Identification of the Pathway and Appropriate Use of Four Zygomatic Implants in the Atrophic Maxilla: A Cross-Sectional Study.

PURPOSE: This cross-sectional study aimed to identify and characterize the pathway for appropriate placement of four zygomatic implants in the severely atrophic maxilla and to group the anatomical variations of the osteotomy trajectory for anterior zygomatic implants. MATERIALS AND METHODS: CBCT images of patients presenting indications for the use of four zygomatic implants to withstand a maxillary rehabilitation were reviewed. Cross-sectional planes corresponding to the implant trajectories, designed according to a zygoma anatomy-guided approach for implants placed in the anterior and posterior maxilla, were assessed separately. The relationship of the implant osteotomy trajectory with the correlated residual alveolar bone, nasal and sinus cavities, maxillary wall, and zygomatic bone anatomies was established. RESULTS: The study population included 122 globally recruited patients, with 488 zygomatic implants, 244 of which had their starting point on the anterior incisor-canine area and 244 on the posterior premolar-molar area. The anatomy of the osteotomy path designed for the anterior implants ("A") was named and grouped into five assemblies from zygomatic anatomy-guided ZAGA A-0 to A-4, representing 2.9%, 4.5%, 19.7%, 55.7%, and 17.2% of the studied sites. Percentages for posterior implant ("P") trajectories of the osteotomy were grouped and named as ZAGA P-0 to P-4, representing 5.7%, 10.2%, 8.2%, 18.4%, and 57.4% of the sites, respectively. Approximately 70% of the population presented anatomical intra-individual differences. CONCLUSION: The trajectory of the zygomatic implant followed different anatomical pathways depending on its coronal point being anteriorly or posteriorly located, which justifies a new zygoma anatomy-guided approach classification for anteriorly placed zygomatic implants. Topographic characteristics of the anatomical structures that are cut by an anterior oblique plane joining the lateral incisor-canine area to the zygomatic bone, representing the planned anterior osteotomy path in a quadruple-zygoma indication, have not been previously reported. Adaptation of surgical procedures and implant sections/designs to individual patients' anatomical characteristics is essential to reduce early and long-term complications.

Metal Nanoparticles Released from Dental Implant Surfaces: Potential Contribution to Chronic Inflammation and Peri-Implant Bone Loss.

Peri-implantitis is an inflammatory disease affecting tissues surrounding dental implants. Although it represents a common complication of dental implant treatments, the underlying mechanisms have not yet been fully described. The aim of this study is to identify the role of titanium nanoparticles released form the implants on the chronic inflammation and bone lysis in the surrounding tissue. We analyzed the in vitro effect of titanium (Ti) particle exposure on mesenchymal stem cells (MSCs) and fibroblasts (FU), evaluating cell proliferation by MTT test and the generation of reactive oxygen species (ROS). Subsequently, in vivo analysis of peri-implant Ti particle distribution, histological, and molecular analyses were performed. Ti particles led to a time-dependent decrease in cell viability and increase in ROS production in both MSCs and FU. Tissue analyses revealed presence of oxidative stress, high extracellular and intracellular Ti levels and imbalanced bone turnover. High expression of ZFP467 and the presence of adipose-like tissue suggested dysregulation of the MSC population; alterations in vessel morphology were identified. The results suggest that Ti particles may induce the production of high ROS levels, recruiting abnormal quantity of neutrophils able to produce high level of metalloproteinase. This induces the degradation of collagen fibers. These events may influence MSC commitment, with an imbalance of bone regeneration.

On the search of the ideal barrier membrane for guided bone regeneration.

