Effect of Microthread Design on Marginal Bone Level Around Dental Implants Placed in Fresh Extraction Sockets.

PURPOSE: This study was designed to compare radiographically the effect of microthread on the coronal portion of the fixture on marginal bone level (MBL) around immediately placed dental implants in human subjects. MATERIAL AND METHODS: Forty-one roughened surface screw type Dentium oral implants (Dentium) were inserted in fresh extraction sockets of the anterior segment of maxilla of 30 patients. The implants were selected randomly using either microthread design on coronal portion of the fixture (Implantium) (test group) or without microthread thread design (Superline) (control group). MBL was measured using digital subtraction radiography technique after 3, 6, and 12 months. RESULTS: At month 3, the microthread groups have been associated with more marginal bone loss than the control group (P = 0.04). At months 6 and 12, both groups had comparable bone levels (P = 0.21). CONCLUSION: The microthread design of the implant collar could not have a positive effect in maintaining the MBL around implants placed in fresh extraction socket in anterior maxilla.

Comparison of amnion allograft with connective tissue graft for root coverage procedures: a double-blind, randomized, controlled clinical trial.

OBJECTIVE: The aim of the present double-blind, randomized, controlled study was to evaluate and compare the efficacy of amnion allograft and connective tissue graft in covering denuded root surfaces. METHODS: Seventy-one teeth in 22 patients with gingival recession were treated randomly with coronally displaced flap plus connective tissue graft (control group, n = 29 recessions in 10 patients) or coronally displaced flap plus amnion allograft (test group, n = 42 recessions in 12 patients). The amount of root coverage and clinical parameters (probing depth, recession depth, clinical attachment level, recession width, gingival width, and papilla dimensions) were measured at baseline and at 3 and 6 months postoperatively. RESULTS: Average root coverage percentages after 6 months in the test and control groups were 67% (2.3 +/- 0.289 mm) and 54% (2.24 +/- 0.519 mm), respectively, with no statistically significant differences (p = 0.054). The changes in depth and width of recessions and in gingival width were significant 3 and 6 months after surgery compared to baseline (p = 0.000). Variations in the level of attachment and probing depths after 6 months were statistically significant in the test group compared to the control group (p = 0.002). Papilla dimensions were significantly correlated with root coverage (p = 0.00). CONCLUSIONS: Amnion allograft might be a suitable alternative to connective tissue graft in procedures to cover denuded root surfaces and can reduce recession depth.

Effect of static magnetic fields on the osseointegration of immediately placed implants: a randomized controlled clinical trial.

PURPOSE: The aim of this study was to evaluate the effects of static magnetic fields (SMFs) on the implants immediately placed in fresh extraction sockets. MATERIALS AND METHODS: Twenty patients who were in need of 20 fixed implant-supported single crowns in the anterior maxilla were included. After tooth extraction, screw-type implants were placed immediately into fresh extraction sockets and were randomly covered with either magnetic abutment (test group) or conventional healing abutment (control group). Radio frequency analysis (RFA) was conducted at implant placement and after 1, 2, and 3 months. Marginal bone level changes were recorded 1, 2, and 3 months postoperatively. RESULTS: The RFA measurements showed a significant higher stability for implants in test group than that of control group after 1 month (P = 0.04). At month 2, less crestal bone loss was found in the test group (P = 0.03). However, at month 3, there was no significant difference between the groups for both parameters (P > 0.05). CONCLUSION: SMFs caused more noticeable increase in implant stability and less bone loss during the initial weeks of healing.

Marginal bone loss around bone-level and tissue-level implants: A systematic review and meta-analysis.

PURPOSE: To review the scientific evidence regarding the marginal bone loss around the tissue-level and bone-level implants. METHODS: MEDLINE-PubMed and EMBASE databases were searched for the relevant English articles (up to February 2019) assessing the marginal bone loss (MBL) as the primary outcome. To be selected, studies were supposed to directly mention "tissue-level" and "bone-level" implants or implants with and without a smooth neck. Relevant data were extracted and meta-analysis was performed to evaluate the effect of implant neck design. RESULTS: A total of 19 studies (10 clinical, and 9 RCT studies) were included for qualitative analysis. There was a vast heterogeneity between studies in terms of implant designs and study protocol. Out of 19 articles included, 11 studies reached to a statistically significant difference in MBL between the groups; however, the differences were not found to be clinically relevant. Bone-level implants with platform-switched abutments in most of the cases showed better marginal bone stability compared to tissue-level implants or bone-level implants with matching abutments. Seven RCTs with 12 months follow-up data were selected for meta-analysis (I2=93%; heterogeneous), and the results showed less MBL around bone-level implants compared to tissue-level group (WMD=-0.21mm; 95% CI -0.42, 0.00; P=0.06). CONCLUSION: The available data regarding comparison of MBL around bone-level and tissue-level implants are heterogeneous. Bone-level implants with platform switching may better preserve crestal bone.

