The conometric concept for the definitive rehabilitation of a single posterior implant by using a conical indexed abutment: A technique.

This report describes the restoration of the healed single implant in the posterior region by using a lithium disilicate crown supported by an Acuris abutment. The restored implants were placed in the premolar and molar region of both the mandible and the maxilla by using a 1-stage approach. The definitive Acuris abutment was placed after an implant healing period of at least 3 months. Definitive impressions were made at least 3 months after surgery. The precrystallized lithium disilicate crown was adapted to a laboratory abutment and evaluated. The crown was then crystallized, finished, colored, and cemented to the definitive abutment by using an adhesive resin cement. The definitive restoration engaged the abutment without the use of screws or cement. A single healed implant can be successfully restored by using a lithium disilicate restoration supported by an Acuris abutment.

Guided-welded approach planning using digital scanning technology for combined screw- and conometric-retained implant-supported maxillary prosthesis.

AIM: The goal of this case series was to evaluate the clinical outcome at the 2-year follow-up of immediately loaded combined screw- and conometric-retained implant-supported full-arch restorations virtually planned using digital scanning technology. MATERIALS AND METHODS: This series included 12 patients presenting hopeless teeth in the maxilla treated with computer-guided flapless implant placement. A total of 72 implants were inserted. All implants were immediately loaded with a complete-arch restoration supported by an intraorally welded framework. Digital scanning technology was used to virtually plan a combined screw and conometric retention of the frameworks. Clinical parameters were assessed at 1 week and at 1, 3, 6, 12, and 24 months follow-up. RESULTS: The survival rate after 2 years was 98.6%, as one implant failed during the osseointegration period. No major prosthetic complications were observed such as issues with mobility, unscrewed abutments, disconnected conometric copings, and prosthetic fracture. Only one patient registered the chipping of a prosthesis. CONCLUSION: Based on the results of the present study, the use of combined screw and conometric retention for fixed immediate restorations properly planned using digital scanning technology seems to be a viable treatment alternative to screw or conometric retention alone for immediately loaded rehabilitations.

Guided-welded approach planning using a computer-aided designed prosthetic shell for immediately loaded complete-arch rehabilitations supported by conometric abutments.

In guided surgery, implants can be planned from radiographic guide information according to a restoratively driven treatment plan. Unfortunately, the palatal or lingual surface of teeth cannot be easily identified. The present article describes the use of a digitally designed prosthetic shell to improve the accuracy of guided-welded approach planning for immediate restorations supported by conometric abutments. Importing the virtual shell into the planning software provides an effective protocol for using the definitive prosthetic space information to plan the framework shape and position predictably. This method increases the accuracy of virtual planning and reduces the time needed to reline the prosthetic shell.

The Conometric Concept: A Two-Year Follow-Up of Fixed Partial CEREC Restorations Supported By Cone-In-Cone Abutments.

PURPOSE: To evaluate the performance of definitive, implant-supported, lithium disilicate fixed dental prostheses (LS2 FDPs) manufactured with a computer-assisted design/computer-assisted manufacturing (CAD/CAM) system. All patients received two-unit restorations placed in posterior regions, supported by osseointegrated implants with cone-in-cone connection abutments. MATERIALS AND METHODS: Two implants (Ankylos) were placed into healed sites or fresh extraction sockets in the maxillary/mandibular posterior regions of partially edentulous patients. Definitive digital impressions were made 3 months after surgery. Twenty-four patients received fixed  monolithic LS2 restorations manufactured with the CEREC system. All restorations were connected to the implants using cone-in-cone connection abutments. Peri-implant pocket depths were recorded for 2 years at each follow-up visit. Esthetic, functional, and biologic United States Public Health Services (USPHS) parameters modified by the FDI World Dental Federation study design were assessed yearly until the last follow-up appointment. The opposing dentitions were identified by type of restoration and supporting structures at the time of placement of the definitive restorations and at the 2-year follow-up visits. RESULTS: One patient (4.16%) moved to an unknown location during the study. A total of 23 FDPs (95.8%) supported by 46 implants reached the 2-year follow-up. None of the prostheses failed, or became loose or detached. No significant difference involving probing levels between the experimental times were found. CONCLUSIONS: The results of this research indicated that the abutment-prostheses connection using a cone-in-cone approach was successful within the 2-year period of this study. None of the studied monolithic LS2 glass-ceramic prostheses milled using the CEREC CAD/CAM system fractured or became detached.