BACKGROUND: GBRs are essential procedures in implant dentistry and periodontology where barrier membranes play an important role by isolating soft tissue and allowing bone to grow. Not all membranes function the same way, as they differ from their origin and structure, it is important to understand how membranes behave and differ one from others in order to achieve a predictable treatment. MATERIAL AND METHODS: A systematic search on Medline by two independent reviewers was performed for articles published until July 2017 reporting the characteristics or properties of barrier membranes. The question that preceded the search was designed according to PICO rules. RESULTS: A total of 124 articles were initially identified from electronic searching. After abstract/full-text review, 21 were included for a systematic review. According to the extracted data and article analysis, barrier membranes should fulfill the following criteria in order to success: biocompatibility, space maintaining, occlusive function, easy - handling and a bioactivation friendly property. With the development of new biomaterials and surfaces, a great advance in this area is expected. CONCLUSIONS: It has been clearly described that biocompatibility is the most important requirement to take into account when choosing a membrane, but other factors such as space maintaining capacity, cell oclusiveness, easy handling and bioactivation friendly materials are the ones that will fulfill our necessities. Key words:Barrier membrane, guided bone regeneration, dental implantology, oral surgery, collagen membrane, biomaterial.

Influence of Partial O2 Pressure on the Adhesion, Proliferation, and Osteogenic Differentiation of Human Dental Pulp Stem Cells on ß-Tricalcium Phosphate Scaffold.

PURPOSE: To analyze, in vitro, the influence of O2 pressure on the adhesion, proliferation, and osteogenic differentiation of human dental pulp stem cells (DPSC) on ß-tricalcium phosphate (ß-TCP) scaffold. MATERIALS AND METHODS: DPSC, positive for the molecular markers CD133, Oct4, Nestin, Stro-1, and CD34, and negative for CD45, were isolated from extracted third molars. Experiments were started by seeding 200,000 cells on ß-TCP cultured under 3% or 21% O2 pressure. No osteogenic medium was used. Eight different cultures were performed at each time point under each O2 pressure condition. Cell adhesion, proliferation, and differentiation over the biomaterial were evaluated at 7, 13, 18, and 23 days of culture. Cell adhesion was determined by light microscopy, proliferation by DNA quantification, and osteogenic differentiation by alkaline phosphatase (ALP) activity analysis. RESULTS: DPSC adhered to ß-TCP with both O2 conditions. Cell proliferation was found from day 7 of culture. Higher values were recorded at 3% O2 in each time point. Statistically significant differences were recorded at 23 days of culture (P = .033). ALP activity was not detectable at 7 days. There was, however, an increase in ALP activity over time in both groups. At 13, 18, and 23 days of culture, higher ALP activity was recorded under 3% O2 pressure. Statistical differences were found at day 23 (P = .014). CONCLUSION: DPSC display capacity of adhering to ß-TCP under 3% or 21% O2 pressure conditions. Cell proliferation on ß-TCP phosphate is significantly higher at 3% than at 21% O2 pressure, the most frequently used O2 tension. ß-TCP can itself promote osteogenic differentiation of DPSC and is enhanced under 3% O2 compared with 21%.

Association Between Clinical and Microbiologic Cluster Profiles and Peri-implantitis.

PURPOSE: The correlation between associated local factors and peri-implantitis remains unknown. The aim of this study was to investigate the association between the clinical and microbiologic profiles and peri-implantitis to eventually categorize different groups of this disease. MATERIALS AND METHODS: Subjects with at least one implant presenting signs of peri-implantitis were selected. The clinical, radiographic, occlusal, and microbiologic profiles of these infected implants were collected. Cases were classified into five peri-implantitis groups according to potential disease-triggering factors: surgically, prosthetically, biomechanically, purely plaque-associated, and a combination of them. Generalized estimating equations models were used to study differences among the potential risk factors. Cluster analyses were applied to investigate the correlation between clinical and microbiologic profiles and diseased implant samples. RESULTS: Overall, 110 diseased and 121 healthy implants were included. The biomechanically associated group showed higher levels of microbiologic contamination inside the connection; however, the plaque-associated group had a higher level of microbial variety in the peri-implant sulcus. Cluster analyses demonstrated a significant ability to predict the associated factor of peri-implantitis. Moreover, radiographic marginal bone loss and implant width demonstrated the largest influence on the model. CONCLUSION: While peri-implantitis represents a plaque-induced inflammatory condition, certain local factors might be associated with this biologic complication, as they imply plaque retention. Therefore, disease classification could be further implemented with the associated surgical, prosthetic, and biomechanical factors to better target the etiology.

Plasma of Argon Cleaning Treatment on Implant Abutments in Periodontally Healthy Patients: Six Years Postloading Results of a Randomized Controlled Trial.