Effects of Qigong exercises on 3 different parameters of human saliva.

OBJECTIVE: To analyze the effects of a Qigong program on various parameters of unstimulated saliva, including volume, pH and secretory immunoglobulin A (S-IgA) level. METHODS: Twice a day from the beginning of Fall 2005, twenty-three healthy volunteers aged 22-24 did special Qigong exercises and massage of acupuncture points which stimulated the energy cycle and increased body water energy. The unstimulated saliva volume and pH were recorded every week in Spring (April, May, June) 2005 before the volunteers started to learn and exercise Qigong, and after Qigong intervention in Spring (April, May, June) 2006. During the period of study, saliva was collected in the same location and on similar dates at the Dental Faculty of Tehran University of Medical Sciences. The S-IgA levels of the last samples of the last week of Spring 2005 and 2006 were measured. RESULTS: The unstimulated saliva volume after Qigong exercises (2.94 + or - 0.20 mL/5min) was significantly higher as compared to the pre-Qigong phase (1.65 + or -0.102 mL/5min, P<0.05). The S-IgA level was 105.45 + or - 9.41 mg/mL before doing Qigong exercises, and 156.23 + or - 88.56 mg/mL after doing Qigong exercises, and a statistically significant difference was seen between the two measurements (P=0.005). The change in pH was not statistically significant. CONCLUSIONS: The application of Qigong is beneficial for increasing salivary volume and other parameters. Moreover, the results suggest that Qigong may be a useful medication for patients with salivary hyposecretion. Further research is recommended in examining the long-term effects of Qigong on improving salivary volume and other parameters in individuals with salivary hyposecretion.

Periosteal Releasing Incision With Diode Laser in Guided Bone Regeneration Procedure: A Case Series.

Introduction: Periosteal releasing incision (PRI) is nearly always essential to advance the flap sufficiently for a tension-free flap closure in bone augmentation procedures. However, hematoma, swelling, and pain are recognized as the main consequences of PRI with scalpel. The aim of this case series was to investigate the effectiveness of laser-assisted PRI in guided bone regeneration (GBR) procedure. In addition, postoperative hematoma, swelling, and pain and implant success were assessed. Methods: Seventeen patients needed GBR were included in this study. Diode laser (940 nm, 2 W, pulse interval: 1 ms, pulse length: 1 ms, contact mode, 400-µm fiber tip) was used in a contact mode to cut the periosteum to create a tension-free flap. Facial hematoma, swelling, pain, and the number of consumed nonsteroidal anti-inflammatory drugs (NSAIDs) were measured for the six postoperative days. Six months after implant loading, implant success was evaluated. Results: Minimal bleeding was encountered during the procedure. A tension-free primary closure of the flap was achieved in all cases. The clinical healing of the surgical area was uneventful. None of the patients experienced hematoma, ecchymosis, or intense swelling after surgery. The mean value of maximum pain (visual analogue scale - VAS) was 20.59 ± 12.10 mm (mild pain). Patients did not need to use NSAID after four postoperative days. All implants were successful and functional and none of them failed after 6 months of implant loading. Conclusion: This study revealed the effectiveness of laser-assisted PRI in GBR procedure. This technique was accompanied with minimal sequelae at the first postoperative week. All implants were successful and no complication was noted during the course of this study.

Accuracy of Cone Beam Computed Tomography for Detection of Bone Loss.

OBJECTIVES: Bone assessment is essential for diagnosis, treatment planning and prediction of prognosis of periodontal diseases. However, two-dimensional radiographic techniques have multiple limitations, mainly addressed by the introduction of three-dimensional imaging techniques such as cone beam computed tomography (CBCT). This study aimed to assess the accuracy of CBCT for detection of marginal bone loss in patients receiving dental implants. MATERIALS AND METHODS: A study of diagnostic test accuracy was designed and 38 teeth from candidates for dental implant treatment were selected. On CBCT scans, the amount of bone resorption in the buccal, lingual/palatal, mesial and distal surfaces was determined by measuring the distance from the cementoenamel junction to the alveolar crest (normal group: 0-1.5mm, mild bone loss: 1.6-3mm, moderate bone loss: 3.1-4.5mm and severe bone loss: >4.5mm). During the surgical phase, bone loss was measured at the same sites using a periodontal probe. The values were then compared by McNemar's test. RESULTS: In the buccal, lingual/palatal, mesial and distal surfaces, no significant difference was observed between the values obtained using CBCT and the surgical method. The correlation between CBCT and surgical method was mainly based on the estimation of the degree of bone resorption. CBCT was capable of showing various levels of resorption in all surfaces with high sensitivity, specificity, positive predictive value and negative predictive value compared to the surgical method. CONCLUSION: CBCT enables accurate measurement of bone loss comparable to surgical exploration and can be used for diagnosis of bone defects in periodontal diseases in clinical settings.

