel sizes, both for bone height measurements and bone thickness. There was no statistically significant difference in measurements in thickness in comparison to the gold standard. Conclusion When necessary, to measure height and bone thickness, it is possible to recommend voxel images of larger size (0.40 mm) without compromising the quality of the patient's clinical planning.

Displacement of the full body of a dental implant into the sinus space without membrane perforation and subsequent osseointegration: a case report

An increasing number of studies have investigated the use of osteotome sinus floor elevation (OSFE) with simultaneous implant placement for maxillary sinus floor residual bone height (RBH) <4 mm. Many studies have reported good clinical results, but very few have reported complications related to this procedure. Here, the case of a 50-year-old female patient with an RBH in the left upper posterior region of 1–4 mm, who underwent OSFE with simultaneous placement of three Bicon short® implants, is described. One of the implants was found to be displaced during the second-stage surgery. The displaced implant was removed using piezosurgery, OSFE with simultaneous implant placement was repeated, and the missing tooth was reconstructed 6 months later. This case suggests that OSFE with simultaneous implant placement is feasible for severely atrophic maxillary sinus floor, but carries a risk of implant displacement.

Efficacy and safety of rhBMP/β-TCP in alveolar ridge preservation: a multicenter, randomized, open-label, comparative, investigator-blinded clinical trial

Background The aim of this multicenter, randomized, open-label, comparative, investigator-blinded study was to investigate the efficacy and safety of recombinant human bone morphogenetic protein 2 (rhBMP-2) combined with β-TCP (rhBMP-2/β-TCP) in alveolar ridge preservation. Materials and methods Eighty-four subjects from three centers were enrolled in this clinical trial. After tooth extraction, rhBMP-2/β-TCP (n = 41, test group) or β-TCP (n = 43, control group) were grafted to the extraction socket with an absorbable barrier membrane for alveolar ridge preservation. Using computed tomography images obtained immediately after and 12 weeks after surgery, changes in the alveolar bone height and width were analyzed for each group and compared between the two groups. Results Both the test and control groups showed a significant decrease in alveolar bone height in the 12 weeks after surgery (both groups, p < 0.0001). However, the test group exhibited a significantly lower decrease in alveolar bone height than the control group (p = 0.0004). Alveolar bone width also showed significantly less resorption in the test group than in the control group for all extraction socket levels (ESL) (p = 0.0152 for 75% ESL; p < 0.0001 for 50% ESL; p < 0.0001 for 25% ESL). There were no statistically significant differences in the incidence of adverse events between the two groups. No severe adverse events occurred in either group. Conclusions The results of this study suggest that rhBMP-2/β-TCP is a safe graft material that provides a high alveolar bone preservation effect in patients receiving dental extraction. Trial registration Clinicaltrials.gov, NCT02714829, Registered 22 March 2016

Comparison Between Two Different Design Concepts of 4- Implant Assisted Mandibular Complete Overdenture:- periimplant bone height changes

Purpose: This study was accomplished to evaluate the bone height changes radiographically and the reliability of use either two posterior short or inclined implants with two conventional anterior implants retaining mandibular overdenture. Materials and methods: Ten male mandibular completely edentulous patients were divided in two equal groups after delivered complete dentures. For the first group (short implant design- group A) two vertical implants were inserted in the canine areas and two short vertical implants were inserted in the 1st molar area. For the second group (inclined implant design- group B) two vertical implants were inserted in the canine areas and two 30o distally inclined implants were inserted in the second premolar area. Digital standardized periapical radiographic assessment for horizontal and vertical alveolar bone height changes was carried out at T0 (immediately), T6 (6 months), T12 (12 months) and after mandibular complete overdenture insertion. Result: 1. VBL decrease significantly with advance of time in both groups during the time intervals. The highest VBL around the implants was noted in the 1st six months followed by the 2nd six months, the highest amount of total VBL observed with the interval T0-T12, followed by the interval (T0-T6) and the inclined implant group showed significant higher total VBL than short implant group at the intervals T0-T6 and T0-12. 2- HBL decreased significantly with advance of time in both groups. For short and inclined implant group, the highest amount of total HBL observed with the interval T0-T12, followed by the interval (T0-T6). Short implant group showed significant higher total HBL than inclined group at the interval T0-T6 and T0-T12. Conclusion: Within the limitations of this clinical radiographic study it can be concluded that (1) The 30o distally inclined implants inserted in the posterior areas for assisting mandibular complete overdenture induce vertical bone loss more than the axially inserted implants (short or conventional implants). (2) The short implants inserted in the posterior areas for assisting mandibular complete overdenture induce horizontal bone loss more than the axially inserted implants. Keywords: Short implants, O-ring ball attachment, VBL, HBL.

Overdentures Supported by Mini or Conventional Implants-effect on Patient Satisfaction and Bone Resorption Rates. A Randomized Clinical Trial

AIM: The aim of the study was to assess the difference between patient satisfaction and bone height changes of mini-implant supported overdentures in comparison with conventional implant after bone expansion technique. METHODS: This randomized clinical trial contains 36 edentulous participants with thin mandibular ridges randomly divided to receive 2 mini-implants, or 2 conventional implants after ridge splitting, both treatments were done in the inter-forminal area of the anterior mandible. Then, the patients received mandibular overdentures with ball and socket attachments. At base line, after 6 and 12 months of loading the implants, patients’ satisfaction was evaluated using visual analog scale, in addition to bone height changes using Soredex DIGORA Optime Classic software. RESULTS: There was statistically significant difference in the overall satisfaction between the mini-implants and the conventional implants group; the amount of bone height changes in the mini-implant group was statistically significant less than the conventional implant group at base line, 6 and 12 months. CONCLUSION: Treatment with two mini-implants provides high level of satisfaction and less bone height changes in a follow-up period of 12 months in comparison to conventional implants after ridge expansion.