The aim of this randomized, match-paired, triple-blinded, controlled clinical trial was to assess the 6-year radiographic changes around customized platform-switched abutments placed according to the one abutment-one time concept, with and without plasma of argon cleaning treatment. A total of 20 periodontally healthy patients received one maxillary implant between the premolars. Immediately before stage 2 surgery and abutment connection, patients were randomly assigned to the control (cleaning protocol by steam) or test group (plasma of argon treatment). Periapical standardized digital radiographs were taken at the time of crown connection (T0) and at 12 (T1), 24 (T2), 48 (T4), 60 (T5), and 72 months (T6) after the final restoration delivery. Primary outcome measures were the success rates of the implants and prostheses and the occurrence of any technical and biologic complications during the follow-up period. Secondary outcome measures were peri-implant marginal bone level changes, bleeding on probing, and plaque score. Two patients (one in test and one in control group) dropped out at the last follow-up. Neither implant nor prosthetic complications were detected in the analyzed patients of both groups during the 6-year follow-up examinations. Radiographic analysis revealed a statistically significant higher mean bone loss in the control group than in the test group at T2 (0.4 ± 0.28 mm; P = .018), T4 (0.52 ± 0.63 mm; P = .037), T5 (0.61 ± 0.70 mm; P = .038), and T6 (0.71 ± 0.66 mm; P = .011), but not at T1 (P = .131). From baseline to the 6-year follow-up, intragroup comparisons showed an absence of statistically significant difference in the test group (P = .08). Conversely, significant differences were found in the control group (P = .01). All implants demonstrated successful periodontal parameters, with no significant differences between groups. The results of this present study indicate that contaminant and bacterial removal from abutments in two-stage implants using plasma of argon could represent a positive strategy to minimize peri-implant bone resorption and longitudinally stabilize esthetic outcomes.

Vertical Osseodistraction with a New Intraosseous Alveolar Distractor Prototype for Dental Implant Rehabilitation: A Pilot Study in Dogs.

PURPOSE: To evaluate in dogs a newly developed intraosseous alveolar distractor (Mozo-Grau Alveolar Distractor) for vertical bone augmentation to allow placement of dental implants. MATERIALS AND METHODS: Four dogs had their posterior teeth removed, and sockets were left to heal for 20 weeks. The right and left sides of the posterior mandibles were randomly allocated, according to a split-mouth design, to receive either two distractors, distracting a 32-mm-long bone segment, or two distractors supporting one bony segment 20 mm long and one 8 mm long. Each side of the jaw was treated by a different operator. Eight days after placement, distractors were activated with one complete turn (corresponding to 0.75 mm of vertical distraction) per day for 8 days, followed by a latency period of 10 weeks. Distractors were removed, and seven dental implants of two randomly allocated designs were placed in each dog. Implants were submerged for 2 months, and the dogs were sacrificed. Outcome measures were: success of the augmentation procedure (defined as a vertical gain of at least 5 mm of bone), any complications, implant failure, bone-to-implant contact (BIC), and peri-implant marginal bone level changes. RESULTS: One dog was withdrawn because of a mandible fracture. Eight complications occurred, and six osseodistractors were lost, but no implant failed. Only two segments in one dog achieved a vertical bone gain of at least 5 mm. The mean radiographic vertical bone gain was 2.28 mm, whereas the mean histologic vertical bone gain was 3.16 mm. Histologically, all the implants were osseointegrated. The mean BIC for implants placed in new distracted bone was 34.78% ± 11.60% and 35.66% ± 8.84% for those placed in native bone. The mean peri-implant marginal bone level loss was 0.56 ± 0.54 mm. CONCLUSION: It is possible to achieve vertical augmentation using intraosseous alveolar distractors to allow successful implantation of dental implants; however, the technique still requires surgical refinements and a dedicated training of the surgeons before being applied to humans.

