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To ensure the prevention of thermal trauma and tissue necrosis during bone drilling in surgical procedures, it is crucial to maintain temperatures below the time- and temperature-dependent threshold of 50 °C for 30 s. However, the absence of a current standard for assessing temperatures attained during bone drilling poses a challenge when comparing findings across different studies. This article aims to address this issue by introducing a standardized testing method for acquiring thermal data during experimental bone drilling. The method requires the use of three controlled variables: infrared thermography, standard bone blocks, and a regulated drilling procedure involving a drill press with irrigation that simulates a surgeon. By utilizing this setup, we can obtain temperature data that can be effectively applied in the evaluation of other variables, such as surgical techniques or drill bit design, and translate the data into bone damage/clinical outcomes. Two surgical drill bits (2.0 mm-diameter twist drill bit and 3.3 mm-diameter multi-step drill bit) are compared using this experimental protocol. The results show the 2.0 mm bit reached significantly higher temperatures compared to the 3.3 mm bit when preparing an osteotomy (p < 0.05). The 2.0 mm drill bit reached temperatures over 100 °C while the 3.3 mm drill bit did not exceed 50 °C.

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Digital implant workflows are facilitating new and more accurate methods of implant treatment planning when compared to conventional analog techniques. The placement of implants using guided surgery presents multiple benefits for immediately restoring a patient functionally and esthetically with a provisional restoration. Although digital technology enables efficiency and enhanced accuracy for dental implant treatments, some cases may require the use of a hybrid workflow that employs both conventional and digital procedures, as some limitations to a fully digital approach exist depending on the clinical situation. This article presents several different implant treatment scenarios and discusses whether a fully digital workflow is possible and/or beneficial in each situation. The scenarios describe the full-treatment sequence for immediately loaded implants, allowing a direct comparison of various restorative and surgical implant workflows.

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The design and development of today's dental implants has been an evolving process based on scientific research, clinician input, and manufacturer ingenuity. Newer tapered implants with aggressive thread designs allow for placement at greater torque values than in the past, with high levels of initial stability even in situations with low-density or compromised bone. Modern implants are designed for patient cases involving extraction, immediate placement, and immediate load, as well as cases with less-than-ideal bone volume and quality. Contemporary implant body and platform design strongly considers minimizing bone trauma and crestal bone loss while maintaining gingival architecture. Even the most advanced implant design, however, can only function well when the implant is placed in healthy surrounding bone. Current thought leans toward the notion that implant bed preparation is as important as the implant itself. This article discusses the rationale behind the influence of these modern-day factors in immediate loading and aims to assist clinicians in decision making regarding appropriate selection of implants, instrumentation, and clinical procedures.

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This article describes a technique for digitally recording centric relation using an intraoral scanner based on conventional clinical procedures and discusses the advantages and disadvantages of such a recording.

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This study combines finite element method and animal studies, aiming to investigate tissue remodelling processes around dental implants inserted into sika deer antler and to develop an alternative animal consuming model for studying bone remodelling around implants. Implants were inserted in the antlers and loaded immediately via a self-developed loading device. After 3, 4, 5 and 6 weeks, implants and surrounding tissue were taken out. Specimens were scanned by µCT scanner and finite element models were generated. Immediate loading and osseointegration conditions were simulated at the implant-tissue interface. A vertical force of 10 N was applied on the implant. During the healing time, density and Young's modulus of antler tissue around the implant increased significantly. For each time point, the values of displacement, stresses and strains in the osseointegration model were lower than those of the immediate loading model. As the healing time increased, the displacement of implants was reduced. The 3-week immediate loading model (9878 ± 1965 µstrain) illustrated the highest strains in the antler tissue. Antler tissue showed similar biomechanical properties as human bone in investigating the bone remodelling around implants, therefore the use of sika deer antler model is a promising alternative in implant biomechanical studies.

