A novel nonsurgical therapy for peri-implantitis using focused pulsed electromagnetic field: A pilot randomized double-blind controlled clinical trial.

Pulsed electromagnetic field (PEMF) therapy modulates the immune response and is successfully used in orthopedics to treat osteoarthritis and improve bone regeneration. This may suggest that this treatment may consequently reduce peri-implant soft tissue inflammation and marginal bone loss. To compare clinical, radiographic, and immunological results following nonsurgical treatment for peri-implantitis with or without PEMF therapy. Patients with peri-implantitis were included: pocket probing depth (PPD) between 6 and 8 mm with bleeding on probing (BOP); crestal bone loss between 3 and 5 mm. A novel healing abutment that contained active (test) or inactive (control) PEMF was connected. PEMF was administered via the abutment at exposure ratio of 1/500-1/5000, intensity: 0.05-0.5 mT, frequency: 10-50 kHz for 30 days. Nonsurgical mechanical implant surface debridement was performed. Patients were examined at baseline, 1 and 3 months. Clinical assessment included: plaque index, BOP, PPD, recession, and bone crest level which was radiography measured. Samples of peri-implant crevicular fluid were taken to analyze interleukin-1ß (IL-1ß). Twenty-three patients (34 implants; 19 control, 15 test) were included. At the follow-up, mean crestal bone loss was lower in the test group at 1 and 3 months (2.48 mm vs. 3.73 mm, p < 0.05 and 2.39 vs. 3.37, p < 0.01). IL-1ß levels were also lower in the test group at 2 weeks (72.86 pg/mL vs. 111.7, p < 0.05). Within all the limitation of this preliminary study, the test group improved clinical parameters after a short-term period compared to the control group.

The influence of radio frequency-based toothbrush on the accumulation of calculus and periodontal health: A randomized double-blind controlled prospective study.

OBJECTIVES: The use of a toothbrush with radio frequency (RF) has shown to be of benefit regarding the reduction of plaque, calculus, and dental staining and improving teeth shade compared to conventional powered and manual toothbrushes. AIM: To evaluate the efficacy of the RF toothbrush in the reduction of calculus accumulation and its effect on periodontal parameters as well as subject satisfaction as compared to an identical sham-tooth brush. MATERIALS AND METHODS: Patients who are under a strict maintenance program were included. Patients were allocated to test (RF toothbrush) or control (sham) randomly and were examined at baseline, one and three months. Clinical photos were taken and a consequential calculus assessment via ImageJ software. Clinical assessment included the following: plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD), and recession (REC). Patient satisfaction was assessed via a questionnaire. RESULTS: Fifty-eight patients (29 control, 29 test) were included. At baseline mean PPD, BOP, PI, REC, and calculus accumulation were similar between the groups. Mean buccal calculus was lower in the test group at one month 4.0% versus 6.7%, p < .05. Calculus accumulation within the groups was lower in the test group at 1 and 3 months when compared to baseline at the buccal aspect (2.8% vs. 8.9%, p < .05% and 3.8% vs. 8.9%, p < .05) and lingual aspect (6.7% vs. 16.5%, p < .05% and 8.9% vs. 16.5%, p < .05). No statistically significant results were found regarding periodontal parameters PPD, BOP, PI, and REC. No difference was found between groups regarding patient satisfaction. CONCLUSION: RF seems to have an additive effect on preventing calculus accumulation on the buccal aspect of anterior mandibular teeth at 1 month. Nevertheless, at 3 months, no difference between the toothbrushes is seen regarding calculus formation and maintaining periodontal health (ClinicalTrials.gov, Identifier NCT04640857).

Revealing leukocyte populations in human peri-implantitis and periodontitis using flow cytometry.