Influence of different types of pulp treatment during isolation in the obtention of human dental pulp stem cells

BACKGROUND: Different methods have been used in order to isolate dental pulp stem cells. The aim of this study was to study the effect of different types of pulp treatment during isolation, under 3% O2 conditions, in the time needed and the efficacy for obtaining dental pulp stem cells. MATERIAL AND METHODS: One hundred and twenty dental pulps were used to isolate dental pulp stem cells treating the pulp tissue during isolation using 9 different methods, using digestive, disgregation, or mechanical agents, or combining them. The cells were positive for CD133, Oct4, Nestin, Stro-1, CD34 markers, and negative for the hematopoietic cell marker CD-45, thus confirming the presence of mesenchymal stem cells. The efficacy of dental pulp stem cells obtention and the minimum time needed to obtain such cells comparing the 9 different methods was analyzed. RESULTS: Dental pulp stem cells were obtained from 97 of the 120 pulps used in the study, i.e. 80.8% of the cases. They were obtained with all the methods used except with mechanical fragmentation of the pulp, where no enzymatic digestion was performed. The minimum time needed to isolate dental pulp stem cells was 8 hours, digesting with 2mg/ml EDTA for 10 minutes, 4mg/ml of type I collagenase, 4mg/ml of type II dispase for 40 minutes, 13ng/ ml of thermolysine for 40 minutes and sonicating the culture for one minute. CONCLUSIONS: Dental pulp stem cells were obtained in 97 cases from a series of 120 pulps. The time for obtaining dental pulp stem cells was reduced maximally, without compromising the obtention of the cells, by combining digestive, disgregation, and mechanical agents

Surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft

BACKGROUND: A coronally advanced flap with subepithelial connective tissue graft is the gold standard surgical treatment of gingival recessions, since it offers a higher probability of achieving complete root coverage compared with other techniques. However, optimum short- and middle-term clinical results have also been obtained with coronally advanced flaps alone. The aim of the present study was to evaluate the results obtained by the surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft. MATERIAL AND METHODS: The reduction of recession height was assessed, together with the gain in gingival attachment apical to the recession, and total reduction of recession, in a comparative study of two techniques. Twentytwo gingival recessions were operated upon: 13 in the control group (coronally advanced flap) and 9 in the test group (coronally advanced flap associated to subepithelial connective tissue graft). RESULTS: After 18 months, the mean reduction of recession height was 2.2 ± 0.8 mm in the control group and 2.3 ± 0.7 mm in the test group, with a mean gain in gingival attachment of 1.3 ± 0.9 mm and 2.3 ± 1.3 mm, respectively. In percentage terms, the mean reduction of recession height was 84.6 ± 19.6% in the control group and 81.7 ± 17.8% in the test group, with a mean gain in gingival attachment of 20.5 ± 37.4% and 184.4 ± 135.5%, respectively. CONCLUSIONS: Significant reduction of gingival recession was achieved with both techniques, though the mean gain in gingival attachment (in mm and as a %) was greater in test group

Clinical and microbiological findings in patients with peri-implantitis: a cross-sectional study.

OBJECTIVE: The aim of this study was to analyze clinical and microbiological characters in subjects and implants affected and not affected by peri-implantitis. Additionally, same features were analyzed also intra-individually, comparing healthy and diseased implants within the same subject. MATERIALS AND METHODS: A total of 534 patients who received at least 1 implant and coming to routine check-up or spontaneous visits at the University of Valencia were recruited. Clinical parameters including Bleeding on probing (BoP), Probing pocket depth (PPD), and Pi were screened. Samples for microbiological analysis were obtained from three locations: peri-implant sulci (PIS), inner parts of the implant connections (I), and gingival sulci of neighboring teeth (GS). Quantitative real-time PCR was performed for total counts of 10 microorganisms. RESULTS: A total of 534 patients with 1507 dental implants were analyzed. The prevalence of peri-implantitis was found 10.3% for patients and 7.3% for implants. Higher percentage of healthy periodontal subjects were found in the non-peri-implantitis group. The analysis within the 53 patients affected by peri-implantitis revealed that the implants affected by peri-implantitis presented a higher percentage of plaque, BoP, and number of implants presenting <2 mm attached gingiva. Additionally, more cemented crowns and implants inserted in bone-augmented sites were found among the diseased implants. The microbiologic analysis presented no relevant differences between the analysis at the peri-implant sulcus (PIS) and the connections inside the abutments surfaces (PI). The microbial composition at the neighboring teeth (GS) resembled the composition found at the PIS with a high frequency of Pg, Tf, Pi, PM, and Ec. CONCLUSIONS: The results of this study seem to indicate that inadequate oral hygiene and the presence of bleeding from the gingiva/mucosa in patients with dental implant were associated with an higher prevalence of peri-implantitis; moreover, in the patients affected by peri-implantitis, the lack of sufficient height keratinized mucosa (<2 mm) and bone regenerative procedures at implant level were also associated to higher prevalence of peri-implantitis as well.

Surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft.

BACKGROUND: A coronally advanced flap with subepithelial connective tissue graft is the gold standard surgical treatment of gingival recessions, since it offers a higher probability of achieving complete root coverage compared with other techniques. However, optimum short- and middle-term clinical results have also been obtained with coronally advanced flaps alone. The aim of the present study was to evaluate the results obtained by the surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft. MATERIAL AND METHODS: The reduction of recession height was assessed, together with the gain in gingival attachment apical to the recession, and total reduction of recession, in a comparative study of two techniques. Twenty-two gingival recessions were operated upon: 13 in the control group (coronally advanced flap) and 9 in the test group (coronally advanced flap associated to subepithelial connective tissue graft). RESULTS: After 18 months, the mean reduction of recession height was 2.2 ± 0.8 mm in the control group and 2.3 ± 0.7 mm in the test group, with a mean gain in gingival attachment of 1.3 ± 0.9 mm and 2.3 ± 1.3 mm, respectively. In percentage terms, the mean reduction of recession height was 84.6 ± 19.6% in the control group and 81.7 ± 17.8% in the test group, with a mean gain in gingival attachment of 20.5 ± 37.4% and 184.4 ± 135.5%, respectively. CONCLUSIONS: Significant reduction of gingival recession was achieved with both techniques, though the mean gain in gingival attachment (in mm and as a %) was greater in test group.

Immediate Versus Conventional Loading of Complete-Arch Implant-Supported Prostheses in Mandibles with Failing Dentition: A Patient-Centered Controlled Prospective Study.

PURPOSE: The aim of this study was to compare, from the patients' perspective, immediate and conventional loading of fixed complete-arch prostheses to rehabilitate mandibles with failing dentition. MATERIALS AND METHODS: This controlled, prospective, nonrandomized study included 36 consecutive patients: 18 treated with conventional loading (control) and 18 with immediate loading (test). Patient general satisfaction and specific satisfaction with esthetics, chewing, speaking, comfort, self-esteem, ease of cleaning, and treatment duration were evaluated using 10-cm visual analog scales before treatment and 3 and 12 months after treatment. Postoperative pain and swelling were monitored daily for 1 week. Statistical analysis was performed applying Mann-Whitney and Wilcoxon tests (α = .05). RESULTS: Between baseline and 3 months, satisfaction in the test group increased significantly with the exception of speech; in the control group, satisfaction increased significantly for esthetics and decreased significantly for speech, chewing, and comfort, but did not vary for general satisfaction or self-esteem. After 3 months, satisfaction was significantly higher in the test group with the exception of ease of cleaning. Between 3 and 12 months, satisfaction improved in both groups but more so in the control group, so that after 12 months there were no differences. The test group showed lower mean pain, which began after the third day postsurgery. Mean swelling and maximum pain/swelling did not show significant differences at any point. CONCLUSIONS: Patient satisfaction was reported as significantly higher with immediate loading. However, at the end of the observation periods, reported functional differences had disappeared. Significant differences were only noted for postoperative pain after the third day.

Immediate versus conventional loading with fixed full-arch prostheses in mandibles with failing dentition: a prospective controlled study.