Implementation of computer-guided implant planning using digital scanning technology for restorations supported by conical abutments: A dental technique.

Conometric retention has recently been proposed as an alternative to cement- or screw-retention for fixed restorations. Conometric copings can only compensate for slightly nonparallel placement without interfering with retention. This article describes a method of using digital scanning technology to facilitate computer-guided implant planning when an immediate restoration supported by conical abutments is planned with a guided-welded approach. The procedure involves importing the scan data of the conometric coping and of the definitive cast obtained from the surgical template into the implant planning software. This approach increases the accuracy of computer-guided implant planning and reduces the time needed for the surgery.

The Conometric Concept: Definitive Fixed Lithium Disilicate Restorations Supported by Conical Abutments.

PURPOSE: The use of the conical coupling connection to support definitive restorations was evaluated in cases involving full acrylic resin or hybrid acrylic resin-composite prostheses. The aim of this study was to evaluate the performance of definitive fixed partial prostheses made with lithium disilicate and supported by coupling connection abutments and healed implants. MATERIALS AND METHODS: The prostheses were placed in the posterior regions of partially edentulous patients; 65 patients received fixed lithium disilicate restorations splinted with conical coupling connections to two implants. Implants were placed into healed sites and fresh extraction sockets. The prostheses were placed after healing periods of 3 months: restorations were followed yearly for 3 years. At each follow-up visit, peri-implant bone levels and pocket depths were recorded. Esthetic, functional, and biologic United States Public Health Services (USPHS) parameters modified by the FDI World Dental Federation study design were assessed at the last follow-up appointments. RESULTS: Two prostheses (3.07%) fractured: one was related to framework design error; one was caused by a car accident. Three patients reported small chips: these restorations were immediately polished. No significant difference involving peri-implant bone and probing levels between the experimental times were found. None of the prostheses became loose. CONCLUSIONS: The results of this research indicated that abutment-prostheses coupling connections were successful within the timeframe of this study.

Marginal bone loss around implants with platform-switched Morse-cone connection: a radiographic cross-sectional study.

OBJECTIVES: The aims of the present cross-sectional study are to evaluate the bone remodeling around Morse-cone implants placed subcrestally 1 year after loading and the prevalence of bone loss >0.5 mm after at least 3 years of loading. MATERIAL AND METHODS: Subjects who underwent a radiographic check in 2013 with implants that had been in function for at least 3 years were considered for inclusion. The study population comprised of 145 subjects with a total of 523 implants. At the moment of insertion, all the implants were placed subcrestally from 1 to 3 mm as clinically measured. Radiographs taken at baseline, that is 1 year after loading (T0), and at the follow-up visit in 2013 (T1) were examined. The distance between the rim of the implant and the marginal bone level at mesial and distal aspects of each implant was determined and the mean bone loss calculated. RESULTS: In the total sample, the mean bone loss occurred between baseline and 2013 examination was 0.42 ± 0.77 mm; at T1 424 implants presented the marginal bone level at the implant rim (78) or above it (346). On the other hand, 99 implants presented the rim above the bone crest. Fifty-one implants that at T1 presented the rim above the bone crest, and that between T0 and T1 had lost at least 0.5 mm, were considered losers: 10 implants lost up to 0.5 mm, 11 lost from 0.6 to 1 mm, 16 lost from 1.1 to 2 mm, and 14 lost more than 2 mm of bone. On a subject basis, 34 subjects (group A) with a total of 200 implant sites presented loser implants, while 111 subjects (group B) with 323 implants displayed non-loser implants. CONCLUSIONS: Within the limits of a cross-sectional study, the results show that Morse-cone implants placed subcrestally in the vast majority of cases (89.9%) are able to maintain the bone crest at level of the rim or above it 1 year after loading. The incidence of loser sites (bone loss >0.5 mm) after at least 3 years of follow-up is 9.7% at implant level and 23.5% at patient level.

10-year prospective cohort follow-up of immediately restored XiVE implants.