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The aim of this study was to evaluate the soft tissue thickness and marginal bone loss around dental implants with sloped micro-threaded shoulder (30° angle) in comparing with conventional design, inserted 30° degrees angulated in post extraction sockets and immediate loaded with temporary prosthesis simulating the all-on-four protocol. Materials and Methods: Six fox hound dogs received forty-eight post extraction dental implants with the different diameter and length (Medentika, Germany), but with different neck configurations. Two group of implants were inserted 1mm subcrestal [corrected]. Control group has a micro-threaded neck and the Test group has a sloped microthreaded neck. Immediate loading was applied using a constructed metallic structure. After three months, soft and hard tissue levels were assessed by histomorphometric analysis. Results: The mean soft tissue thickness (STT) was 2.5 ± 0.2 mm for the Control group and 3.3 ± 0.3 mm for Test group (p = 0.036), meanwhile the mean marginal bone loss (MBL) was 1.53 ± 0.34 mm for Control group and, 1.62 ± 0.22 mm for Test group (p > 0.05). Conclusions: Within the limitations of this experimental model in dogs, the findings showed that dental implants with microthreaded and microthreaded sloped necks installed in immediate post extraction sites with immediate load, presented a comparable perimplant tissue behavior.

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Since their introduction, guided dental implant planning and surgery procedures, like most new techniques in medicine and dentistry, have undergone many modifications and advances. While some practitioners were early adopters, most dental surgeons have been cautious regarding this methodology. Despite more than a decade of literature, podium presentations, advances in instrumentation and technique, and successful cases, questions remain within the dental surgical community. This article attempts to address some of these by outlining common but erroneous beliefs about this technology and procedure.

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PURPOSE: To evaluate stability and success rate of hydrophilic nanostructured implants placed via osteotome sinus floor elevation (OSFE) without grafting material or using ß-tricalcium phosphate (ß-TCP), deproteinized bovine bone (DBB), or their combination, and also to assess three-dimensional volumetric stability of endo-sinus bone gained in the aforementioned conditions. MATERIALS AND METHODS: OSFE with simultaneous implant placement (10-mm long SLActive-BL® , Straumann, Basel, Switzerland) was performed. Grafting materials were randomly allocated to implant sites, whereas one site was left without graft. Implant stability was measured by resonance frequency analysis over 6 months. Implant success was evaluated after 2 years of loading. Volume of new endo-sinus bone was calculated from CBCT images using 3D Slicer® software. RESULTS: A total of 180 implants were inserted into posterior maxilla of 45 patients with 6.59 ± 0.45 mm of residual bone height, and all remained successful after 2 years. Implant stability steadily increased during healing, without significant difference between groups (p = .658). After 2 years, endo-sinus bone significantly shrank (p < .001) in all groups (DBB:66.34%; ß-TCP:61.44%; new bone formed from coagulum: 53.02%; ß-TCP + DBB:33.47%). CONCLUSIONS: Endo-sinus bone gained after OSFE inevitably and significantly shrinks regardless of whether grafting material is applied or not. Grafting material offers no significant advantage to stability nor clinical success of hydrophilic and nanostructured implants placed simultaneously with OSFE.

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BACKGROUND: Narrow-diameter implants provide an alternative to the horizontal augmentation techniques situations severe bone atrophy. Lack of bone width and interdental space has been regarded as an encumbrance in the case selection for prosthetic rehabilitation using dental implants. OBJECTIVE: The aim of the study was to evaluate bone-to-implant contact and marginal bone loss of two different narrow implants in resorbed ridges at different crestal positions. MATERIAL AND METHODS: 48 Bredent Narrow(®) implants (24 MiniSky(®) and NarowSky(®) ) were placed at crestal and subcrestal levels in healing bone of atrophic alveolar ridge of 6 American foxhounds. Histological and histomorphometric analyses of osseointegration were carried out at 4 and 8 weeks. RESULTS: Modeling in the marginal defect region was accompanied by marked decreases in the dimensions of both the buccal and the more lingual bone walls. Relative to BIC, significant differences were found in favor of subcrestal group, for both Narrow Sky and MiniSky. Linear measurements showed to be slightly high in the crestal group. With significant differences for PM-IS (peri-implant mucosa to implant shoulder) and IS-BC (implant shoulder to buccal bone crest). CONCLUSIONS: Within the limitations of animal study, it can be stated that the NarrowSky(test group) crestal and subcrestal implants showed less crestal bone resorption, higher ISQ values and most BIC at 4 and 8 weeks of evaluation compared with MiniSky implants (control group). The design of the implants plays an important role in peri-implant mucosa and crestal bone maintenance at 8-week follow-up period.

