A Zygomatic Bone Study Using Virtual Dental Implant Planning Software.

This study evaluated the anatomical factors that influence the virtual planning of zygomatic implants by using cone-beam computerized tomography (CBCT) scans. CBCT scans of 268 edentulous patients were transferred to specialized implant planning software for the following measurements: maxillo-sinus concavity size (small, medium, and large), zygoma width, implant insertion angle, implant length, and implant apical anchorage. Concavity sizes found were as follows: 34.95% small, 52.30% medium, and 7.35% large. The mean insertion angle was 43.2 degrees, and the average implant apical anchorage was 9.1 mm. The most frequent implant length was 40 mm. Significant differences were found when the different types of concavities in relation to the installation angle, the distance of the apical portion of the implant in contact with the zygomatic bone, and the lateral-lateral thickness of the zygomatic bone were compared (P < .001). Medium-sized maxillary sinus concavity presented greater apical anchorage of the implant (9.7 mm) and was the most frequent type (52.30%). The zygomatic bone is a viable site for zygomatic fixtures, and the use of specialized implant planning software is an important tool to achieve predictable outcomes for zygomatic implants and allows good visualization of the relation between implants and anatomical structures.

Factors influencing implant and prosthesis survival in zygomatic implant-supported fixed rehabilitation: a retrospective study.

BACKGROUND: The aim of this retrospective study was to evaluate mid-term implant and prosthesis survival in patients with edentulous atrophic maxillae submitted to zygomatic implant-supported fixed rehabilitation and to identify possible related risk factors. METHODS: Data were collected from records of patients with edentulous atrophic maxillae, in good general health and who were rehabilitated by means of acrylic resin full-arch screw-retained prosthesis supported by at least one zygomatic implant, between the years of 2006-2017. Implant and prosthesis survival rates were calculated. The association between implant and prosthesis loss and quantitative and qualitative variables of interest was verified with t tests and Fisher's exact tests, respectively. For the significant variables in the latter, odds ratio and 95% confidence intervals were additionally calculated. RESULTS: The sample comprised 66 patients in whom 171 zygomatic implants were placed to support maxillary screw-retained full-arch prostheses. Implant and prosthesis survival rates of 94.15% and 92.4%, respectively, were observed in a mean of 3.6 years of follow-up (up to 11.7 years). Implant loss was 4.33 more likely to occur when adverse events were recorded after the procedure of implant placement (P = 0.026) and 10.31 more likely to occur in implants that had their prosthesis repaired during follow-up visits (P = 0.004). Prosthesis loss was 22.00 times more likely to occur when implants were previously lost (P < 0.001). All prostheses that were considered as failures (i.e. were replaced) had been previously submitted to laboratory repair at some point during follow-up. CONCLUSIONS: Zygomatic implant rehabilitation demonstrated to be a reliable method with good mid-term results. The occurrence of post-surgical adverse events and need for laboratory repair of the prosthesis were found to be significant risk factors for implant loss. Previous implant loss was significantly associated with prosthesis loss. These risk factors may be prevented by means of detailed planning of the rehabilitation to be carried out, including post-operative care of the patients, so that treatment success using zygomatic implants can be achieved.

Immediate Oral Rehabilitation Using Dental Implants After Marginal Mandibulectomy: A Case Report.

Mandibular reconstruction techniques are always a challenge to oral and maxillofacial (OMF) surgeons. Techniques and treatment plans that offer the patient OMF rehabilitation should always be available. Technological innovations have enabled more rapid, safer, and more secure treatment than in the past. This article describes a case using a different approach. The patient was treated with marginal mandibulectomy and immediate rehabilitation with osseointegrated implants; a hybrid prosthesis was fabricated a short time thereafter. This treatment plan demonstrated its utility and efficiency in this case. An approach with fewer surgeries and OMF rehabilitation needs be considered in all cases.

Does the Length of Dental Implants Inserted in Areas of Inferior Alveolar Nerve Lateralization Interfere on Mandibular Resistance to Fracture?