OBJECTIVE: The aim of this prospective cohort study was to assess the ten-year performance of the condensing thread, self-tapping apex and internal hexagonal connection XiVE implant supporting partial fixed prostheses placed with an immediate restoration approach. MATERIAL AND METHODS: All patients received a fixed two- to four-unit partial provisional restoration supported by immediately loaded implants. The final gold alloy/ceramic restorations were cemented approximately 28 weeks after implant insertion. Marginal bone level, pocket probing depth and percentage of bleeding on probing, biological or technical complications and any other adverse events were measured annually up to ten years after surgery. The overall success and survival rates at implant level were evaluated following the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference criteria. Implant placement in post-extractive or healed sites, smoking and a history of periodontal treatment were evaluated to assess whether they had an influence on bone resorption or on implant survival. RESULTS: Of 114 patients, for a total of 284 implants, fulfilled all the inclusion criteria and were enrolled in the study. 78 (27.5%) implants placed in 30 (26.3%) patients were lost to follow-up. Eight of 284 (2.8%) implants failed in 8 of 114 (7.0%) patients: one (12.5% of losses) due to failure to achieve osseointegration and seven (87.5% of losses) due to peri-implantitis. No cluster implant failures were assessed. The failure of the implant caused the failure of the prosthesis due to the strategic position of the implant in four patients. At the final ten-year follow-up, 121 (61.4%) implants exhibited a "full success" status with an optimal health condition, 21 (10.9%) implants scored a "satisfactory survival" condition, while 49 (25.49%) of the implants were classified as "compromised survival" status (Misch et al. 2008). Smoking was found to be statistically associated with "implant failure" (P = 0.010), while no association was found for patients treated for periodontal disease (P = 0.679) and post-extractive surgical sites (P = 0.664). Statistically significant more marginal bone loss was found in patients treated for periodontal disease (P < 0.0001). An increased bone loss was also observed in smokers, but the difference with the non-smokers was not statistically significant (P = 0.06). CONCLUSIONS: The XiVE implants can be successfully used to support immediate prosthesis. Patients with a history of periodontitis show increased bone loss and risk to develop peri-implant disease. Smoking seems to jeopardize the long-term implant survival.

Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography.

PURPOSE: The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections. MATERIALS AND METHODS: A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV). RESULTS: In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present. CONCLUSIONS: The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

Periimplant Bone Response in Human-Retrieved, Clinically Stable, Successful, and Functioning Dental Implants After a Long-Term Loading Period: A Report of 17 Cases From 4 to 20 Years.

OBJECTIVE: This study aimed at a histologic and histomorphometric analysis of the periimplant tissues and bone-titanium interface reactions in successfully osseointegrated, clinically stable, and immobile human titanium dental implants retrieved after a long loading period. MATERIALS AND METHODS: In the last 30 months (2013-2015), 21 implants, retrieved from individuals for different causes after a loading period ranging from 4 to 20 years, were sent to the Implant Retrieval Center, University of Chieti-Pescara, Italy. In 4 cases, almost all the bone had been lost during the retrieval, whereas in the remaining 17 cases, mineralized bone was still present. RESULTS: Around the majority of the implants, mature compact bone with few marrow spaces was found. The trabecular bone, constituted by a few thin bone trabeculae, was in a periimplant location around only a few implants. A high percentage of bone-implant contact (BIC) (comprised between 32 ± 4.1% and 83 ± 2.9%) was present. In almost all implants, the space within the threads was almost completely filled by compact lamellar bone or by a thin layer of bone. Close and tight contact between bone and implant surface was observed in all specimens with no gaps or connective tissue at the interface. CONCLUSIONS: All implants appeared to be well integrated in the surrounding mineralized bone, and all of them showed adequate bone-to-implant contact percentages.

Influence of underpreparation on primary stability of implants inserted in poor quality bone sites: an in vitro study.

