Fabio Bernardello

Crestal sinus lift with sequential drills and simultaneous implant placement in sites with <5 mm of native bone: a multicenter retrospective study.

Purpose:The aim of this multicenter retrospective clinical study was to evaluate the survival rate of implants placed in the posterior maxilla with a residual bone height of <5 mm. Materials and Methods:One hundred seventeen patients, recruited from 6 different centers, had 134 implants placed below the maxillary sinus. The patient population consisted of 52 men and 65 women ranging in age from 39 to 78 years (mean age, 53.2 years). Sinus lift procedures were performed following a crestal approach using a specific sequence of drills (Coscis technique). All implants were submerged. Periapical radiographs were obtained with a paralleling technique and were digitized. The pattern of bone remodeling was subsequently evaluated. Results:The average (±SD) follow-up time was 48.2 months (±29.30 months; range, 24 to 120 months). Of the original 134 implants placed, 5 implants (3.7%) failed. The implant survival rate was 96.3%. The average residual bone height was 3.46 mm (±0.91 mm) at baseline. The average height of the alveolar crest in the treated implant sites was 9.94 ± 2.29 mm. The radiographic bone gain was 6.48 ± 2.38 mm. Conclusion:The investigation suggests that this crestal drill approach can be a successful sinus lifting procedure in a severe atrophic maxilla with <5 mm of crestal bone height.

Is socket healing conditioned by buccal plate thickness? A clinical and histologic study 4 months after mineralized human bone allografting.

OBJECTIVE The aim of this study was to clinically and histologically analyze the healing of grafted sockets by mineralized human bone allograft (MHBA) and nongrafted sockets, correlating the results with buccal plate thickness. MATERIAL AND METHODS Thirty-one sockets were randomly split into control (CG) and treatment (MHBA grafted) (TG) groups and, subsequently, into four subgroups according to buccal plate thickness: a ≤ 1 mm and b > 1 mm. Ridge thickness, depth, and height were monitored. Four months after, at implant placement, a bone core biopsy for histologic and morphometric analyses was taken. RESULTS The differences of buccal height (TG-a -0.27 and CG-a -1.17 mm) and width (TG-a 0.55 and CG-a 2.67 mm, TG-b 0.12 and CG-b 1.17 mm) were statistically significant. The increase in bone amount CG-b (28.17%) compared with CG-a (16.98%) was statistically significant. Soft tissue amount of TG-b (54.21%) and TG-a (56.91%) was lower than that of CG-b (71.83%) and CG-a (83.01%), both being statistically significant (P = 0.002). CONCLUSIONS The results proved that thin buccal plates had a worse outcome on socket healing and that network formation by MBHA not only predisposes a successful implant insertion but also acts as size keeper.

Maxillary sinus augmentation by crestal access: a retrospective study on cavity size and outcome correlation

OBJECTIVE Cone-beam computed tomography (CBCT) and radiographic outcomes of crestal sinus elevation, performed using mineralized human bone allograft, were analyzed to correlate results with maxillary sinus size. MATERIAL AND METHODS A total of 60 sinus augmentations in 60 patients, with initial bone ≤5 mm, were performed. Digital radiographs were taken at surgical implant placement time up to post-prosthetic loading follow-up (12-72 months), when CBCT evaluation was carried out. Marginal bone loss (MBL) was radiographically analyzed at 6 months and follow-up time post-loading. Sinus size (BPD), implant distance from palatal (PID) and buccal wall (BID), and absence of bone coverage of implant (intra-sinus bone loss--IBL) were evaluated and statistically evaluated by ANOVA and linear regression analyses. RESULTS MBL increased as a function of time. MBL at final follow-up was statistically associated with MBL at 6 months. A statistically significant correlation of IBL with wall distance and of IBL/mm with time was identified with greater values in wide sinuses (WS ≥ 13.27 mm) than in narrow sinuses (NS < 13.27 mm). CONCLUSIONS This study is the first quantitative and statistically significant confirmation that crestal technique with residual ridge height <5 mm is more appropriate and predictable, in terms of intra-sinus bone coverage, in narrow than in WS.

Full-arch vertical reconstruction of an extremely atrophic mandible with "box technique". A novel surgical procedure: a clinical and histologic case report.

Purpose:To describe a new augmentation procedure named “box technique” for bone reconstruction in a severely atrophic jaw with mandibular and mental nerve dehiscence. Material and Methods:The first surgical box technique procedure was performed to augment the atrophic posterior area. Simultaneously, 2 implants were inserted into the interforaminal zone to stabilize the denture. After 6 months, 2 implants were positioned in the regenerated bone, and a second box technique procedure was performed to reconstruct the ridge in the area of fixture exposition. Six months after the second surgery, the patient was rehabilitated with a removable prosthesis retained on 4 implants. Results:The clinical and histologic analyses highlighted outstanding healing resulting from this vertical and horizontal allografting and included complete resorption of poly D,L-lactide meshes and substitution of the mineralized human bone allograft with an excellent quality new bone formation. Conclusions:Results confirm the effectiveness of the technique, which needs a further case series study endorsing its reliability.