The aim of this study was to compare, in vitro, the mechanical resistance to vertical displacement of the mandible after osteotomy for lateralization of the inferior alveolar nerve and installation of dental implants. One hundred eighty polyurethane mandibles were equally divided into 6 groups: G1-intact hemi-mandibles (control group), G2-hemi-mandibles after osteotomy for lateralization of the inferior alveolar nerve, G3-hemi-mandibles with installation of 3 bicortical dental implants (3.75 × 13 mm), G4-hemi-mandibles with installation of 3 dental implants that did not reach the basal cortical bone (3.75 × 11 mm), G5-hemi-mandibles after osteotomy for lateralization of the inferior alveolar nerve and installation of 3 bicortical dental implants (3.75 × 13 mm) and G6-hemi-mandibles after osteotomy for lateralization of the inferior alveolar nerve and installation of 3 dental implants that did not reach the basal cortical bone (3.75 × 11 mm). The specimens were subjected to linear loading tests. The highest mean value of maximum load was found in G1 (412.36N ±â€Š11.99), followed by G2 (396.87N ±â€Š23.94), G3 (319.63N ±â€Š57.28), G4 (303.34N ±â€Š18.25), G5 (231.75N ±â€Š63.64) and G6 (228.13N ±â€Š20.75). Based on this data, it can be concluded that the bicorticalization (or not) of the implants was not a statistically significant risk factor for the vertical displacement of polyurethane hemi-mandibles.

Real Versus Virtual Position of Single Implants Installed in Premaxilla via Guided Surgery: A Proof of Concept Analyzing Positional Deviations.

The aim of this research letter was to report the results of a pilot study designed to compare the real and virtual position of implants placed using computer-guided flapless implant surgery for single restorations in the premaxilla. A total of 8 patients (2 men and 6 women) with a mean age of 40 years old (range: 32-73 years) had a total of 11 implants inserted using a tooth-supported stereolithographic guide. After implant placement, the positions (coronal, central, and apical) and angulation of the implants installed in relation to those planned were determined via the superposition of pre- and postoperative 3-dimensional models using Dental Slice software (Bioparts, Brasília, Brazil). The mean angular deviation was 2.54° ± 0.71°. The deviations found for the coronal, central, and apical positions were 1.3 ± 0.77 mm, 1.49 ± 0.58 mm, and 2.13 ± 1.32 mm, respectively.

Influence of implant drill materials on wear, deformation, and roughness after repeated drilling and sterilization.

PURPOSE: The aim of this study was to evaluate deformation, roughness, and mass loss of stainless steel, diamond-like carbon (DLC)-coated and zirconia drills after multiple osteotomies with sterilization procedures. MATERIALS AND METHODS: Drilling procedures were performed using stainless steel (G1), DLC-coated (G2), and zirconia (G3) drills. All groups were divided in subgroups 1, 2, 3, 4, and 5, corresponded to drills used 0, 10, 20, 30, and 40 times, respectively. RESULTS: No significant differences in mass and roughness were detected among all groups and subgroups. In SEM images, all groups revealed signs of wear while coating delamination was detected in G2. Drills from G1 displayed more irregular surface, whereas cutting edges were more regular in G3. CONCLUSION: Zirconia drills presented more regular surfaces whereas stainless steel drills revealed more severe signs of wear. Further studies must be performed to evaluate the putative influence of these findings in heat generation.

Comparison of sinusitis rate after sinus lift procedure and zygomatic implant surgery: a meta-analysis.

PURPOSE: To evaluate and compare the reported sinusitis occurrence after the sinus lift procedure and zygomatic implant placement. METHODS: This meta-analysis has been registered at PROSPERO. Studies were searched on six databases. Two authors screened titles and abstracts and fully analyzed the studies against the inclusion and exclusion criteria. The RoB 2.0 and the ROBINS-I tools were used to assess the quality and risk of bias of the included studies. The random-effects model was used for the meta-analysis. The prevalence of sinusitis was calculated based on the total of patients. Subgroup analysis was performed by sinus lift or zygomatic implant surgery technique. RESULTS: The search identified 2419 references. After applying the inclusion criteria, 18 sinus lift and 9 zygomatic implant placement studies were considered eligible. The pooled prevalence of sinusitis after sinus lift procedure was 1.11% (95% CI 0.30-2.28). The prevalence after zygomatic implant placement was 3.76% (95% CI 0.12-10.29). In the subgroup analysis, the lateral window approach showed a prevalence of sinusitis of 1.35% (95% CI 0.34-2.8), the transcrestal technique of 0.00% (95% CI 0.00-3.18), and the SALSA technique of 1.20% (95% CI 0.00-5.10). Regarding the techniques for zygomatic implant placement, the sinus slot technique showed a prevalence of 21.62% (95% CI 9.62-36.52) and the intrasinus technique of 4.36% (95% CI 0.33-11.08), and the prevalence after the extrasinus technique was 0.00% (95% CI 0.00-1.22). CONCLUSION: The sinusitis occurrence rate was higher after zygomatic implant placement than after sinus lift procedure and this occurrence was different depending on the used technique.