OBJECTIVE: To identify, quantify, and characterize leukocyte populations in PI and periodontitis using flow cytometry. METHODS: Fresh biopsies from human PI and periodontitis lesions were processed to a single-cell suspension. The immune cell types were identified using flow cytometry. RESULTS: Twenty-one biopsies were obtained and analyzed corresponding to fourteen PI and seven periodontitis samples. Participants' average age was 63.95 ± 14.77 years without a significant difference between PI and periodontitis patients, the female/male ratio was 8/12, and mean PD was 8.5 ± 2.17. High similarity was found between periodontitis and PI in the main immune cell types. Out of the leukocytes, the PMN proportion was 40% in PI and 33% in periodontitis. T-cells 22% in PI and 18% in periodontitis. Similar proportions of B-cells 10% and macrophages 6% were found in PI and periodontitis. Dendritic and NK cells were found in low proportions (~ 1%) in PI and periodontitis. T-cell sub-analysis showed that CD4-positive were more prevalent than CD8-positive in both diseases (CD4/CD8 ratio of 1.2). CONCLUSION: With the use of flow cytometry analysis, the leukocyte populations in human peri-implantitis and periodontitis were classified. In PI and periodontitis, we identified similar proportions of specific (CD4/CD8) and innate (dendritic and NK) immune cells. These results corroborate previous histological studies. CLINICAL RELEVANCE: Flow cytometry analysis can be used to identify and quantify immune cells in PI and periodontitis, including sub-classification of T cells (CD4/8) as well as detection of cells that require multiple markers for identification (such as dendritic cells).

Comparing Operators and Imaging Techniques When Performing Trans-Crestal Sinus Augmentation: A Pilot Study.

The aim of this article was to compare baseline residual ridge height using Cone-beam Computed Tomography (CBCT) and panoramic radiographs. A secondary aim was to examine the magnitude of vertical bone gain 6 months after trans-crestal sinus augmentation and compare it between operators. Thirty patients, who underwent trans-crestal sinus augmentation simultaneously with dental implant placement, were included in this retrospective analysis. Surgeries were done by 2 experienced surgeons (EM and EG) using the same surgical protocol and materials. Preoperative residual ridge height was measured on panoramic and CBCT images. The final bone height and the magnitude of the vertical augmentation were measured on panoramic X ray taken 6 months after surgery. Mean residual ridge height measured preoperatively using CBCT was 6.07 ± 1.38 mm, whereas these same measurements on the panoramic radiographs yielded similar results (6.08 ± 1.43 mm), which were statistically insignificant (P = .535). Postoperative healing was uneventful in all cases. All 30 implants were successfully osseointegrated at 6 months. The mean overall final bone height was 12.87 ± 1.39 mm (12.61 ± 1.21 and 13.39 ± 1.63 mm for operators EM and EG, respectively; P = .19). Likewise, mean postoperative bone height gain was 6.78 ± 1.57 mm, which was 6.68 ± 1.32 and 6.99 ± 2.06 mm for operators EM and EG, respectively (P = .66). A moderate positive correlation was found between residual bone height and final bone height (r = 0.43, P = .002). A moderate negative correlation was found between residual bone height and augmented bone height (r = -0.53, P = .002). Sinus augmentation performed trans-crestally produce consistent results with minimal interoperator differences between experienced clinicians. Both CBCT and panoramic radiographs produced similar assessment of the preoperative residual bone height.

Palatal soft tissue thickness around dental implants and natural teeth in health and disease: A cross sectional study.