PURPOSE: The purpose of this present study was to investigate the relation between implant site underpreparation and primary stability in the presence of poor-quality bone. MATERIALS AND METHODS: A study was performed on fresh humid bovine bone; samples presented no cortical layer with a cancellous structure inside and were obtained from the hip. The bones were firmly attached to a base device. Sixty sites were prepared according to the protocol provided by the manufacturer: a 2-mm pilot drill was introduced to the proper depth and then twist drills of 3 and 3.4 mm were used. After site preparation, 20 3.4- × 11-mm (standard protocol group), 20 3.8- × 11-mm (10% undersized group), and 20 4.5- × 11-mm (25% undersized group) implants were inserted at a calibrated maximum torque of 70 N-cm at the predetermined speed of 30 rpm. After implant insertion, variable torque work (VTW), maximum insertion torque (peak IT), and resonance frequency analysis (RFA) values were recorded. RESULTS: The standard protocol group showed a mean VTW of 565.77 ± 219.12 N-cm, a peak IT of 11.3 ± 4.44 N-cm, and an RFA of 69.35 ± 7.35 implant stability quotient (ISQ). The 10% undersized group showed a mean VTW of 1,240.24 ± 407.78 N-cm, a peak IT of 20.26 ± 7.03 N-cm, and an RFA of 73.40 ± 2.33 ISQ. The 25% undersized group showed a mean VTW of 1,254.96 ± 727.49 N-cm, a peak IT of 17.15 ± 10.39 N-cm, and an RFA of 72.30 ± 6.70 ISQ. For VTW, the difference between the standard and undersized protocol values was statistically significant; for peak IT, the difference between the standard and 10% undersized protocol values was statistically significant; no other statistical differences were found between mean values. CONCLUSIONS: In the presence of poor-bone quality, a 10% undersized protocol is sufficient to improve the primary stability of the implant; additional decreases do not seem to enhance primary stability values.

Evaluation of the peri-implant bone around parallel-walled dental implants with a condensing thread macrodesign and a self-tapping apex: a 10-year retrospective histological analysis.

The long-term high percentages of survival and success of dental implants reported in the literature are related mainly to new, innovative implant and thread designs, and new implant surfaces that allow to obtain very good primary and secondary stability in most anatomical and clinical situations, even in low quality and quantity of bone, promoting a more rapid osseointegration. The aim of this retrospective study was a histological and histomorphometrical evaluation of the bone response around implants with a parallel-wall configuration, condensing thread macrodesign, and self-tapping apex, retrieved from man for different causes. A total of 10 implants were reported in the present study, and these implants had been retrieved after a loading period comprised between a few weeks to about 8 years. Mineralized newly formed bone was found at the interface of all the implants, in direct contact with the implant surface, with no gaps or connective fibrous tissue. This bone adapted very well to the microirregularities of the implant surface. Areas of bone remodeling were present in some regions of the interface, with many reversal lines. High bone-implant contact percentages were found. In conclusion, both the macrostructure and the microstructure of this specific type of implant could be very helpful in the long-term high survival and success implant percentages.

Blood vessels are concentrated within the implant surface concavities: a histologic study in rabbit tibia.

Angiogenesis plays a key role in bone formation and maintenance. Bone formation has been reported to initiate in the concavities rather than the convexities in a hydroxyapatite substratum and the implant threads of dental implants. The aim of the present study was to evaluate the number of the blood vessels inside the concavities and around the convexities of the threads of implants in a rabbit tibia model. A total of 32 thread-shaped implants blasted with apatitic calcium phosphate (TCP/HA blend) (Resorbable Blast Texturing, RBT) (Maestro, BioHorizons(®), Birmingham, AL, USA) were inserted in 8 rabbits. Each rabbit received 4 implants, 2 in the right and 2 in left tibia. Implants were retrieved after 1, 2, 4, and 8 weeks and treated to obtain thin ground sections. Statistically significant differences were found in the number of vessels that had formed in the concavities rather than the convexities of the implants after 1 (p = 0.000), and 2 weeks (p = 0.000), whilst no significant differences after 4 (p = 0.546) and 8 weeks (p = 0.275) were detected. The present results supported the hypothesis that blood vessel formation was stimulated by the presence of the concavities, which may provide a suitable environment in which mechanical forces, concentrations and gradients of chemotactic molecules and blood clot retention may all drive vascular and bone cell migration.

Buccal bone plate in immediately placed and restored implant with Bio-Oss(®) collagen graft: a 1-year follow-up study.

OBJECTIVES: The aim of this study was to radiographically assess the vertical and horizontal alterations of buccal alveolar bone after the insertion of a post-extractive implant using Bio-Oss(®) Collagen graft. MATERIAL AND METHODS: The study was designed as a prospective study. Adult patients were eligible for the study if they needed one or more immediately inserted and immediately restored implant replacing teeth to be extracted within region 15-25. After the insertion, the buccal gap was carefully grafted using Bio-Oss(®) Collagen and the implant immediately restored. Cone-Beam Computed Tomography (CBCT) was performed immediately after surgery and a series of measurements were made to determine the dimension of the buccal bone plate and the void between implant and extraction socket. A second CBCT was taken and the measurements repeated after 12 months. RESULTS: Altogether, 69 patients were included in the study; a total of 69 implants were inserted. The study demonstrated that the extraction of a tooth and the immediate insertion of an implant together with an xenograft resulted in alterations of the vertical and horizontal dimension of the buccal bone plate (respectively, 25.6% and 29.3%). Nevertheless, the vertical and horizontal gap reduction was nearly complete (respectively, 99.3% and 99.1%) and the implant was normally in contact with buccal bone. CONCLUSIONS: Implant placement into extraction sockets can result in favorable radiological results even in the presence of evident alterations of the buccal bone wall.

