A Clinical and Histological Study about the Socket Preservation in a Patient under Oral Bisphosphonates Treatment: A Case Report.

The aim of the present study is to assess the clinical and histological healing of a post-extractive alveolus following the procedure for socket preservation, in a patient receiving oral bisphosphonates for more than 6 years. After the extraction, enzymatically-deantigenated horse bone granules and an equine pericardium membrane were used to preserve the tooth socket. The patient was placed on a monthly follow-up in order to monitor the healing process. A 3 mm trephine bur was used to drill the bone for implant site preparation and to collect the bone sample. No signs and symptoms related to osteonecrosis of the jaws were reported. Histological data showed that, after 5 months, the mean percentages of trabecular bone, bone marrow and residual bone graft were respectively 45.74 ± 0.09%, 48.09 ± 0.08%, and 6.16 ± 0.01%. The residual graft material appeared to be osteointegrated and none of the particles appeared to be encapsulated. The present case report supports the guidelines that assume that patients undergoing oral bisphosphonate therapy can be eligible for surgical therapy. More clinical studies with larger sample sizes are needed to support this clinical evidence.

Single-drill implant induces bone corticalization during submerged healing: an in vivo pilot study.

PURPOSE: The aim of the present paper is to evaluate a simplified implant site preparation technique to preserve bone bulk and enhance osseointegration using a new conical self-tapping implant in cancellous bone. MATERIALS AND METHODS: Ten Expander® 3.8 × 10 mm implants (NoDrill®, Milano, Italy) were inserted in the right side (test group) of sheep's iliac crest using only the pilot drill 1.8 mm in diameter. Ten 3.8 × 10 mm Dynamix® implants (Cortex, Shlomi, Israel) were inserted in the right side (control group) of the same animals following the drilling protocol provided by the manufacturer. Histological, histomorphometric, and biomechanical analyses were performed after 2 months. RESULTS: Implants that belonged to the test group showed a %BIC of 70.91 ± 7.95 while the control group implants had a %BIC value of 49.33 ± 10.73. The %BV was 41.83 ± 6.30 in the test group and 29.61 ± 5.05 in the control group. These differences were statistically significant. A phenomenon of osseocorticalization, characterized by more bone volume percentage around implant area than in the neighboring areas, caused by implant threads geometry, was evident in the test group. CONCLUSION: This surgical protocol allows to insert an innovative fixture geometry in low-density bone using only a pilot drill. This technique demonstrated many clinical and histological advantages with respect to standard implant drilling procedures and classical implant geometry.

Correlation Between Implant Geometry, Implant Surface, Insertion Torque, and Primary Stability: In Vitro Biomechanical Analysis.

PURPOSE: Primary implant stability represents the first step for successful osseointegration. The knowledge of the correlation between host bone density, insertion torque, and implant macrogeometry seems to be fundamental to achieve sufficient primary implant bone fixation in each clinical situation. The purpose of this study was to measure, in vitro, the impact of dental implant macrogeometry and insertion torque values on primary stability in relation to different bone densities, representing both the human mandible and maxilla. MATERIALS AND METHODS: One hundred twenty 3.8 ± 11-mm commercial dental implants were used. Forty implants had small threads with a machined neck, 40 implants had small threads with a microthreaded neck, and the last 40 implants had large threads with a reverse neck design. Fresh bovine ribs, representing a medium-dense bone density (D2-D3), and fresh ovine iliac crest, representing a soft bone density (D4), were used. Insertion torque and micromobility under lateral force data were recorded for each implant. RESULTS: In the medium-dense bone type, the reverse neck implant design showed less primary implant stability than the conventional straight implant neck. In soft bone, both implants with the large thread design and microthreaded neck implants showed better implant stability than the implant with a small thread design with a straight machined neck. Implants with large and self-cutting threads showed significantly (P < .05) lower micromobility values than other implants in postextractive sites in low-density bone. CONCLUSION: Implant geometries and bone density are the main factors involved in the degree of primary implant stability. Large-thread implant designs are highly desirable in cases of poor bone quality. Each implant geometry generates an insertion torque value, which is correlated to the stability of that specific implant in a specific bone quality, but the insertion torque is not an objective value to compare primary stability between different implant types.

A New Highly Hydrophilic Electrochemical Implant Titanium Surface: A Histological and Biomechanical In Vivo Study.