BACKGROUND: Previous studies focused on the influence of buccal mucosa thickness on peri-implant bone loss and inflammation, with inconclusive results. We observed substantially thicker palatal mucosal tissues at peri-implantitis sites. Therefore, we hypothesize that thick palatal peri-implant mucosa may be associated with deeper pockets and disease severity. PURPOSE: To compare the thickness of the palatal tissue between natural teeth and implants in periodontal health and disease. METHODS: Adult, non-smoker, healthy patients who visited our department for periodontal examination or treatment with restored implants in the posterior maxilla were recruited. Probing depth (PD), plaque index (PI), gingival index (GI) and radiographic measurements were recorded around implant and the contralateral tooth. Palatal tissue thickness was measured using a 30G needle that was inserted perpendicular into the mucosa at the bottom of the periodontal/peri-implant pocket and 3 mm coronally. Differences in the palatal tissue thickness between teeth and implants (in the same patient) was performed using t-test; as well as between peri-implantitis and non-peri-implantitis sites (among patients). RESULTS: Sixty patients were included. Thirty-four implants were diagnosed with peri-implantitis and 26 healthy/mucositis implants with corresponding 24 healthy/gingivitis teeth and 36 teeth with attachment loss. Mean PD was higher around implants (4.47 ± 1.57 mm) than teeth (3.61 ± 1.23 mm, p = 0.001). The thickness of implants' palatal mucosa was higher than in teeth, at the base of the pocket and 3 mm coronally (4.58 ± 1.38 mm vs. 3.01 ± 1.11, p = 0.000; 3.58 ± 2.15 vs. 1.89 ± 1.11, p = 0.000, respectively). Mean palatal tissue thickness was 4.32 ± 2.35 mm for the peri-implantitis group while only 2.61 ± 1.39 in healthy implants, 3 mm coronal to the base of the pocket (p = 0.001). Palatal thickness at peri-implantitis sites was higher (4.32 ± 2.35) compared to periodontitis sites (2.23 ± 0.93), p = 0.000. Implant sites with palatal mucosa >4 mm (n = 32) had deeper mean pockets (5.58 ± 1.98) compared with thinner (≤4 mm) sites (n = 28) (4.48 ± 1.18, p = 0.018). CONCLUSION: Thicker palatal tissue around implants is associated with deeper palatal pockets. Thick palatal tissue was found around implants diagnosed with peri-implantitis.

Digital photometric analysis of gingival response to periodontal treatment.

OBJECTIVES: The color is a major factor in determining inflammation status in most gingival indices. Current indices have limitations mainly due to subjective nature. Digital color analysis can provide objective and accurate measurements. Thus, the present study aimed to assess by digital tool the gingival color in the different stages of an active periodontal treatment. METHODS: Forty patients (19 males and 21 females) diagnosed with periodontitis (stage III/ IV, grade C) and treated surgically were included in the study. Clinical data (probing depth, bleeding on probing, clinical attachment level, gingival index, and gingival recession) and photographs by digital single-lens-reflex (DSLR) camera were recorded before initial periodontal treatment, which included scaling and root surface debridement (T0); the same parameters were then re-evaluated 6-8 weeks (T1) and 3 months after periodontal surgery (regenerative/resective) (T2). Differences between clinical parameters were calculated. The color space defined by the International Commission on Illumination (CIELab) was used to analyze gingival color. RESULTS: In 56 periodontal surgical sites, 168 photographs were taken. The a*-value of the CIELab color system (higher a*- value translate to a stronger red color) was significantly reduced between T0 to T1 and further decreased at T2 (32.01, 29.28, and 27.45 respectively). Significant improvement in clinical parameters were found between T0 to T1 and T1 to T2. Sub-analysis of two distinct surgical interventions revealed that only regenerative procedure improved the a*-value, which was significantly correlated with pocket depth reduction. CONCLUSIONS: Photometric analysis can be used to assess gingival color change during periodontal treatment of patients with periodontitis. CLINICAL SIGNIFICANCE: Gingival inflammation is a major factor in periodontal assessment; nevertheless, all current gingival inflammation indices are partially subjective and only semi-quantitative. The digital photometric analysis may allow for accurate and objective gingival color assessment during periodontal treatment.

Histological and dimensional changes of the alveolar ridge following tooth extraction when using collagen matrix and collagen-embedded xenogenic bone substitute: A randomized clinical trial.