Effect of titanium surface topographies on human bone marrow stem cells differentiation in vitro.

Coating characteristics of dental implants such as composition and topography regulate cell response during implant healing. The aim of this study was to assess how surface topography can affect osteogenic differentiation of mesenchymal stem cells (MSCs) by analyzing the expression levels of bone-related genes and MSCs marker. Thirty disk-shaped, commercially pure Grade 2 titanium samples (10 × 2 mm) with 3 different surface topographies (DENTSPLY-Friadent GmbH, Mannheim, Germany) were used in the present study: 10 Ti machined disks (control), 10 Ti sandblasted and acid-etched disks (DPS(®)) and 10 sandblasted and acid-etched disks at high temperature (Plus(®)). Samples were processed for real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. By comparing machined and Plus(®) disks, quantitative real-time RT-PCR showed a significant reduction of the bone-related genes osteocalcin (BGLAP) and osteoblast transcriptional factor (RUNX2). The comparison between DPS(®) and Plus(®) disks showed a slight induction of all the genes examined (RUNX2, ALPL, COL1A1, COL3A1, ENG, FOSL1, SPP1, and SP7); only the expression of BGLAP remained stable. The present study, demonstrated that implant surface topography affects osteoblast gene expression. Indeed, Plus(®) surface produces an effect on MSCs in the late differentiation stages.

A six-year follow-up of full-arch immediate restorations fabricated with an intraoral welding technique.

PURPOSE: The aim of this study was to evaluate the 6-year effectiveness of maxillary and mandibular full-arch immediately loaded prostheses fabricated using an intraoral welding technique. METHODS: All patients received the same day of surgery a fixed, full-arch prosthesis supported by an intraorally welded titanium framework created directly in the patient's mouth using a titanium bar. Life table analysis of implant survival, complications, and any other adverse events were recorded at yearly follow-up for a period of 6 years. RESULTS: One hundred twenty-four (86.11%) of 144 implants placed in maxillary cases and 87 (77.68%) of 112 implants placed in mandible cases completed the planned 6-year follow-up. At the 72-month follow-up, the accumulated mean marginal bone loss was, respectively, 1.39 mm (SD = 0.67) for the implants placed in the maxilla (n = 124) and 1.29 mm (SD = 0.71) for the implants placed in the mandible (n = 87). Fracturing of the composite resin superstructure was the most common adverse event. CONCLUSIONS: After a 6-year follow-up period, the intraoral welding technique proved to be a predictable technique for successfully rehabilitating the fully edentulous patient with a fixed and immediate prosthesis.

Primary stability determination of implants inserted in sinus augmented sites: 1-step versus 2-step procedure.

OBJECTIVES: The aim of this study was to evaluate the primary stability of implants placed immediately after a sinus lift, compared with implants placed in the area treated with a sinus lift 6 months before. MATERIAL AND METHODS: Patients with a residual bone height of at least 4 mm were treated with a 1-stage procedure (group A) and patients with a residual bone height < 4 mm with a 2-stage approach (group B). Sinus lift was always performed with 50% autogenous bone and 50% deproteinized bovine bone mineral. Data recorded included maximum insertion torque (IT), resonance frequency analysis (RFA) values, and bone density, length, and diameter. It was recorded whether an implant was removed within 6 months after insertion. RESULTS: Fourteen patients were included in group A and 16 patients in group B; 96 implants were inserted. Mean IT was 23.77 ± 12.63 N·cm in group A and 26.48 ± 20.80 N·cm in group B. Mean RFA was 65.25 ± 4.45 implant stability quotient (ISQ) in group A and 67.92 ± 10.99 ISQ in group B. No statistically significant differences were found. All implants were osseointegrated. CONCLUSIONS: The results show that the implants studied can obtain a sufficient primary stability in both clinical situations without statistically significant differences.