PURPOSE: The aim was to compare the osseointegration degree and secondary implant stability between implants with different surface treatments. MATERIALS AND METHODS: A novel electrochemical treatment was applied to modify the sandblasted and acid-etched surface (SLA) to obtain the new hydrophilic Feeling (FEL) surface presenting a highly soluble and homogenous film made of calcium and phosphorus nanocrystals. Twenty 3.8 × 10-mm dynamix implants (Cortex) were inserted in sheep iliac crests. Sheep were killed after 2 months. Bone-to-implant contact percentage (%BIC) and biomechanical parameters, such as implant stability quotient (ISQ) and value of actual micromotion (VAM), were evaluated for each implants. RESULTS: No implant failures were observed. Implants of test group showed %BIC value 30% higher in respect with control group (P = 0.001). No statistical differences were detected between the 2 groups in VAM and ISQ values. CONCLUSION: Both surface treatments were highly osteoconductive because they were able to significantly increase the bone density onto implant surface in respect with that in which they were inserted (D4 bone density). The hydrophilic FEL surface demonstrated an increase of about 216% in BIC in respect with host bone density and an additional 30% more in respect with SLA surface. Faster osseointegration process is desirable in case of early implant loading protocol.

No-Prep Rehabilitation of Fractured Maxillary Incisors with Partial Veneers.

OBJECTIVE: Therapeutic options for dental trauma depend on the injuries' features. For patients with uncomplicated tooth fractures, adhesive materials and composite partial veneers may be a therapeutic solution that completely preserves healthy tooth structure. CLINICAL CONSIDERATIONS: An ultra-conservative approach, using indirect composite partial veneers to restore fractured anterior teeth is described in these case reports. CONCLUSION: Despite the position of the finish line in the middle of the clinical crown, this solution offers functional and esthetic outcomes using an indirect composite technique, and appears to be a suitable alternative to direct composite restorations or less conservative indirect veneers. CLINICAL SIGNIFICANCE: Indirect composite partial veneers present considerable advantages, such as ultra-minimally invasive properties and excellent esthetic appearances. The success seems to depend on a combination of sound adhesive principles, adequate design of the restoration, laboratory experience, and cementation techniques. (J Esthet Restor Dent 28:351-358, 2016).

Validation of value of actual micromotion as a direct measure of implant micromobility after healing (secondary implant stability). An in vivo histologic and biomechanical study.

OBJECTIVES: The osseointegration process replaces the surgically damaged bone with newly formed bone in contact to the implant surface. This involves some loss of primary stability, which will continue until new bone is formed providing a new stability, known as "secondary stability." A direct measurement of secondary implant stability appears fundamental to determine the period and modalities for implant loading. The aim of this study was to validate the measurement of the implant micromotion to test secondary implant stability. MATERIALS AND METHODS: Twenty-four 3.8 × 11.5 mm implants (Dynamix, Cortex, Shlomi, Israel) were inserted in sheep iliac crests. The animals were sacrificed after 2 months, and the freshly retrieved bone blocks were immediately fixed on a customized device to calculate the value of actual micromotion (VAM) according to a previously described technique. Implant stability quotient (ISQ) values, reverse torque value (RTV), %bone-to-implant contact (%BIC), bone volume percentage (%BV) and crestal bone loss (CBL) were also calculated for each implant. Statistical correlations between VAM and the other parameters were calculated. RESULTS: Data correlation analysis between the examined parameters showed that VAM significantly correlates (P < 0.05) to RTV, %BIC, ISQ and CBL. CONCLUSIONS: As VAM showed to be statistical correlated to the other parameters of osseointegration, it may be used to clinically check the amount of implant osseointegration, secondary stability and CBL. Future studies are needed to confirm these results moreover. An instrument to measure VAM in the oral cavity still needs to be developed.

New Osseodensification Implant Site Preparation Method to Increase Bone Density in Low-Density Bone: In Vivo Evaluation in Sheep.

PURPOSE: The aim of this study was to evaluate a new surgical technique for implant site preparation that could allow to enhance bone density, ridge width, and implant secondary stability. MATERIALS AND METHODS: The edges of the iliac crests of 2 sheep were exposed and ten 3.8 × 10-mm Dynamix implants (Cortex) were inserted in the left sides using the conventional drilling method (control group). Ten 5 × 10-mm Dynamix implants (Cortex) were inserted in the right sides (test group) using the osseodensification procedure (Versah). After 2 months of healing, the sheep were killed, and biomechanical and histological examinations were performed. RESULTS: No implant failures were observed after 2 months of healing. A significant increase of ridge width and bone volume percentage (%BV) (approximately 30% higher) was detected in the test group. Significantly better removal torque values and micromotion under lateral forces (value of actual micromotion) were recorded for the test group in respect with the control group. CONCLUSION: Osseodensification technique used in the present in vivo study was demonstrated to be able to increase the %BV around dental implants inserted in low-density bone in respect to conventional implant drilling techniques, which may play a role in enhancing implant stability and reduce micromotion.