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Although computed tomography (CT)-guided technology has been shown to increase implant placement accuracy, decrease surgical complications, and improve the predictability of implant case outcome, many in the dental implant community continue to resist using it for three main reasons: time, money, and fear. While it is true that there are additional preparatory steps necessary in patient case planning and the practitioner must invest in unfamiliar technologies and overcome a learning curve, increased efficiency, improved restorative outcomes, and clear benefits to both patients and practitioners make a strong case for adopting this approach.

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OBJECTIVE: The objective of this study was to evaluate the osseointegration and crestal bone loss (CBL) in two implant designs with different diameters (Mini Sky® and Narrow Sky®) implants, placed at different vertical levels at healed canine ridges. MATERIAL AND METHODS: The second, third, and fourth mandibular premolars of six Beagle dogs were extracted bilaterally. After 2 months healing, four implants divided into two groups according to their diameters (i.e., Narrow Sky® and Mini Sky®) were placed in each hemi-mandible at the level of the bone crest or 2 mm subcrestally. The animals were euthanized at 12 weeks and undecalcified samples were processed for histology. Histomorphometric analysis was carried out to compare bone-to-implant contacts (BIC) and crestal bone loss (CBL). RESULTS: There were not significant differences in CBL between groups when the implants were placed at subcrestal bone level (p > 0.05), meanwhile the CBL was significantly higher for both groups when the implants were inserted at crestal level (p < 0.05). All implants were osseointegrated presenting a minimum BIC percentage of 56%. The major percentages of BIC were found for both groups at subcrestal level (p < 0.05). CONCLUSIONS: Within the limitations of this experimental study may be concluded that the implant diameter does not affect the CBL. BIC values are affected by implant diameter and design been higher for narrow implants compared to mini-implants. Subcrestal insertion of both implants favors crestal bone preservation but crestal insertion of both designs is associated with crestal bone loss CLINICAL RELEVANCE: The study shows that narrow implants protect peri-implant crestal bone.

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OBJECTIVES: This study evaluated the effect of implant macrodesign and position, related to the bone crest, on bone-to-implant contact (BIC) and crestal bone (CB) in immediate implants. MATERIAL AND METHODS: The study comprised of six foxhound dogs in which 48 immediate implants were placed. Three types of implants from the same manufacturer with similar surface characteristics but different macrodesigns were randomly placed: Group A (external hex with no collar microthreads), Group B (internal hex and collar microrings), and Group C (internal conical connection and collar microrings). Half of the implants were placed leveled with the bone crest (control) and the remaining, 2 mm subcrestally (test). Block sections were obtained after 12 weeks and processed for mineralized ground sectioning. Statistical analysis consisted of nonparametric Friedman and Wilcoxon test. RESULTS: All implants were clinically stable and histologically osseointegrated. Mean BIC percentage within the control group was as follows: A: 42.52 ± 8.67, B: 35.19 ± 18.12, and C: 47.46 ± 11.50. Within the test group: A: 47.33 ± 5.23, B: 48.38 ± 11.63, and C: 54.88 ± 11.73. Differences between each subgroup in the test and the control groups were statistically significant. BIC was statistically significantly higher in the test (50.588 ± 8.663) than in the control (43.317 ± 9.851) group. Within both groups, differences between group C and the other 2 were statistically significant. Distance from the implant shoulder to the buccal CB was statistically significantly larger in the control than in the test group and between subgroups B and C in the control and test groups. Within the test groups, relative bone gain was noticed. CONCLUSIONS: Subcrestal immediate implant positioning may lead to a relatively reduced CB resorption and increased BIC. Implants macrodesign with crestal microrings may enhance BIC in post-extraction implants.

