Survival of temporomandibular total joint replacement: A systematic review and meta-analysis.

BACKGROUND: Prosthetic total joint replacement has been incorporated as a treatment for complex temporomandibular disorder; however, the survival of those devices is unknown. OBJECTIVE: To assess the survival rate of the total temporomandibular joint (TMJ) prothesis and their main causes of failure. METHODS: An electronic search was conducted in eight databases until March 2023. Prospective studies reporting the survival rate of total TMJ prothesis with a minimum follow-up of 12 months were included. Studies with partial TMJ prostheses or those no longer available on the market were excluded. Two reviewers assessed the individual risk of bias using the JBI Systematic Reviews for Quasi-experimental studies tool. Meta-analysis of proportions was conducted to summarise the survival rate, using 95% confidence intervals (CI). The GRADE approach assessed the certainty of the body of evidence. RESULTS: Data from 320 patients were collected from six prospective studies. The number of prothesis losses varied from none to four. All studies presented sources of bias related to follow-up description of the patients. The follow-up time varied from 12 months to 21 years. In most of the studies, prosthesis failure occurred within the first 6 months after surgery due to infection. The overall survival of total TMJ protheses was 97% (95% CI: 95%; 99%), with low heterogeneity (I2 = 29%) and a very low certainty of evidence. CONCLUSION: TMJ total prosthesis apparently is a safe procedure with a high survival rate and the evidence is very uncertain and presents important sources of bias.

Evaluation of mandibular implant-supported fixed prosthesis retained by 3 dental implants, 1 straight and 2 angled: A retrospective clinical study.

STATEMENT OF PROBLEM: The minimum number of implants to support fixed complete dentures is still unclear. PURPOSE: The purpose of this retrospective clinical study was to evaluate the survival rate of fixed complete dentures supported by 3 immediately loaded implants opposing maxillary complete dentures. MATERIAL AND METHODS: A retrospective study of edentulous patients rehabilitated with complete dentures opposing mandibular metal-resin implant-supported fixed complete dentures supported by 3 immediately loaded implants was conducted in a 48-hour protocol. Fifty-one machined and 99 rough-surface implants were evaluated from 2.2 up to 8 years. Implant loss, peri-implant outcomes, and mechanical complications were assessed by considering the influence of age, sex, health status, smoking, excessive alcohol consumption, educational level, and socioeconomic status. The presence of comorbidities in relation to the implant surface or the cantilever lengths was also evaluated. RESULTS: Four machined and 6 rough-surface implants failed, a 6.7% failure rate. The cantilever length varied from 3.3 to 22.9 mm. Mechanical complications were abutment screw loosening (3.0%), prosthetic screw loosening (17%), screw fracture (1%), superstructure detachment and fractures (16%), metal framework fracture (2%), maxillary denture fractures (6%), and mandibular prosthesis loss (4%). Peri-implant mucositis was found in 27% of participants. The cumulative implant and mandibular prosthesis survival rates were 93.3% and 96%, respectively. None of the variables evaluated, including demographic data and health status, were found to influence clinical failures and/or mechanical complications. CONCLUSIONS: Mandibular fixed complete dentures supported by 3 implants can be considered a successful treatment with reduced costs compared with those of other fixed options for application in public health.

Does the natural maxillary dentition influence the survival rate of mandibular metal-resin implant-supported fixed complete dentures? A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Consensus is lacking regarding the influence of the maxillary dentition on the survival rate of a mandibular metal-resin implant-supported fixed complete denture (MRISFCD) with distal cantilevers. PURPOSE: The purpose of this systematic review was to identify whether an opposing natural dentition influences the survival rate of mandibular MRISFCDs. MATERIAL AND METHODS: A literature search was performed up to February 2018 from MEDLINE/PubMed, Scopus, Web of Science, Cochrane Library, BBO/LILACS databases and also in the non-peer-reviewed literature through Open Grey. Clinical studies regarding natural (ND), removable prostheses (RP), and complete fixed maxillary implant dentitions (ID) with at least a year of follow-up were included. The quality of the included studies was analyzed, and the risk of bias was reported. A meta-analysis comparing the survival rate of ND with RP and ND with ID was performed with a confidence interval (CI) of 95%, and heterogeneity was tested by an I2 index. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to determine the certainty of the evidence. RESULTS: From a total of 112 ND, 69 ID, and 204 RP in the maxillary dentition, the overall prevalence of failures was 5.4% (6/112; 95% CI [2.3 to 10.76]) for ND, 13.99% (20/69; 95% CI [0.77 to 39.41]) for ID, and 4.9% (10/204; 95% CI [0.69 to 12.18]) for RP. No statistical differences were detected in the success rates between ND and RP (risk difference = 0.00 [-0.06, 0.06]; P=.93; I2=27%) or between ND and ID (risk difference=0.00 [-0.06, 0.07]; P=.97; I2=0%), both with moderate evidence. CONCLUSION: With a moderate certainty of evidence, it is suggested that natural maxillary dentitions do not affect the survival rate of mandibular MRISFCDs differently from other prosthetic designs.