Effect of Implant Thread Geometry on Secondary Stability, Bone Density, and Bone-to-Implant Contact: A Biomechanical and Histological Analysis.

PURPOSE: This study evaluated the effect of 2 different thread designs on secondary stability (micromotion) and osseointegration rate in dense and cancellous bones. MATERIALS AND METHODS: Forty large threaded and 40 small threaded implants (Cortex) were placed in low- (iliac crest) and high-density (mandible) bone of sheep. Two months later, micromobility tests and histological analysis were performed to measure secondary stability, osseointegration (bone-to-implant contact percentage [%BIC]), and bone density (bone volume percentage [%BV]). The value of actual micromotion of implant is introduced as a new parameter to evaluate secondary stability. RESULTS: Large threaded implants showed significantly higher %BIC and %BV than small threaded implants in low-density bone and statistically higher secondary stability in cancellous and cortical bones. CONCLUSIONS: Implants in dense bone reach higher secondary stability than those in cancellous bone, despite the lower %BIC. Implant geometry and bone density play a key role in secondary stability. Large thread design improves bone anchorage mechanically and histologically as compared with small threaded implants.

A retrospective study of clinical and radiologic outcomes of 69 consecutive maxillary sinus augmentations associated with functional endoscopic sinus surgery.

PURPOSE: The aim of this clinical investigation was to evaluate the clinical and radiologic outcomes of a single-step surgical procedure that includes functional endoscopic sinus surgery (FESS) and maxillary sinus elevation by the lateral window approach in patients with reversible contraindications to sinus elevation. MATERIALS AND METHODS: Thirty-eight patients with insufficient bone height in the posterior maxilla caused by pneumatization of the sinus and with reversible ear-nose-throat (ENT) contraindications to sinus elevation were recruited for this investigation between January 2010 and January 2012. All patients were treated in a single session under general anesthesia for a total of 69 consecutive sinus augmentations. FESS was performed by an ENT specialist, and an oral surgeon carried out sinus elevation through the lateral window approach. Particulate xenograft was used beneath the sinus membrane. Intraoperative and postoperative complications (eg, membrane tears, rhinosinusitis, graft infection or loss) were reported. Nasal endoscopies were performed at 7, 14, and 30 days and 3 months after treatment. After a healing period of 6 months, 137 implants were inserted. Computed tomography scans were performed after 6 months and 1 year. RESULTS: Intraoperative membrane perforation occurred in only one case. No implant failures were recorded during the follow-up period. Radiologic and clinical findings showed the resolution of ENT disease and good bone graft integration after 1 year. A relapse of mucosal thickening observed in some patients did not influence the graft healing. CONCLUSION: Preliminary rhinosinusal evaluation by an ENT specialist and computed tomography of the ostiomeatal complex are necessary in patients needing maxillary sinus elevation. A single-step approach to FESS and sinus elevation is a predictable technique to manage patients with ENT reversible contraindications to sinus elevation.

Effect of temperature on the dental implant osseointegration development in low-density bone: an in vivo histological evaluation.

OBJECTIVES: To make an in vivo evaluation of the effects of 2 different bone temperatures, on the development of implant osseointegration, in low-density bone. MATERIALS AND METHODS: Fifteen implant osteotomic sites were prepared in the iliac crests of sheep. Before the implant insertion, 5 sites were heated to 50°C for 1 minute, 5 sites to 60°C for 1 minute, and 5 sites were not overheated. Fifteen titanium dental implants (Cortex, Israel) were inserted. After a healing period of 2 months, the histomorphometric parameters calculated for each implant were the Bone-Implant Contact percentage (%BIC) and the infrabony pocket depth. Unpaired t test was applied to find statistical differences between groups. RESULTS: No implants failed. Statistical significant differences in %BIC and periimplant bone loss were found between the 60°C group and control group. No significant differences were found between the 50°C group and control group, although bone suffering signs were present. CONCLUSION: An osteotomic site overheating up to 60°C for 1 minute in low-density bone, before implant insertion, did not lead to implant failure, but it induced significant crestal bone loss during healing and lower %BIC.