Effects of systemic ozone administration on the fresh extraction sockets healing: a histomorphometric and immunohistochemical study in rats.

OBJECTIVE: Studies have highlighted numerous benefits of ozone therapy in the field of medicine and dentistry, including its antimicrobial efficacy against various pathogenic microorganisms, its ability to modulate the immune system effectively, reduce inflammation, prevent hypoxia, and support tissue regeneration. However, its effects on dental extraction healing remain to be elucidated. .Therefore, this study aimed to evaluate the effects of systemically administered ozone (O3) at different doses in the healing of dental extraction sockets in rats. METHODOLOGY: To this end, 72 Wistar rats were randomly divided into four groups after extraction of the right upper central incisor: Group C - control, no systemic treatment; Group OZ0.3 - animals received a single dose of 0.3 mg/kg O3; Group OZ0.7 - a single dose of 0.7 mg/kg O3; and Group OZ1.0 - a single dose of 1.0 mg/kg O3, intraperitoneally. In total, six animals from each group were euthanized at 7, 14, and 21 days after the commencement of treatment. Bone samples were harvested and further analyzed by descriptive histology, histomorphometry, and immunohistochemistry for osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) protein expression. RESULTS: All applied doses of O3 were shown to increase the percentage of bone tissue (PBT) after 21 days compared to group C. After 14 days, the OZ0.7 and OZ1.0 groups showed significantly higher PBT when compared to group C. The OZ1.0 group presented the most beneficial results regarding PBT among groups, which denotes a dose-dependent response. OCN immunostaining was higher in all groups at 21 days. However, after seven and 14 days, the OZ1.0 group showed a significant increase in OCN immunostaining compared to C group. No differences in TRAP+ osteoclasts were found between groups and time points. CONCLUSION: Therefore, O3 therapy at higher doses might be beneficial for bone repair of the alveolar socket following tooth extraction.

Evaluation of deformation, mass loss, and roughness of different metal burs after osteotomy for osseointegrated implants.

PURPOSE: This study used bovine ribs to comparatively assess the deformation, roughness, and mass loss for 3 different types of surface treatments with burs, used in osteotomies, for the installation of osseointegrated implants. MATERIALS AND METHODS: The study used 25 bovine ribs and 3 types of helical burs (2.0 mm and 3.0 mm) for osteotomies during implant placement (a steel bur [G1], a bur with tungsten carbide film coating in a carbon matrix [G2], and a zirconia bur [G3]), which were subdivided into 5 subgroups: 1, 2, 3, 4, and 5, corresponding to 0, 10, 20, 30, and 40 perforations, respectively. The surface roughness (mean roughness [Ra], partial roughness, and maximum roughness) and mass (in grams) of all the burs were measured, and the burs were analyzed in a scanning electron microscope before and after use. Data were tabulated and statistically analyzed by use of the Kruskal-Wallis test, and when a statistically significant difference was found, the Dunn test was used. RESULTS: There was a loss of mass in all groups (G1, G2, and G3), and this loss was gradual, according to the number of perforations made (1, 2, 3, 4, and 5). However, this difference was not statistically significant (P < .05). Regarding the roughness, G3 presented an increase in Ra, partial roughness, and maximum roughness (P < .05) compared with G2 and an increase in Ra compared with G1. There was no statistically significant difference (P > .05) between G1 and G2. The scanning electron microscopy analysis found areas of deformation in all the 2.0-mm samples, with loss of substrates, and this characteristic was more frequent in G3. CONCLUSIONS: The 2.0-mm zirconia burs had a greater loss of substrates and abrasive wear in the cutting area. They also presented an increased roughness when compared with the steel and the tungsten carbide coating film in carbon matrix. There was no statistically significant difference (P < .05) between G1 and G2 in any mechanical test carried out.