AIM: To assess the horizontal and vertical dimensional changes of the alveolar ridge when using a collagen matrix in combination with collagen embedded xenogenic bone substitute, in comparison with natural healing after tooth extraction. METHODS: Patients that required extraction in non-molars areas were included. Test group-15 sockets were treated with deproteinized bovine bone mineral containing 10% collagen (DBBM-C), covered by a procaine collagen membrane (CMXs). Control group-15 sockets left for spontaneous healing. We used a custom-made acrylic stent as a reference for alveolar ridge measurements. Six-month postoperative, a single implant was placed in the experimental site. A core biopsy was taken from the site, using a trephine bur. Histomorphometric analysis assessed bone area, connective tissue, bone marrow, and residual bone graft. RESULTS: Six months later, horizontal ridge width at -3 mm showed a significant (p < 0.05) reduction in both groups albeit smaller in the test group 1.19 ± 1.55 mm, compared with the control 2.27 ± 1.52 (p = 0.087). At -5 mm sub-crestally, statistically non-significant reduction was noted in both groups, 1.61 ± 1.53 and 1.96 ± 1.52 mm for the test and control groups, respectively (p = 0.542). Vertical changes were smaller in the test group (0.14 ± 1.84 mm) compared with control (0.98 ± 1.49 mm). Keratinized tissue (KT) width was 7.3 ± 2.13 and 7.5 ± 3.49 mm in the test and control groups, respectively. Newly formed bone occupied 33.79 ± 17.37% and 51.14 ± 23.04% in the test and control groups, respectively, (p = 0.11). Connective tissue volume was 33.74 ± 13.81% and 30.12 ± 18.32% in the test and control groups, respectively (p = 0.65). Bone marrow occupied 19.57 ± 10.26% and 18.74 ± 17.15% in the test and control groups, respectively (p = 0.91). Residual graft occupied 12.9 ± 9.88% in the test group. CONCLUSION: Alveolar ridge preservation using DBBM-C resulted in reductions of the vertical and horizontal dimensions albeit not reaching statistical significance. The larger than anticipated standard deviation and smaller inter-group differences might account for this phenomenon.

Severe Complications Following Maxillary Sinus Augmentation Using Poly L-lactide-co-ε-caprolactone-Coated Bovine Bone: A Retrospective Study.

PURPOSE: To describe the postoperative complications following lateral wall sinus augmentation using (poly L-lactideco-ε-caprolactone; PLCL) and natural polysaccharides polymers-coated bovine bone (PBB). The secondary aims were to examine histologic findings and to propose complication management alternatives. MATERIALS AND METHODS: This retrospective study included 61 subjects who underwent 67 lateral wall sinus augmentation procedures using PBB in the standard protocol. In cases that presented complications, treatment included additional antibiotic therapy, implant removal, or sinus reentry and total removal of the grafting material. In three cases, biopsy specimens were taken from the sinuses, and histologic analyses were performed. RESULTS: The prevalence of postoperative complications was 32.8% (22 of 67 cases) in 18 of the patients (29.5%). The most prevalent symptoms were persistent pain (68.2%), swelling (63.6%), and oroantral fistula (54.5%). Radiographic signs appeared in 45.5% of the complications. A total of 24 implants failed; thus, an overall 80.3% survival rate was established at 19 months. The vast majority of complications (86.4%) were treated eventually with reentry surgery and revealed that the sinus was full with granulation tissue surrounding pieces of a nonossified rubber-like material. In cases where implants were placed, nonosseointegrated implants were surrounded by soft tissue. The sinus was cleaned thoroughly; the graft material remnants were removed together with inflamed parts of the sinus membrane, followed by chlorhexidine and saline lavages. In the biopsy specimens taken from the sinus cavity, there were no histologic features of new bone formation around the grafted material. CONCLUSION: Lateral wall maxillary sinus augmentation using PBB was associated with an acute sinus infection histologic appearance and with a 7-times-higher failure rate compared with previous reports. This serious adverse event suggests that PBB cannot be recommended for maxillary sinus augmentations.

A single application of chlorhexidine gel reduces gingival inflammation and interleukin 1-ß following one-stage implant placement: A randomized controlled study.