A comparative study of crestal bone loss and implant stability between osteotome and conventional implant insertion techniques: a randomized controlled clinical trial study.

PURPOSE: The aim of this prospective randomized controlled clinical study was to assess the crestal bone loss and the implant stability in implants that were placed by the osteotome technique compared with the conventional drilling technique. MATERIALS AND METHODS: Forty-six screw type Straumann SLA® oral implants (Straumann AG, Waldenburg, Switzerland) were inserted in the anterior segment of maxilla of 30 patients. The implant site was prepared randomly using either osteotome technique (test group) or the conventional drilling technique (control group). Radio frequency analysis (RFA) values at implant placement and after 3 months were recorded. The crestal bone loss was measured using digital subtraction radiography technique after 3, 6, and 12 months. RESULTS: RFA demonstrated a statistically significant higher primary stability for implants in the osteotome group than that of the conventional group (p=.026) at the time of implant insertion. However, there was no statistically significant difference between both groups 3 months after the surgery (p=.06). At month 3, the osteotome group caused significantly more crestal bone loss than the conventional group (p=.04). At months 6 and 12, both groups had comparable bone levels (p=.29). CONCLUSION: Osteotome technique yielded higher primary stability than conventional drilling technique. However, this technique was not superior to conventional technique after 3 months.

Localized bone augmentation with cortical bone blocks tented over different particulate bone substitutes: a retrospective study.

PURPOSE: To assess the efficacy of a block tenting technique for reconstruction of vertical or horizontal alveolar ridge defects. MATERIALS AND METHODS: Patients who underwent a block tenting graft technique between 2005 and 2010 were analyzed retrospectively. Intraoral bone blocks (ramus, chin, or tuberosity) or allogeneic blocks were fixed at 4 mm from the deficient area, and the gap was filled with bone substitutes, with or without plasma rich in growth factors (PRGF). Implants were placed simultaneously or 4 to 5 months postgrafting. Patient demographic information, amount of width/height augmentation after 4 to 5 months of healing, complications, and contributing factors were gathered and analyzed. RESULTS: One hundred two patients were enrolled. Among the horizontal augmentations, the greatest width increase was achieved in the anterior maxilla (4.31±0.93 mm). The average height increase in the vertically augmented regions was greatest in the posterior maxilla (5.75±2.22 mm). Mean horizontal augmentation was the greatest with ramus (3.65±0.65 mm) and allogeneic materials (3.97±0.79 mm). The greatest vertical gain was achieved with tuberosity blocks (4.25±3.06 mm) and a combination of allogeneic/autogenous bone particles (3.90±1.05 mm). Application of PRGF showed no appreciable effect. The most common primary complications of surgery were hematoma and inflammation. The most common complication in the anterior maxilla was hematoma. Inflammation was the most common complication associated with ramus grafts, while hematoma occurred most often in cases with chin and tuberosity grafts. Total graft failure occurred in 13 patients, mainly associated with the allogeneic blocks. Most patients were followed for 11 to 38 months. Five of 237 inserted implants failed to osseointegrate. CONCLUSION: The block tenting technique might be effective for localized ridge augmentation and may reduce the amount of autograft required from donor sites.

The effect of platelet-rich plasma on healing of palatal donor site following connective tissue harvesting: a pilot study in dogs.

BACKGROUND: Peri-implant plastic surgery includes soft tissue enhancement by connective tissue grafting. The palatal donor site provides peri-implant keratinized mucosa and soft tissue height. Platelet-rich plasma (PRP) contains growth factors that may enhance early healing. PURPOSE: The present animal study investigated the effect of PRP on wound healing of palatal donor site after connective tissue harvesting. MATERIALS AND METHODS: In 12 mongrel dogs, bilateral palatal connective tissues of 10 × 15 mm were harvested. At test site, PRP was applied into the wound, and the contralateral site served as control. The healing was evaluated clinically and histologically at 1 week, 2 weeks, and 4 weeks after surgeries. Exact binomial probability and Wilcoxon signed-rank test were used to compare the clinical and histologic measurements. RESULTS: No statistically significant differences between PRP and control sites were measured with regard to clinical healing (p = 1.000) and histologic variables, including inflammatory cells (p = .750), collagen fibers (p = .375), and granulation tissue (p = .500) at any time interval. CONCLUSION: The addition of PRP to palatal mucosal wound sites did not accelerate wound healing.

Implant placement in patients with oral bisphosphonate therapy: a case series.