Hybrid Implants in Healthy and Periodontally Compromised Patients: A Preliminary Clinical and Radiographic Study

This preliminary clinical and radiographic study examined the survival of, the marginal bone loss (MBL) around, and the influence of prosthetic abutment height (AH) on MBL around hybrid implants placed in two groups of partially edentulous patients: healthy (HPs) and periodontally compromised (PCPs) patients. A total of 93 patients requiring single or multiunit implant restoration, in the mandible or maxilla, were treated while undergoing cement-retained prosthetic restoration. A total of 54 implants (35 in the maxilla and 19 in the mandible) were placed in 45 HPs, and 56 implants (31 in the maxilla and 25 in the mandible) in 48 PCPs. All 110 hybrid implants positioned in pristine bone provided a 100% survival rate in both HPs and PCPs. No statistical differences were recorded comparing the MBL values of maxillae with those of mandibles. In HPs and PCPs, a similar and limited amount of MBL was recorded, and it was found that the higher the AH, the less MBL. In conclusion, results indicate that the hybrid implants examined could reduce the risk of peri-implantitis due to their coronal machined surfaces and improve osseointegration due to their apical rough surfaces.

Minimum Abutment Height to Eliminate Bone Loss: Influence of Implant Neck Design and Platform Switching

PURPOSE This retrospective study quantitatively analyzed the minimum prosthetic abutment height to eliminate bone loss after 4.7-mm-diameter implant placement in maxillary bone and how grafting techniques can affect the marginal bone loss in implants placed in maxillary areas. MATERIALS AND METHODS Two different implant types with a similar neck design were singularly placed in two groups of patients: the test group, with platform-switched implants, and the control group, with conventional (non-platform-switched) implants. Patients requiring bone augmentation underwent unilateral sinus augmentation using a transcrestal technique with mineralized xenograft. Radiographs were taken immediately after implant placement, after delivery of the prosthetic restoration, and after 12 months of loading. RESULTS The average mesial and distal marginal bone loss of the control group (25 patients) was significantly more than twice that of the test group (26 patients), while their average abutment height was similar. Linear regression analysis highlighted a statistically significant inverse relationship between marginal bone loss and abutment height in both groups; however, the intercept of the regression line, both mesially and distally, was 50% lower for the test group than for the control group. The marginal bone loss was annulled with an abutment height of 2.5 mm for the test group and 3.0 mm for the control group. No statistically significant differences were found regarding marginal bone loss of implants placed in native maxillary bone compared with those placed in the grafted areas. CONCLUSION The results suggest that the shorter the abutment height, the greater the marginal bone loss in cement-retained prostheses. Abutment height showed a greater influence in platform-switched than in non-platform-switched implants on the limitation of marginal bone loss.

Piezosurgical treatment of crestal bone: quantitative comparison of post‐extractive socket outcomes with those of traditional treatment

OBJECTIVE The study aimed to quantitatively compare, for the first time, the clinical outcomes of crestal bone volume resorption in sockets undergoing traditional extraction technique (TET) or piezosurgical extraction technique (PET), also considering the influence of buccal plate thickness. MATERIAL AND METHODS In this prospective study, 19 sockets were randomly treated with TET, and 18 sockets were randomly treated with PET. Furthermore, patients were split into subgroup A, with buccal bone plate thickness (BPT) ≤1 mm, and subgroup B, with BPT>1 mm. Buccal (BCH) and palatal (PCH) cortex height, bucco-palatal ridge (BPR) width were monitored at tooth extraction and after the 4-month post-extractive period of natural healing. RESULTS After 4 months, BCH, PCH and BPR width decreased more in the TET than in the PET group, but only the BPR decrease was statistically significant (P = 0.034) after ANOVA test. In both TET and PET groups, all B subgroup patients showed a lower decrease than A subgroup patients for both BCH, PCH and BPR, statistically significant for PCH (P = 0.019) and BPR (P < 0.001) of TET group, and BPR (P = 0.002) of PET group, after ANOVA. Both A and B subgroups of PET showed a statistically significant lower decrease than the corresponding subgroups of TET, comparing A (P = 0.005) and B (P = 0.037) subgroups for BPR, after ANOVA. CONCLUSIONS With both thin and thick buccal plates, the piezosurgical extraction technique of teeth significantly decreases the horizontal resorption of the hard tissue ridge, but not the vertical resorption. Moreover, buccal plate thickness seems to be a key factor in post-extractive bone resorption: the thinner the buccal plate the greater the horizontal crestal bone loss.