BACKGROUND: Chlorhexidine (CHX) is a broad-spectrum antimicrobial agent commonly used in medicine. Application of (CHX) during abutment connection reduced the bacterial load at the implant-abutment interface. We hypothesize this treatment may consequently reduce peri-implant soft tissue inflammation and marginal bone loss. PURPOSE: To evaluate the effect of a single application of CHX gel inside the dental implant internal hexagon on peri-implant tissue. METHODS: Forty patients were recruited to this randomized, double-blinded, clinical trial. At the time of implant installation, a 4-mm healing abutment was connected to the implant. In the test group, chlorhexidine gel 1% was applied inside the implant hex, whereas control implants did not receive any gel. Clinical and radiographic measurements included soft tissue recession (REC), plaque index (PI), gingival index (GI), plaque index (PI), keratinized mucosa width (KM), probing depth (PD), and a peri-apical parallel x-ray. Peri-implant crevicular fluid (PICF) was collected for cytokine analysis. t-Test was used to compare changes from baseline to 3 months. Mann-Whitney U test and t test were used to compare test and control groups. RESULTS: Twenty patients in the test group and 17 in the control group completed the study. One implant in the control group failed to osteointegrate. There were no significant differences between the control and test groups for REC changes, bone loss, and PD. GI was significantly lower in the test group after 1 week (1.79 ± 0.24 vs 0.75 ± 0.18, respectively) and 3 months (1.18 ± 0.21 vs 0.25 ± 0.12, respectively) although PI was equal. At 3 months, interleukin 1-ß (IL1-ß) was higher in the control group (p < 0.01) and a positive correlation was found between GI and IL1-ß (rs  = 0.60424, p = 0.00032). CONCLUSIONS: Application of chlorhexidine gel reduced inflammation and IL1-ß levels in the peri-implant soft tissue.

Thermal Changes at the One-Piece Implant Surface During the Setting of Two Autopolymerized Acrylic Resins.

PURPOSE: To compare the temperature changes during the setting process of two provisional crown materials, polymethyl methacrylate (PMMA)-based acrylic resin (Ac) and bis-acryl composite resin (Co), at the first thread surface of one-piece implants. MATERIALS AND METHODS: Twenty-two 3.3-mm-diameter one-piece implants were divided into two groups according to the provisional restoration material. Implants were mounted on a Plexiglas apparatus. A K-type thermocouple was fixed at the most coronal thread. Baseline (Bl Temp) and maximal (Max Temp) temperatures of both groups were recorded during the curing process. Total heat flux (THF) at the implant surface and thermal amplitude (Temp-Amp) were calculated. Differences between groups were compared using a t test for unpaired observations. RESULTS: Upon curing, a statistically significant increase in the Max Temp from the Bl Temp was detected in both groups, with a greater increase in the Ac compared with the Co group. The Temp-Amp and the THF were two times greater in the Ac group than the Co group. CONCLUSION: Significant heat is produced during the polymerization of PMMA-based resin and bis-acryl composite resin provisional crowns in one-piece implants. To decrease the risk of thermal challenge at the implant cervical aspect associated with restoration of immediately loaded implants, bis-acryl composite resin should be used.

Supportive periodontal therapy affects dental implants probing pocket depth, bleeding on probing, and bone level: a 4- to 8-year follow-up study.

Objective: To evaluate implant and patient characteristics 4 to 8 years after implant installation in a study involving immediate fixed restoration of dental implants. Method and materials: The study was a follow-up of treated generalized chronic periodontitis patients who received immediate restorations on dental implants as part of a previous study. The patients were examined clinically and radiographically at implant placement, 6 months, 1 year, and 4 to 8 years later. Supportive periodontal therapy (SPT), teeth and implant probing pocket depth (TPPD and IPPD), bleeding on probing (BOP [teeth, TBOP; implant, IBOP]), and bone level (BL) measurements around implants were documented. Cases were divided into three groups according to annual SPT rate: 0.00 to 0.99/year (SPT0), 1.00 to 1.99/year (SPT1), 2.00 or more/year (SPT2). Results: Twelve patients, with 26 implants and 242 teeth, were included. The mean ±â€¯standard deviation follow-up period was 6.08 ±â€¯1.25 years (range 4.04 to 7.94 years). All implants in the follow-up group were osseointegrated and survived during the follow-up period. The mean number of SPT appointments was 6.17 ±â€¯5.65. A weak negative correlation was found between SPT rate and ΔTPPD (-0.24, P = .0005), whereas a strong negative correlation was found between SPT rate and ΔIPPD (-0.76, P = .0005). Negative correlations were found between SPT rate and ∆TBOP (-0.20, P = .003), and between SPT rate and ∆IBOP (-0.5, P = .009). A moderate correlation was found between SPT rate and ΔBL (0.46, P = .02). Conclusion: SPT has a significant positive effect on PPD, BOP, and on implant BLs in long-term follow-up and should be an essential part of implant therapy.