PURPOSE: To compare immediate and conventional loading protocols for fixed full-arch mandibular prostheses supported by immediate and nonimmediate implants. MATERIALS AND METHODS: A prospective controlled nonrandomized study with 12 months of follow-up included patients requiring fixed full-arch rehabilitations supported by immediate and nonimmediate implants. Eighteen patients were treated with conventional loading (control group), and 18 were treated with immediate loading (test group). Each patient received four to six implants; implants with insertion torque < 35 Ncm were excluded from the study and loaded conventionally. The following variables were assessed: implant success, biologic and prosthetic complications, success of the immediately loaded provisional prostheses, and marginal bone loss. Statistical analysis was performed with nonparametric tests (chi-square, Mann-Whitney, Kruskal-Wallis) with an alpha value of .05. RESULTS: Thirty-six patients consecutively enrolled in the study. Two control group patients failing to attend control visits and 12 implants that did not achieve an insertion torque of 35 Ncm were excluded. The final sample consisted of 34 patients and 183 implants (98 test and 85 control implants). Implant success rates were 99.0% (test) and 97.6% (control). Within the test group, success rates for immediate and nonimmediate implants were 100% and 97.6%, respectively. Differences were not statistically significant. All immediately loaded prostheses were successful. Five provisional fixed prostheses presented with loosened screws; all control group patients reported discomfort with the provisional denture. Average bone loss was 0.71 mm (standard deviation 0.25 mm) in the test group and 0.60 mm (standard deviation 0.28 mm) in the control group. CONCLUSION: No significant differences were seen in implant success and peri-implant marginal bone loss between immediate and conventional loading of mandibular fixed full-arch prostheses supported by immediate and nonimmediate implants. Biologic and prosthetic complications were rare, and all immediately loaded provisional fixed prostheses performed successfully.

Activation of p38, p21, and NRF-2 mediates decreased proliferation of human dental pulp stem cells cultured under 21% O2.

High rates of stem cell proliferation are important in regenerative medicine and in stem cell banking for clinical use. Ambient oxygen tensions (21% O2) are normally used for in vitro culture, but physiological levels in vivo range between 3% and 6% O2. We compared proliferation of human dental pulp stem cells (hDPSCs) cultured under 21% versus 3% O2. The rate of hDPSC proliferation is significantly lower at 21% O2 compared to physiological oxygen levels due to enhanced oxidative stress. Under 21% O2, increased p38 phosphorylation led to activation of p21. Increased generation of reactive oxygen species and p21 led to activation of the NRF-2 signaling pathway. The upregulation of NRF-2 antioxidant defense genes under 21% O2 may interact with cell-cycle-related proteins involved in regulating cell proliferation. Activation of p38/p21/NRF-2 in hDPSCs cultured under ambient oxygen tension inhibits stem cell proliferation and upregulates NRF-2 antioxidant defenses.

Patient-reported outcomes of immediate versus conventional loading with fixed full-arch prostheses in the maxilla: a nonrandomized controlled prospective study.

PURPOSE: To compare patient satisfaction and postoperative pain and swelling for immediate versus conventional loading in partially edentulous patients requiring extraction of the remaining maxillary dentition and rehabilitation with fixed full-arch prostheses. MATERIALS AND METHODS: This prospective, controlled, nonrandomized study with 12-month follow-up included 30 consecutive patients scheduled for fixed full-arch implant-supported maxillary rehabilitation. Fifteen patients were treated with conventional loading (control group) and the next 15 with immediate loading (test group). Ten-centimeter visual analog scales were used as assessment tools. Patient overall satisfaction and specific satisfaction with esthetics, chewing, speaking, comfort, self-esteem, ease of cleaning, and treatment duration were assessed preoperatively and at 3 and 12 months postoperatively. Postoperative pain and swelling levels were recorded daily during the first week. Statistical analysis was performed using Mann-Whitney and Wilcoxon rank sum tests, α = .05. RESULTS: One test group patient was excluded, so the final sample included 29 patients. Between baseline and 3 months, in the test group general satisfaction and all specific satisfactions increased significantly with the exception of speech; in the control group overall satisfaction and self-esteem did not change, satisfaction with esthetics increased significantly, and satisfaction with speech, chewing, and comfort decreased significantly. After 12 months, satisfaction was significantly higher in the test group with the exception of ease of cleaning. Between 3 and 12 months, satisfaction improved in both groups but to a greater degree in the control group. After 12 months, there were no differences in satisfaction. No differences were found in either mean postoperative pain/swelling or maximum pain/swelling at the studied time points. CONCLUSIONS: Patient satisfaction for immediate loading was significantly higher than for conventional loading during the osseointegration period. After 12 months, when final prosthetic rehabilitations had been in function for some time, differences had disappeared. No differences were found between loading protocols in postoperative pain or swelling.