Guided "Sandwich" Technique: A Novel Surgical Approach for Safe Osteotomies in the Treatment of Vertical Bone Defects in the Posterior Atrophic Mandible: A Case Report

Purpose:A novel technique to perform safe osteotomies during inlay block regenerative procedures in the posterior atrophic mandible is described. Material and Methods:A 52-year-old male patient with vertical atrophy of the left posterior mandible was treated adopting an inlay block “sandwich” technique using an allogenic cancelous block and a mixture of mineralized and demineralized human bone allograft in putty form as graft. The horizontal osteotomy for the lifting of the osteotomized bone segment was performed using a template prepared from a virtual anatomical replica of the patients mandible obtained from cone beam computed tomography data. In the second surgical phase, 3 months after the augmentation, 2 implants were easily placed. Results:The horizontal osteotomy was carried out, with no risk, very close to the nerve structures after the precise osteotomy line established preoperatively on the three-dimensional computed tomography (3D-CT) virtual reconstruction. No neurological complications were observed in the first days after the procedure, and no subsequent problems were recorded during the 3-month healing period. Conclusion:Radiographic evaluations and complication-free clinical healing demonstrate the effectiveness of this technique to obtain safe and precise osteotomies.

Soft Tissue Enhancement and Implant Placement Following Partial Mandibulectomy Due to Squamous Cell Carcinoma

Many dental procedures allow for implant placement in partially or totally edentulous patients. Despite the availability of various implant and abutment types on the market, it often becomes quite challenging to achieve the biological and esthetic goals in a patient who has ridge deficiencies. Problems arise from the lack of adequate bone quality and quantity. 1 , 2 Soft tissue form and maintenance is also a consideration to evaluate. 3 Primary reconstructive techniques following segmental mandibulectomy is evolving and improves quality of life. A seldom encountered complication is the discovery and treatment of a malignant process (for example, squamous cell carcinoma). Oral squamous cell carcinoma (OSCC) is one of the most aggressive malignancies worldwide and accounts for more than 90% of all oral cancers. 4 It is ranked as the sixth leading cause of cancer mortality worldwide. The most common sites of OSCC are the lateral ventral surface of the tongue, the floor of the mouth and buccal mucosa. For most oral cavity cancers, surgery is the initial treatment of choice (often involving the full or partial removal of bony jaw structure). 5 Radiation or chemoradiation is added postoperatively if disease is more advanced or has high-risk features. Successful cancer therapy can affect the quantity and quality of soft tissue in areas where implants are planned, thus affecting the initial placement and the long-term success of the implants. Complications can be numerous; especially difficult is implant treatment in the mandibular anterior area where inadequate alveolar height results in the lingual floor and the vestibule becoming contiguous. 6 Further complicating treatment is the presence of scar tissue (often found following cancer surgery and radiotherapy). The present case is a report of the combination of a soft tissue enhancement and implant placement following partial mandibulectomy resulting from the treatment of oral squamous cell carcinoma. A video abstract is available for viewing at https://youtu.be/dZ9t3j4ufOc?list=PLvRxNhB9EJqbqjcYMbwKbwi8Xpbb0YuHI .

Stage Characterization and Marginal Bone Loss Evaluation Up to 96 Months of Crestal Sinus Augmentation With Sequential Drills: A Retrospective Study

Introduction:The 2-stage crestal approach to augment the maxillary sinus is a little-used technique. The aim of this retrospective study was to assess events characterizing stages of this technique after implant placement in the posterior maxilla with residual bone height less than 4 mm and evaluate the marginal bone loss (MBL) changes over time. Material and Methods:Thirty-three patients underwent unilateral sinus augmentations using the trancrestal technique with mineralized allograft. Six-months (6 m) after first surgery, if skeletal subsidence prevented insertion of a 10-mm-length implant, additional grafting was performed during implant (n = 33) insertion. Radiographs were taken before grafting (baseline), immediately after and at 6 months; immediately after and 6 months after implant placement; and at follow-up (24–96 m). Results:One implant was lost (ISR = 96.97%). Of the remaining 32 patients, 14 (A group) underwent standard implant placement, whereas 18 (B group) underwent additional grafting immediately before implant placement. Given that B-group patients initially obtained lower crestal bone height after first surgery, additional grafting procedures provided greater crestal height in the B group. A significant relationship between ending (eMBL) and 6mMBL was found in both groups, with greater values in the B group. However, in both groups, eMBL was always greater if 6mMBL was greater than 0.44 mm. Discussion:Results suggest a high and low skeletal-reactivity patient categorization. In both patient categories, MBL greatly depends upon 6-month values. Investigations are necessary to relate sinus size with results obtained by this 2-stage crestal approach. Conclusions:The 2-stage crestal sinus lift procedure not only provides predictable results, but also allows low skeletal-reactivity patient recovery.