Evaluation of satisfaction of patients rehabilitated with zygomatic fixtures.

PURPOSE: The aim of this study was to evaluate the satisfaction of patients rehabilitated with zygomatic fixtures and prosthesis with immediate loading. MATERIALS AND METHODS: The study selected patients who were rehabilitated with zygomatic implants at the clinic of the Latin American Institute for Dental Research and Education (ILAPEO. Curitiba-PR. Brasil) between 2005 and 2009. The patients were asked to answer a control-questionnaire during their follow-up visits. Data were collected regarding the level of patient satisfaction, reason for dissatisfaction, number of post-operative clinical sessions, and the type of complication. Sixteen patients were selected: 10 females and 6 males. RESULTS: Half of the patients were completely satisfied while the other half were satisfied with some complaints. The complaints were related to hygiene, esthetics, phonetics, and discomfort during chewing. Regarding the post-operative evaluation, 50% of the patients were attended due to the prosthesis (62.5%) and the implant (37.5%). CONCLUSIONS: The treatment with zygomatic fixtures is predictable and reliable. The patients were satisfied both with implants and prosthesis.

Full arch rehabilitation in patients with atrophic upper jaws with zygomatic implants: a systematic review.

BACKGROUND: The main objective of this systematic review was to present the outcomes of the treatment with zygomatic implants (ZIs) in the rehabilitations of atrophic upper jaw. FINDINGS: An electronic database search in PubMed, along with a manual search, taking into account language and study period, was performed by two observers; any type of clinical trial and series that included the use of ZIs was used. In the search strategy, the following search terms were used: zygom* AND dental (Implant OR implants) AND edentulous NOT (biomechanic* OR finite element) NOT cadaver. The search was limited to English language, full text, and humans. Literature reviews and clinical case reports were not considered. Forty-two articles published between March 2003 and April 2019 were included in this analysis. The cases of 1247 patients were recovered; these patients received 2919 ZIs. Fifty-two ZIs were removed during the follow-up time. The survival rate of these implants was 98.22%, with a minimum follow-up of 1 month and a maximum of 228 months. Different surgical techniques were used to place ZIs; however, the intrasinusal technique was the most used (23 studies). Post-surgical sinusitis was the most common complication reported in the studies (39 cases). CONCLUSIONS: Based on this review, ZIs were commonly used for rehabilitation of patients with atrophic upper jaw. The survival rates presented were high, and the surgical technique is dependent on the professional experience and the local anatomy. However, it needed additional clinical evidence on bone resorption, esthetic outcomes, and physiological characteristics.

Evaluation of Implants with Different Macrostructures in Type I Bone-Pre-Clinical Study in Rabbits.

The objective of this study was to assess the primary stability and the osseointegration process in implants with different macrostructures (Cylindrical vs. Hybrid Conical) in rabbit tibiae. Twenty-four (24) rabbits were used, divided into 3 experimental periods (2, 4 and 8 weeks) with 8 animals each. Each animal bilaterally received 2 implants from each group in the tibial metaphysis: Cylindrical Implant (CI) and Hybrid Conical Implant (HCI). All implants were assessed for insertion torque. After the experimental periods, one of the implants in each group was submitted to the removal counter-torque test and descriptive histological analysis while the other implant was used for microtomographic and histometric analysis (%Bone-Implant Contact). HCI implants showed higher insertion torque (32.93 ± 10.61 Ncm vs. 27.99 ± 7.80 Ncm) and higher % of bone-implant contact in the 8-week period (79.08 ± 11.31% vs. 59.72 ± 11.29%) than CI implants. However, CI implants showed higher values of removal counter-torque than HCI implants in the 8-week period (91.05 ± 9.32 Ncm vs. 68.62 ± 13.70 Ncm). There were no differences between groups regarding microtomographic data. It can be concluded that HCI implants showed greater insertion torque and bone-implant contact in relation to CI implants in the period of 8 weeks when installed in cortical bone of rabbits.