Clinical and Patient-Related Outcomes of a Tapered Implant System With Switched Platform Conical Abutments: A Private Practice Field Trial.

The aim of this prospective cohort observational field trial was to examine 1-year survival and success rates of a recently introduced tapered implant system with switched platform conical abutments and to evaluate patient related outcomes of therapy. Partially edentulous patients aged between 18 and 75 years, with available bone height for dental implants ≥10 mm desiring to restore the missing tooth/teeth with implant supported restoration, were recruited by 7 periodontists in their respective private practices. Dental implants were installed according to standard implant therapy protocol. Three to 6 months postoperatively, after evaluating interim implant success, implants were restored by the referring dentists. Patient, Ramfjord teeth, and implant data, including baseline and 1-year postoperative, were collected. A total of 60 patients were recruited and received 117 implants. Complete 1-year clinical and radiographic data were available for 83 and 65 implants, respectively. Two implants failed during the first year, resulting in a 1-year survival rate of 98.3%. Mean implant probing pocket depth was 2.29 ± 0.84 mm. Mean radiographic bone distance from implant's shoulder at the mesial and distal sites at 1 year was 0.66 ± 0.5 and 0.79 ± 0.64mm, respectively, resulting in a success rate of 95.4%. Patient subjective evaluation of therapy exhibited a median pain experience of 1 and median esthetics, function, and general satisfaction evaluation of 10 on a scale of 1 to 10. The tapered conical connection dental implant system, used in private dental practices, shows good 1-year survival and success rates that are similar to other implant systems on the market.

Invasive cervical resorption following orthodontic treatment: Two cases involving the same patient.

Invasive cervical resorption (ICR), a destructive form of external root resorption, is characterized by invasion of the fibrovascular tissue. This phenomenon is very rare and appears in 0.02% of the general population where the leading factors are orthodontics in addition to trauma, restorations, and bleaching. Heavy orthodontic force may increase the incidence to 1%. One of the main concerns regarding ICR is that it is often misdiagnosed with conventional diagnostic tools. In recent decades, a cone beam computed tomography (CBCT) imaging technique has become more common and can lead to a more accurate diagnosis and treatment plan. This case report describes a possible association between orthodontic treatment and ICR of a 14-year-old male, 18 months post orthodontic treatment. ICR in the mandibular right canine was diagnosed and verified by CBCT, and underwent combined endodontic-periodontal treatment. However, after orthodontic forced eruption was performed on this tooth to improve the bone defect, ICR was diagnosed on the mandibular right second premolar. The possible association between orthodontic treatment and ICR is discussed, as ICR was noted following orthodontic treatment on both occasions. This case report stresses the importance of ICR early detection by close attention to periodic radiographic checkups during orthodontic treatment. The use of modern diagnostic tools is highly recommended in suspicious cases. CONCLUSION: A case is described in which the patient underwent two types of orthodontic treatment in the mandible at different time periods and developed ICR in two different teeth.

Plaque score change as an indicator for periimplant health in periodontal patients with immediately restored dental implants.

BACKGROUND: Patients with a history of periodontitis might have a higher risk for implant failure as compared with periodontally healthy subjects. The aim of the present study was to look into this risk factor by examining the association between plaque scores, probing depths (PD), and bleeding on probing (BOP) around teeth and immediately restored dental implants up to 1 year after implant surgery. METHODS: Patients with partial edentulism, diagnosed with and previously treated for generalized chronic periodontitis, received dental implants, abutments, and cemented provisional prostheses up to 72 hours after implant surgery. Plaque scores, PD, and BOP were recorded and evaluated 6 and 12 months postsurgery. RESULTS: Plaque scores deteriorated slightly around teeth and improved around implants. No significant change was observed in the distribution of PD around teeth. The proportion of shallow pockets increased around implants. Improvement in plaque scores was associated with a stable/reduced PD, whereas deterioration in plaque scores was associated with increased PD around implants and teeth. CONCLUSIONS: A direct relationship was found between plaque score improvement and stable/reduced PD. Therefore, partially edentulous patients with a history of periodontitis should be encouraged to improve their plaque scores to maintain shallower pockets around implants.