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OBJECTIVES: To study the peri-implant bone organization pattern of immediately loaded (IL) zirconia implants with microgrooved surfaces. MATERIALS AND METHODS: Forty-eight dental implants of 4 mm diameter and 10 mm length were inserted after two months postextraction healing in the edentulous mandible of six dogs. Three groups of sixteen implants were used, titanium implants (Control), zirconia implants (test A), and zirconia-microgrooved implants (test B), which were loaded immediately. After 4-month healing period, implant-bone samples were processed and analyzed by circularly polarized light (CPL) and confocal laser scanning microscopy (CLSM) in two regions of interest ROI1 (to evaluate the interthread bone) and ROI2 (to evaluate the bone adjacent to the threads) of 1 mm thickness × 10 mm length each one. RESULTS: Bone organization differs near to the test B, compared with test A and control surfaces, active remodeling was detected surrounding test B implants, with alternancy of organized zones, meanwhile controls and test A areas showed organized areas mainly at 2 mm of implant surfaces. Transverse collagen fibers were significatively higher at ROI1 for test B implants (60.34 ± 4.34%), compared with controls (47.25 ± 3.51%) and test A (43.78 ± 2.78%) groups (P < 0.05). Meanwhile, it was not found any significant difference between groups in ROI2 (P > 0.05). CLSM confirmed the presence of collagen mineralized matrix inside microgrooves of test B groups. 3D reconstruction showed blood vessels in direct contact with the implant surfaces of all groups and bone and blood vessels penetration inside the microgrooves in test B group. CONCLUSION: The organized pattern of the microgrooved surfaces is able to induce transverse collagen fiber microenvironment reaction to the load, being positive to promote and to maintain the bone remodeling; in addition blood vessels and bone cells are able to penetrate microgrooved surfaces.

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PURPOSE: To describe contact, thickness, density, and orientation of connective tissue fibers around healing abutments of different geometries by means of a new method using coordinates. MATERIALS AND METHODS: Following the bilateral extraction of mandibular premolars (P2, P3, and P4) from six fox hound dogs and a 2-month healing period, 36 titanium implants were inserted, onto which two groups of healing abutments of different geometry were screwed: Group A (concave abutments) and Group B (wider healing abutment). After 3 months the animals were sacrificed and samples extracted containing each implant and surrounding soft and hard tissues. Histological analysis was performed without decalcifying the samples by means of circularly polarized light under optical microscope and a system of vertical and horizontal coordinates across all the connective tissue in an area delimited by the implant/abutment, epithelium, and bone tissue. RESULTS: In no case had the connective tissue formed a connection to the healing abutment/implant in the internal zone; a space of 35 ± 10 µm separated the connective tissue fibers from the healing abutment surface. The total thickness of connective tissue in the horizontal direction was significantly greater in the medial zone in Group B than in Group A (p < .05). The orientation of the fibers varied according to the coordinate area so that internal coordinates showed a higher percentage of parallel fibers in Group A (p < .05) and a higher percentage of oblique fibers in Group B (p < .05); medial coordinates showed more oblique fibers (p < .05); and the area of external coordinates showed the highest percentage of perpendicular fibers (p < .05). The fiber density was higher in the basal and medial areas (p < .05). CONCLUSIONS: Abutment geometry influences the orientation of collagen fibers; therefore, an abutment with a profile wider than the implant platform favors oblique and perpendicular orientation of collagen fibers and greater connective tissue thickness.