A histological and histomorphometrical evaluation of retrieved human implants with a wettable, highly hydrophilic, hierarchically microstructured surface: a retrospective analysis of 14 implants.

PURPOSE: Analysis of human-retrieved implants provides a unique opportunity to evaluate osseointegration processes. There is evidence that faster bone apposition is present at textured surfaces, with a very high success percentage. Aim of the present retrospective analysis was an evaluation of 14 human retrieved from humans implants with a wettable, highly hydrophilic, microstructured surface. MATERIALS AND METHODS: The archives of the Implant Retrieval Center of the Dental School, University of Chieti-Pescara, Italy, were searched, and a total of 14 implants FRIADENT plus surface (Dentsply Implants Manufacturing GmbH, Mannheim, Germany) retrieved after a loading period comprised between 4 and 8 weeks were found. RESULTS: Around all implants, newly formed bone was found in direct contact with the implant surface, with no connective fibrous tissue found at the interface. In all implants, no epithelial downgrowth was present. A very high bone-to-implant contact percentage was found. CONCLUSIONS: The efficacy of dental implants is related to biological and biomechanical stability and to the integration between the bone and the implant. This integration plays the key role in the fixation and anchoring of the implants.

Eight-year results of site retention of anorganic bovine bone and anorganic bovine matrix.

The long-term fate of some biomaterials is still unknown, and the reports present in the literature are not conclusive as to whether these biomaterials are resorbed over time or not. Different reports can be found with regard to the resorption behavior of anorganic bovine bone (ABB). The aim of the present study was to provide a comparative histological and histomorphometrical evaluation, in the same patient, of 2 specimens retrieved from a sinus augmented with ABB and with anorganic bovine matrix added to a cell-binding peptide (PepGen P-15), respectively, after a healing period of 6 months and after 8 years of implant loading, to evaluate the resorption of both biomaterials. A unilateral sinus augmentation procedure with ABB (50%) and with PepGen P-15 (50%) was performed in a 54-year-old male patient. Two titanium dental implants with a sandblasted and acid-etched surface were inserted after 6 months. During this procedure, 2 tissue cores were retrieved from the sinus with a trephine, before implant insertion. After an additional 6 months, a fixed prosthetic restoration was fabricated. One of these implants, after a loading period of 8 years, fractured in the coronal portion and was removed. Both specimens, one retrieved after a 6-month healing period and the other after an 8-year loading period, were treated to obtain thin ground sections. In the 6-month specimen, the histomorphometry showed that the percentage of newly formed bone was 27.2% ± 3.6%, marrow spaces 35.6% ± 2.3%, residual ABB particles 25.1% ± 1.2%, and residual PepGen P-15 particles 12.1% ± 2.2%. In the 8-year specimen, the histomorphometry showed that the percentage of newly formed bone was 51.4% ± 4.8%, marrow spaces 40% ± 7.1%, residual ABB particles 6.2% ± 0.7%, and residual PepGen P-15 particles 2.4% ± 0.5%. Both biomaterials underwent significant resorption over the course of this study.

Primary Stability Evaluation of a Novel Tapered Implant Inserted in Low-Density Bone Sites: An In Vitro Study.

Purpose: To evaluate primary stability of a new dental implant design in low-density bone sites, compare it with another implant design previously studied in the same bone density, and explore possible correlations between primary stability parameters. Materials and Methods: The study was carried out on fresh humid bovine bone classified as type III. The test group consisted of 30 DS Prime Taper implants (PT), and the control group consisted of 30 Astra Tech EV implants (EV). All the implants were inserted according to the protocol provided by the manufacturer. After placement, variable torque work (VTW), peak insertion torque (pIT), and resonance frequency analysis (RFA) were recorded. Results: Mann-Whitney test showed that the mean VTW and pIT were significantly higher in the test group PT compared to the control group EV; furthermore, statistical analysis showed that the mean RFA was slightly higher in the control group EV but without reaching statistical significance. Pearson correlation analysis showed a very strong positive correlation between pIT and VTW values in both groups; furthermore, it showed a positive correlation between pIT and RFA values and between VTW and RFA values again in both groups. Conclusion: The results showed that the novel tapered implants were able to reach good primary stability in low-density bone sites and that this was superior to parallel-walled implants when measured with VTW and pIT. Moreover, a statistically significant correlation was found between the three methods used to measure implant primary stability.