Correcting loss of a papilla following orthodontic space opening (Atherton´s patch) through implant supported rehabilitation. A case report.

The objective of this case report is to describe a surgical and prosthetic technique to create a lost papilla following orthodontic space opening (Atherton´s patch) through implant supported rehabilitation. A switching platform implant was used to replace a left maxillary canine in a unitary interdental edentulous ridge with Atherton´s patch in the distal area of the upper lateral left incisor. The radiographic study revealed correct level of the interproximal bone of the adjacent teeth. A mucoperiosteal flap with crest incision and sulcular extension to the adjacent teeth was made. Special attention was paid to correct position of the implant and the distance (≥ 1.5 mm) between the platform and the roots of the adjacent teeth. A submerged technique was used. Tissue modeling through provisional crown was performed in order to create an ideal emergence profile with total papilla fill recorded at the Atherton´s patch area. Final screw retained CAD-CAM zirconia structure was place. Final follow up was performed 2 years after provisional crown placement, and total fill of both papilla, including at Atherton´s patch area, was recorded. Key words:Atherton´s patch, papilla, switching platform, implant and orthodontics, esthetic score.

Piezoelectric vs. conventional drilling in implant site preparation: pilot controlled randomized clinical trial with crossover design.

OBJECTIVE: To compare implant stability throughout osseointegration, peri-implant marginal bone loss, and success rates of implants placed with conventional and mixed drilling/piezoelectric osteotomy. MATERIALS AND METHODS: A pilot randomized-controlled trial was performed on 15 patients. Each patient received two implants in the mandibular molar region. All sites were prepared with conventionally up to the 2.8 mm wide drill. Osteotomies were randomly finalized with a 3 mm diameter drill (control group) or with two consecutive ultrasonic tips (2.8 mm and 3 mm wide, respectively) (test group). Resonance frequency analysis measurements were taken at implant placement and after 1, 3, 8, and 12 weeks. Peri-implant marginal bone loss 12 months after loading was calculated using periapical radiographs. Wilcoxon test for related samples was used to study differences in implant stability and in peri-implant marginal bone loss between the two groups. RESULTS: Twenty-nine of 30 implants osseointegrated successfully (one failure in the control group). Stability was significantly higher in the test group at the 8th week assessment; differences were non-significant at all other time-points. Longitudinally, differences were observed between the patterns of implant stability changes: in the test group stability increased more progressively, while in the control group an abrupt change occurred between the 8th and 12th weeks assessments. No difference was found in peri-implant marginal bone loss between the groups. All 29 implants were functionally successful at the 15-month visit. CONCLUSIONS: Within the limit of this pilot study (small sample size, short follow-up), data suggested that implant stability might develop slightly faster when implant site osteotomy is performed with a mixed drilling/ultrasonic technique.

Radiofrequency treatment of cervicogenic headache

Objectives: In the clinical management of facial pain, a possible cervical origin must be considered. A clinical exploration is therefore essential. The disorder originates in the intimate connections between the cranial portion of the spinal cord and the trigeminal system. Although solid evidence supporting the use of radiofrequency (RF) treatment is lacking, it remains one of the management options to be taken into account. The present study evaluates the efficacy of RF in application to cervicogenic headache. Study design: We present three cases of severe facial pain arising from different cervical structures. Results: In two cases the pain originated in cervical roots C2 and C3, while in the third patient the trigger point was located at the level of the atlantoaxial joint. Pulsed RF was applied for 4 minutes at the dorsal ganglion of C2 and C3 in the first two cases, and for 8 minutes at intraarticular level in the third patient. The pain gradually subsided during the first month in all cases. The first two patients reported 70% improvement after one month, 60% improvement after 6 months, and 30-50% after one year, versus baseline. The third patient reported complete pain resolution lasting approximately 5 months, after which the pain reappeared with the same intensity as before. Conclusions: Radiofrequency is a satisfactory treatment option, affording adequate analgesia, though the effects are sometimes temporary (AU)