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PURPOSE: To evaluate an experimental multistepped drill for single-stage implant site preparation by means of real-time analysis of thermal variations during and postdrilling, and by implant stability evaluation. MATERIALS AND METHODS: Temperature and time were recorded in real time by paired microprobe thermocouples during simulated osteotomy in type 2 bone similes at the cortical and cancellous zones. Three different drilling groups with a new multistepped drill design were compared: Control (2-mm diameter pilot drill + 3.3-mm three-stepped drill + 4.1-mm three-stepped drill); Test A (3.3-mm three-stepped drill); and Test B (4.1-mm three-stepped drill). Implants were inserted, and implant stability was evaluated with the Perio Test Value (PTV). Two-way anova was used to test the independent effects of osteotomy and implant diameter on temperature and stability. RESULTS: All the drills induced thermal changes without significant differences between groups (p > .05). Drilling in cortical bone produced significant increase of the temperatures in a range of 1.8 ± 0.9°C compared with drilling in cancellous bone (p < .05). ΔT temperatures were significantly higher for test groups in cortical and cancellous bone (p < .05); ΔT10 for all groups showed a reduction of the temperature in a range of 1.7 ± 0.3°C without significant differences between groups (p > .05); the mean time to accomplish drilling was significantly longer in the control group (p < .05); test groups took 10 ± 0.3 seconds less to reach the required drilling depth. PTV values were higher in test groups compared with controls (p < .05). CONCLUSIONS: The multistepped drills used for single-stage implant site preparation Increase temperature as in comparison with a conventional incremental protocol; Induce the temperature increment in cortical bone compared with the cancellous bone; Reduce drilling time when a multistepped drill is used alone; and Increase implant stability twofold compared with a conventional incremental protocol.

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PURPOSE: To evaluate the cumulative survival rates (CSRs) of dental implants placed "fully guided" using computed tomography (CT)-guided surgery, including cone beam CT (CBCT). MATERIALS AND METHODS: Records, mountings, wax-ups, and scanning appliances were made for patients to wear during CT/CBCT scans following established manufacturer-guided surgery protocols. Virtual planning was performed using either the NobelProcera/NobelClinician or the SimPlant/Facilitate softwares. Manufacturer-produced stereolithographic guides and implant-specific instrumentation were used to place implants fully guided to planned depths and angulations. Included in the study were 177 patients, who had 796 implants placed fully guided, using 212 surgical guides. RESULTS: Among 796 implants placed, there were 24 failures, for a 96.98% CSR. System CSRs were: NobelActive, 95.87%; Astra OsseoSpeed, 96.72%; NobelReplace Select Tapered, 97.02%; and NobelReplace Select Straight, 100% (P less than 0.05). Maxillary CSR was 97.62%; mandibular CSR was 95.88% (P less than 0.05). CSR for standard implants (10 mm to 13 mm) was 97.3%; short implants (less than or equal to 9 mm) was 95.1% (P less than 0.05), and long implants greater than 13 mm) was 95.2%. Implant diameter CSR was not significant (P greater than 0.05) for any diameter implant. Full-arch immediately loaded CSR (97.18%) was not different compared to full-arch unloaded (97.20%) (P less than 0.05). CONCLUSIONS: 1) Fully guided implant CSR was 96.98%, which is comparable to "freehand" placement; 2) CSRs varied between implant systems; 3) fully guided short and long implants had lower CSRs than standard implants; 4) the diameter of fully guided implants did not affect CSR; 5) fully guided implants in the anterior maxilla and posterior mandible had reduced CSRs; 6) extraction/immediate placement using fully guided surgery had reduced CSRs; and 7) immediate loading fully guided implants did not affect CSRs.

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Recently, porous titanium granules (PTGs) have been indicated for the preservation of the dimensions of post-extraction sockets, as a filler in sinus lift procedures and for the treatment of peri-implant and periodontal defects, based on the osteoconductivity and dimensional stability of the titanium granules. However, there is a lack of information regarding the use of this material in larger defects and in conjunction with membranes. The objective of this study is to test the behavior of PTGs used to fill critical size defects in rabbit tibiae, with and without membranes. Critical defects were created in both tibiae of rabbits, divided randomly into three groups: Group A (defect filled with PTG), Group B (defect filled with PTG+collagen membrane) and a control group (empty defect). After six weeks, histomorphometric analysis was performed. The results showed more defect closures at the cortical area (87.37%±2.2%) and more bone formation at the marrow area (57.6%±1.3%) in Group B, in comparison with the other groups (P<0.05); the use of membranes improved the material stability expressed as more percentages of the original material when membranes were used (P<0.05). Finally, inflammatory reactions were observed when the granules were not protected by membranes. In spite of the limitations of this animal study, it may be concluded that PTG particles are osteoconductive and allow bone growth. The PTG particles must be covered by a membrane, especially when grafting larger defects, in order to control particle migration, promote clot stabilization and separate the PTG graft from undesired soft tissue cells.

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