Novel implant design improves implant survival in multirooted extraction sites: a preclinical pilot study.

BACKGROUND: The primary aim is to evaluate clinical, radiographic, and histologic parameters of novel implants with "three roots" design that were inserted into fresh multirooted extraction sockets. A secondary aim is to compare this new implant to standard root-form dental implants. METHODS: Immediate implantation of novel or standard design 6 × 6-mm implants was performed bilaterally into multirooted sockets in mandibles of mini-pigs. Twelve weeks later, clinical, radiographic, stability, histomorphometric, and microcomputed tomography (micro-CT) analyses were performed. RESULTS: Survival rates were significantly higher in the test implants compared with control (92.8% versus 33.3%, respectively; P <0.001). Bone loss was greater in the control compared with the test by sounding (mean 3.42 ± 0.68 versus 1.96 ± 0.34 mm) and radiography (mean 3.35 ± 0.62 versus 2.27 ± 0.33 mm). Histologic and micro-CT analyses demonstrated bone fill in the inner part of the test implants. Moreover, bone-to-implant contact was higher in the test implants (55.50% ± 3.68% versus 42.47% ± 9.89%). Contrary to the clinical, radiographic, and histomorphometric results, resonance frequency analysis measurements were greater in the control group (77.74 ± 3.21 implant stability quotient [ISQ]) compared with the test group (31.09 ± 0.28 ISQ), P = 0.008. CONCLUSIONS: The novel design implants resulted in significantly greater survival rate in multirooted extraction sites. Further studies will be required to validate these findings.

Primary stability following abutment preparation of one-piece dental implants.

PURPOSE: One-piece dental implants are commonly used for the immediate restoration of missing teeth. In most cases, the clinician has to prepare the abutment intraorally to ensure a proper emergence profile and abutment angulation. However, this procedure might impair primary stability and thus potentially compromise osseointegration. The aim of this study was to determine the effect of abutment preparation on the primary stability of a one-piece implant system (UNO MIS). MATERIALS AND METHODS: Implant stability was assessed by resonance frequency analysis with a novel custom-made external fixation device, validated previously, developed specifically for resonance frequency measurements of this implant. Thirty 3 × 13-mm implants were inserted in porcine jawbone with insertion torque of 15 Ncm (group A, 15 implants) or 30 Ncm (group B, 15 implants). Abutments were prepared by reducing the facial aspect of the implant abutment with a high-speed dental turbine (400,000 rpm) equipped with a medium-roughness diamond bur. Implant stability quotients (ISQs) were measured before and after abutment preparation. RESULTS: Mean ISQs measured in group A and group B before abutment preparation were very similar (58.2 ± 1.4 and 57.4 ± 0.9, respectively; P > .05). Following abutment preparation, three implants in group A lost primary stability. The mean ISQ value in group A was reduced from 58.2 ± 1.4 to 54.9 ± 7.9 following abutment preparation (P < .05). The mean ISQ in group B was not affected by abutment preparation (57.4 ± 0.9 versus 57.3 ± 1.0; P > .05). CONCLUSIONS: Abutment preparation of a one-piece dental implant inserted with low insertion torque might impair implant primary stability.

Immediate restoration of delayed placement of dental implants in patients with treated periodontal disease: 1-year results.

PURPOSE: To evaluate implant and patient characteristics in a prospective clinical study involving immediate fixed restoration of delayed placement of dental implants. MATERIALS AND METHODS: Patients diagnosed with generalized chronic periodontitis and previously treated were accepted into the study when they expressed a wish to receive immediate restoration of dental implants. Treatment planning and implant placement were computer assisted, using computerized tomography, planning software, and a surgical template. Patients received abutments and cemented provisional prostheses no later than 72 hours following implant surgery. Patients were followed at 2 and 4 weeks, and 3, 6, and 12 months. RESULTS: Eighteen patients were accepted and completed the study, ages ranged from 34 to 69 years (mean 54.5±8.5 years). Five patients (27.8%) were smokers (2.5 to 60 pack years). Fifty implants were placed, ranging between 1 to 8 implants per patient. Median implant length was 13 mm (range, 10 to 13 mm) and median implant diameter was 3.75 mm (range, 3.75 to 5 mm). Mean insertion torque was 43 NCm±6.2 SD (range 30 to 50 NCm). Mean implant stability quotient was 71±11 (range 37 to 85). One implant in a patient who smoked and three implants in another patient who smoked failed for a total of four failed implants. At 12 months, the overall survival rate was 92% (100% and 73% among nonsmokers and smokers, respectively). CONCLUSIONS: The survival of immediately restored dental implants in periodontally treated patients is greater than 90%. Smokers with a past history of chronic periodontitis seem to have a lower implant survival rate.