BACKGROUND: Although the effect of bisphosphonates on dental implant osseointegration is not clear, dental implant failures attributable to oral bisphosphonate therapy have been reported in patients with osteoporosis. PURPOSE: The aim of this study was to evaluate implant survival in patients with a history of bisphosphonate therapy in a retrospective survey. MATERIALS AND METHODS: A total of 46 ITI implants placed in 21 osteoporotic patients (females; average age 53 years, range 42-79 years) were evaluated with regard to probing depth, mobility, thread exposure, and bleeding on probing. All patients were under oral bisphosphonate therapy. RESULTS: None of implants showed mobility and all patients could be considered free from peri-implantitis. Time of bisphosphonate therapy before and after implant insertion showed no statistically significant influence on PD, BOP, and TE. Likewise, implant location, prosthetic type, and opposing dentition had no statistically significant influence on the clinical and radiological parameters of implants. CONCLUSION: Within the limitations of this study, it could be concluded that neither being on oral bisphosphonate treatment before implant placement nor starting bisphosphonate therapy after implant installation might jeopardize the successful osseointegration and clinical and radiographic condition of the implants.

Sinus augmentation using human mesenchymal stem cells loaded into a beta-tricalcium phosphate/hydroxyapatite scaffold.

OBJECTIVE: Implant placement in the posterior maxilla may often be contraindicated because of insufficient bone volume and presence of the maxillary sinus. In these situations, sinus floor augmentation frequently has been proposed as the best treatment. This clinical study was based on the hypothesis that the clinical effectiveness of adult mesenchymal stem cells (MSCs) loaded to the biphasic scaffold. METHODS: In this report, the clinical and radiographic results are presented on 6 consecutively treated patients using MSCs in combination with biphasic hydroxyl apatite/ beta-tricalcium phosphate (HA/TCP) for sinus elevation. All the patients in the study had less than 3 mm initial bone height in the posterior maxillary area (IBH). MSCs were cultured and expanded from bone marrow aspirate for each patient. Three months after sinus elevation, radiographic evaluation was performed for the patients and the secondary bone height was measured (SBH(1)). In the second stage surgery, 30 implants were placed. Trephine bur was used as a pilot drill and a core biopsy was obtained from each implant site. Prosthetic rehabilitation of the patients was performed after 4 months. Secondary bone height was measured 9 months after implant placement (SBH(2)). RESULTS: Of 30 implants, 28 (93%) were considered clinically successful. Two implants were removed due to mobility at the time of surgical exposure. Histologic evaluation of the biopsy specimens revealed numerous areas of osteoid and bone formation HA/TCP, with no evidence of inflammatory cell infiltrate. Mean bone regenerate was 41.34%. Clinically, no complications were observed, and all implants were considered clinically osseointegrated after 4 months. Mean bone height was measured 3 and 12 months after sinus grafting (mean of SBH(1)= 12.08 mm and mean of SBH(2)= 10.08 mm). CONCLUSIONS: These clinical and histological findings suggest that sinus grafting with HA/TCP in combination with MSCs provide a viable therapeutic alternative for implant placement. The findings suggest that the addition of MSCs to bone derivative/substitute materials may enhance bone formation in the maxillary sinus area. Of course more studies with the control groups are needed for the evaluation of this method as a clinical solution for the patients.

The effect of a constant electrical field on osseointegration after immediate implantation in dog mandibles: a preliminary study.

PURPOSE: The long time span between insertion of implants and functional rehabilitation often inconveniences patients. Accelerating bone growth around dental implants can shorten this time span. This in vivo study evaluated the effect of a constant electrical field on bone growth around dental implants. MATERIALS AND METHODS: Four mongrel dogs were used in this study. Sixteen dental implants were placed immediately after extraction of the first premolar and molar teeth. A constant electrical field (CEF) generator was placed in the mucoperiostal pouch created from the subperiostral dissection under the inferior border of the dog's mandible and connected to the experiment side fixtures. CEF provided 3 V of electrical potential during osseointegration. Histologic sections were stained with hematoxylin-eosin and observed under light microscopy. The sections were analyzed histomorphometrically to calculate the amount of newly formed bone. Statistical analysis was performed with SPSS 11.0 computer software (alpha= 0.05). RESULTS: At the end of the first stage of the osseointegration (90 days) CEF group sections showed enhanced growth of the trabeculae compared with the control group. Statistical analysis revealed significant differences between experimental and control groups. Bone contact ratio was statistically significant in the experimental group (p= 0.001). An increase in the local bone formation and bone contact ratio was observed with direct electrical stimulation of the implant and the bone area around the implant. CONCLUSION: Minimal direct electrical current, which can produce an electrical field around the implant, can increase the amount of bone formation and decrease the time of osseointegration.