Oral Rehabilitation with Zygomatic Implants in a Patient with Cleft Palate.

Edentulous patients with an atrophic maxilla associated with lip-palate fissures have unpredictable results after undergoing grafting procedures. In situations where the atrophic maxilla does not adequately allow reconstruction, the use of zygomatic implants has been indicated, and probably these implants can be indicated for the rehabilitation of patients with lip-palate fissures. This case report describes the oral rehabilitation treatment of a patient with a lip-palate cleft treated with zygomatic implants and implant-supported fixed prosthesis with two years of follow-up. A 65-year-old female patient had a lip-palate cleft and previously underwent surgery to close the cleft. The patient had a severely atrophic maxilla and had difficulty adapting to a removable total prosthesis. Due to the small amount of bone remaining and extensive fibrous tissue in the palate region, a rehabilitation with conventional implants associated with zygomatic implants was chosen. Two zygomatic implants and a conventional implant were placed on the right side, and a zygomatic implant and conventional implant were placed on the left side; these implants were later activated by a protocol-type prosthesis. The zygomatic implants provided an adequate aesthetic and functional outcome of the prosthesis in a patient with cleft palate.

Effects of systemic ozone administration on the fresh extraction sockets healing: a histomorphometric and immunohistochemical study in rats

Abstract Studies have highlighted numerous benefits of ozone therapy in the field of medicine and dentistry, including its antimicrobial efficacy against various pathogenic microorganisms, its ability to modulate the immune system effectively, reduce inflammation, prevent hypoxia, and support tissue regeneration. However, its effects on dental extraction healing remain to be elucidated. Objective Therefore, this study aimed to evaluate the effects of systemically administered ozone (O3) at different doses in the healing of dental extraction sockets in rats. Methodology To this end, 72 Wistar rats were randomly divided into four groups after extraction of the right upper central incisor: Group C - control, no systemic treatment; Group OZ0.3 - animals received a single dose of 0.3 mg/kg O3; Group OZ0.7 - a single dose of 0.7 mg/kg O3; and Group OZ1.0 - a single dose of 1.0 mg/kg O3, intraperitoneally. In total, six animals from each group were euthanized at 7, 14, and 21 days after the commencement of treatment. Bone samples were harvested and further analyzed by descriptive histology, histomorphometry, and immunohistochemistry for osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) protein expression. Results All applied doses of O3 were shown to increase the percentage of bone tissue (PBT) after 21 days compared to group C. After 14 days, the OZ0.7 and OZ1.0 groups showed significantly higher PBT when compared to group C. The OZ1.0 group presented the most beneficial results regarding PBT among groups, which denotes a dose-dependent response. OCN immunostaining was higher in all groups at 21 days. However, after seven and 14 days, the OZ1.0 group showed a significant increase in OCN immunostaining compared to C group. No differences in TRAP+ osteoclasts were found between groups and time points. Conclusion Therefore, O3 therapy at higher doses might be beneficial for bone repair of the alveolar socket following tooth extraction.

Mandibular angle fractures treated with a single miniplate without postoperative maxillomandibular fixation: A retrospective evaluation of 50 patients.

OBJECTIVE: This retrospective study evaluated the use of a single miniplate for the treatment of mandibular angle fractures (MAF). METHODS: Fifty patients with 53 MAF were treated by open reduction and internal fixation with the use of a single miniplate and were analyzed in this study. RESULTS: Five patients with MAF had postoperative complications that required additional procedures. Three patients had postoperative infection, one patient complained of malocclusion in the first postoperative week, and one patient had miniplate exposure three months after surgery. Every additional procedure was performed in the office under local anesthesia without disruption of the initial fracture treatment. Postoperative maxillomandibular fixation (MMF) was performed in four patients. Treatment of MAF using a single miniplate was effective, with low morbidity and with low rates of postoperative complications. MAF can be treated without MMF, and stability is improved when long miniplates are used. CONCLUSIONS: The use of a single miniplate is therefore encouraged. However, postoperative MMF should be considered with the presence of little contact between bone segments, malocclusion, or extensive tooth loss.