A novel device for resonance frequency assessment of one-piece implants.

PURPOSE: Immediate loading and/or restoration of dental implants requires the assessment of implant stability, which is best performed by resonance frequency analysis (RFA) prior to loading. One-piece dental implants are usually used for immediate loading, but there is currently no available reliable method to assess the primary stability of one-piece dental implants. Therefore, this study sought to validate a novel device designed for RFA measurements of one-piece implants. MATERIAL AND METHODS: Thirty (3.75 x 13 mm) internal-hex implants (Seven, MIS) were divided into two groups; 15 were placed in an acrylic glass block and 15 were placed in fresh porcine jawbone using 30 N/cm2 of insertion torque. Implant stability quotient (ISQ) values were measured using the Osstell Mentor device; then, a new external fixation device was attached to the implant abutment with a 10-mm arm extending from the implant to an internal-hex ring at its proximal end. ISQ values were measured at the implant's internal hex and at the internal hex of the device, and the damping ratio was calculated. The measurements were repeated with 15 (3 x 13 mm) one-piece implants (UNO, MIS) attached to the same device. RESULTS: The damping ratio between the implant and the proximal device was 23.6% ± 4% in acrylic glass (50.1 ± 1.7 ISQ and 38.2 ± 1.8 ISQ, respectively) and 23.1% ± 3% in porcine bone (74.9 ± 2.8 ISQ and 57.5 ± 0.5 ISQ, respectively). ISQ values determined by the device on one-piece and two-piece implants were similar (57.4 ± 0.9 and 57.5 ± 0.5, respectively). CONCLUSION: With the present validation of this external fixation device for the measurements of implant stability using RFA, it is now possible to measure primary stability of any one-piece implant system, obviating the need for custom-made Osstell adaptors.

Chronic blockade of interleukin-1 (IL-1) prevents and attenuates neuropathic pain behavior and spontaneous ectopic neuronal activity following nerve injury.

Neuropathic pain is a chronic pain state resulting from peripheral nerve injury, characterized by hyperalgesia and allodynia. We have reported that mice with genetic impairment of IL-1 signaling display attenuated neuropathic pain behavior and ectopic neuronal activity. In order to substantiate the role of IL-1 in neuropathic pain, WT mice were implanted subcutaneously with osmotic micropumps containing either IL-1ra or vehicle. Two days following the implantation, two models of neuropathic pain were used; partial nerve injury (spinal nerve transection, SNT), or complete nerve cut (spinal neuroma model). Mechanosensitivity was assessed seven consecutive days following SNT, and on day 7 recordings of spontaneous ectopic activity were performed. In the spinal nerve neuroma model, autotomy scores were recorded up to 35 days. Vehicle-treated mice developed significant allodynia and autotomy, and clear ectopic activity (4.1±1.1% of the axons); whereas IL-1ra-treated mice did not display allodynic response, displayed delayed onset of autotomy and markedly reduced severity of autotomy scores, and displayed reduced spontaneous activity (0.8±0.4% of the axons). To test whether IL-1 is involved in maintenance of mechanical allodynia, a separate group of WT mice was treated with a single injection of either saline or IL-1ra four days following SNT, after the allodynic response was already manifested. Whereas saline-treated mice displayed robust allodynia, acute IL-1ra treatment induced long-lasting attenuation of the allodynic response. The results support our hypothesis that IL-1 signaling plays an important role in neuropathic pain and in the ectopic neuronal activity that underling its development.