Effect of 50 to 60°C heating on osseointegration of dental implants in dense bone: an in vivo histological study.

OBJECTIVES: To evaluate, in vivo, the effects of bone temperatures increased up to 60°C introduced before implant insertion on titanium implant osseointegration. MATERIALS AND METHODS: Twenty-four acid etched and sandblasted implants (Cortex Dental Implants) were inserted in the inferior edge of sheep mandibles. Osteotomic sites were randomly divided into 3 groups before inserting the implant. In test 1 group and in test 2 group, implant sites were overheated, respectively, up to 50°C for 1 minute and 60°C for 1 minute, with an electronic controlled probe of 3 mm in diameter and 10 mm in length. Osteotomic sites in control group were not overheated. Implants were inserted according to standard procedures. After 2 months healing, % bone implant contact (%BIC) and infrabony pockets' depth were measured. Unpaired t test was applied to find statistical differences between groups. RESULTS: No implant failure occurred. No statistical significant difference in %BIC was found among groups. Histological analysis showed that mean infrabony pockets were statistically deeper in 60°C group than in other groups. CONCLUSIONS: Bone temperature up to 60°C for 1 minute does not seem to significantly impair titanium dental implant osseointegration. Bone damage signs evident in the 60°C group suggest that careful drilling procedure with sufficient irrigation is necessary to avoid periimplant infrabony pockets' formation. More in vivo evaluations are needed to identify what is the value of bone temperature increase for irreversible inhibition of implant osseointegration.

Insufficient irrigation induces peri-implant bone resorption: an in vivo histologic analysis in sheep.

OBJECTIVES: To measure in vivo impact of dense bone overheating on implant osseointegration and peri-implant bone resorption comparing different bur irrigation methods vs. no irrigation. MATERIALS AND METHODS: Twenty TI-bone implants were inserted in the inferior edge of mandibles of sheep. Different cooling procedures were used in each group: no irrigation (group A), only internal bur irrigation (group B), both internal and external irrigation (group C), and external irrigation (group D). The histomorphometric parameters calculated for each implant were as follows: %cortical bone-implant contact (%CBIC) and %cortical bone volume (%CBV). Friedman's test was applied to test the statistical differences. RESULTS: In group A, we found a huge resorption of cortical bone with %CBIC and %CBV values extremely low. Groups B and C showed mean %CBIC and %BV values higher than other groups The mean %CBV value was significantly different when comparing group B and group C vs. group A (P < 0.05). Significant differences in %CBIC were found also between group C and group A (P < 0.05). CONCLUSIONS: Thermal injury, due to insufficient irrigation, of hard bone caused massive resorption of the cortical bone and implant failure. Drilling procedures on hard bone need an adequate cooling supply because the bone matrix overheating may induce complete resorption of dense bone around implants. Internal-external irrigation and only internal irrigation showed to be more efficient than other types of cooling methods in preventing bone resorption around implants.

Machined and sandblasted human dental implants retrieved after 5 years: a histologic and histomorphometric analysis of three cases.

OBJECTIVE: Human retrieved implants with an intact bone-implant interface play a pivotal role in validating data obtained from in vitro studies and animal experiments. This study presents a histologic and histomorphometric analysis of peri-implant tissue reactions and of the bone-titanium interface in three machined and sandblasted dental implants retrieved after a 5-year loading period. METHOD AND MATERIALS: Three implants, with an intact bone-implant interface, were found in the Archives of the Implant Retrieval Center of the Dental School of the University of Chieti-Pescara, Chieti, Italy. The three implants had been used in a two-stage submerged procedure and loaded as part of a small prosthetic restoration. One implant had been retrieved because of an abutment fracture, while there was a fracture of the connecting screw in the other two. One implant was in the maxilla (sandblasted surface), and two were in the mandible (one with a machined surface and the other with a sandblasted surface). All implants had been processed for histology. RESULTS: All three implants presented mature, compact, lamellar bone at the interface. Many remodeling areas were present in the peri-implant bone, especially inside the implant threads. The bone was always in close contact with the implant surface. The bone-implant contact percentage of the machined implant was 92.7%, while the two sandblasted implants showed bone-implant contact percentages of 85.9% and 76.6%. CONCLUSION: The present histologic results confirmed that these implants with different surfaces maintained a good level of osseointegration over a 5-year loading period, with continuous remodeling at the interface, and showed high bone-implant contact percentages.