Use of miniplates as a method for orthodontic anchorage: a case report.

INTRODUCTION:: Temporary anchorage devices (TADs) have been developed to be used as direct adjuncts in orthodontic treatment and have facilitated treatment of more complex orthodontic cases, including patients with dental impaction. OBJECTIVES:: This clinical case reports the applicability of TADs in the orthodontic treatment of a patient with impacted mandibular second molars. Surgical and orthodontic procedures related to the use of miniplates were also discussed in this study. CONCLUSIONS:: The use of temporary anchorage devices, such as miniplates, can be suggested as an alternative to treat patients with impacted mandibular second molars.

Simplifying the Treatment of Bone Atrophy in the Posterior Regions: Combination of Zygomatic and Wide-Short Implants-A Case Report with 2 Years of Follow-Up.

The rehabilitation of maxillary and mandibular bone atrophy represents one of the main challenges of modern oral implantology because it requires a variety of procedures, which not only differ technically, but also differ in their results. In the face of limitations such as deficiencies in the height and thickness of the alveolar structure, prosthetic rehabilitation has sought to avoid large bone reconstruction through bone grafting; this clinical behavior has become a treatment system based on evidence from clinical scientific research. In the treatment of atrophic maxilla, the use of zygomatic implants has been safely applied as a result of extreme technical rigor and mastery of this surgical skill. For cases of posterior mandibular atrophy, short implants with a large diameter and a combination of short and long implants have been recommended to improve biomechanical resistance. These surgical alternatives have demonstrated a success rate similar to that of oral rehabilitation with the placing of conventional implants, allowing the adoption of immediate loading protocol, a decrease in morbidity, simplification and speed of the treatment, and cost reduction. This case report presents complete oral rehabilitation in a patient with bilateral bone atrophy in the posterior regions of the maxilla and mandible with the goal of developing and increasing posterior occlusal stability during immediate loading.

Apicectomy with the Er:YAG laser or bur, followed by retrograde root filling with zinc oxide/eugenol or sealer 26.

OBJECTIVE: This study evaluated the influence of root resection, by means of the use of erbium:YAG laser in sealing two different materials, OZE and Sealer 26, in retrograde obturations. BACKGROUND DATA: Few studies with sufficient data have been conducted in this area. METHODS: Forty uniradicular teeth were used. They were biomechanically prepared using the step-back technique and obturated using the lateral condensation technique. The teeth were divided into two groups of 20 teeth, one group using the erbium:YAG laser (350 mJ and 6 Hz) for the resection process and the other using the Zekrya Drill, in high rotation. Then, the retrograde cavities were prepared using a micro counter-angle with a number 2 spherical bur. After preparing the cavities, the teeth were impermeabilized and divided into two subgroups. One subgroup used the retrograde obturation technique with Sealer 26 cement, and the other subgroup used OZE. After completing the retrograde obturation, the teeth were immersed in 2% methylene blue for a 7-day period. Teeth were then removed from the dye, washed, scraped, and sectioned in the vestibule-lingual direction. RESULTS: The results were analyzed with the aid of a magnifying lens, and scores were attributed based on the magnitude of infiltration. The data were then submitted to statistical analysis. CONCLUSIONS: No statistical difference was noticed regarding the root resection methods; however, in comparing materials, Sealer 26 was statistically superior to OZE. In the subgroup comparison, a significant difference was noticed in the Laser and Sealer 26 and the Laser and OZE and bur and OZE.

Recombinant human bone morphogenetic protein 2 in augmentation procedures: case reports.

To successfully rehabilitate edentulous patients using endosseous implants, there must be enough available bone. Several techniques have been proposed for augmentation of sites with insufficient bone volume. Although autogenous bone has long been considered the gold standard for such procedures, the limited availability of graft material and a high morbidity rate are potential disadvantages of this type of graft. An alternative is to use recombinant human bone morphogenetic protein 2 (rhBMP-2), which is able to support bone regeneration in the oral environment. These cases demonstrate the applicability of rhBMP-2 in maxillary sinus elevation and augmentation procedures in the maxilla to enable dental implant placement. The use of rhBMP-2 in alveolar augmentation procedures had several clinical benefits for these patients.