Effect of ionizing radiation after-therapy interval on bone: histomorphometric and biomechanical characteristics.

OBJECTIVES: This study aimed to evaluate the effects of radiotherapy on biomechanical, histomorphometric, and microstructural characteristics of bone, in diverse periods, compared with intact bone tissue. MATERIALS AND METHODS: Eighteen adult male New Zealand rabbits were treated with a single radiation dose of 30 Gy. The animals were randomly divided into six groups: NoIr, control group, no radiation, and five irradiated groups sacrificed after 24 h (Ir24h), 7 (Ir7d), 14 (Ir14d), 21 (Ir21d), and 28 (Ir28d) days. After these periods, the animals were sacrificed and their tibias (n = 6) evaluated using three-point bending test to calculate the ultimate force, work to failure, and bone stiffness. Dynamic indentation test was used to quantify Vickers hardness and elasticity modulus of bone tissue. Micro-CT was used to analyze the cortical volume (CtV), cortical thickness (CtTh), and porosity (Ct.Po). Histomorphometric assessment was based on the lacunarity of bone tissue. Data were analyzed using one-way ANOVA and Kruskal-Wallis tests followed by Tukey, Dunnet, and Dunn's post-tests (P < 0.05). RESULTS: The ultimate force, work to failure, stiffness, elastic modulus, and Vickers hardness values of irradiated bone were significantly lower that non-irradiated bone. Irradiated bone showed significantly lower CtTh and CtV values and higher CtPo than non-irradiated bone. No significant difference was found for lacunarity between non-irradiated bone and irradiated bone. CONCLUSIONS: Ionizing radiation decreases normal anisotropy on microarchitecture of cortical bone, and increases bone fragility compared with non-irradiated bone. Further, these changes were seen after longer periods (e.g., 14 and 21 days), and not immediately after radiation therapy. CLINICAL RELEVANCE: The radiotherapy reduces bone mechanical properties and the normal structure of organic and inorganic bone matrix. For studying the protocols to protect the radiotherapy effect using rabbit model, the use of the sacrificing period between 14 and 21 days is recommended.

Effect of titanium surface functionalization with bioactive glass on osseointegration: An experimental study in dogs.

PURPOSE: The purpose of this study was to evaluate the effect of surface functionalization with bioactive glass BSF18 on the osseointegration of sandblasted and dual acid-etched surface (AE) implants. METHODS AND MATERIALS: Forty Morse taper implants with an AE surface as controls (C) or with an AE surface functionalized with BSF18 (BF) were placed in the mandibles of 10 beagles. Implants were analyzed after 2 and 4 weeks of healing. Implant stability quotient (ISQ) values were registered immediately after installation and prior to sacrifice. Samples were analyzed for bone-to-implant contact (BIC) and bone density (BD). The characterization of BF implants included surface roughness analysis with atomic force microscopy and contact angle (CA) analysis to evaluate wettability. Data were analyzed using two-way ANOVA followed by Tukey's test (p < 0.05). RESULTS: Surface roughness was not affected by BF treatment. CA was lower in the BF group compared to the C group. No significant difference was observed in ISQ values between surfaces (p = 0,231), irrespective of time. Significantly higher ISQ values were observed for both implants after 4 weeks when compared with baseline (p = 0.04). Significantly higher BIC (p = 0.011) and BD (p = 0.025) values were observed for the BF compared to the C group at 2 weeks. Significantly higher BIC (p = 0.030) and BD (p = 0.015) values for the C group were observed at 4 weeks compared to 2 weeks. No significant difference was observed in the BF group between 2 and 4 weeks. CONCLUSIONS: Implant functionalization with BSF18 improved the wettability of the implant surface; enhancing BIC and BD at 2 weeks.

Influence of Platelet-Poor Plasma on Angiogenesis and Maintenance of Volume in Autogenous Bone Grafts.

PURPOSE: The aim of this study was to evaluate the effect of different storage media on angiogenesis and maintaining autogenous bone graft volume in rabbits. MATERIAL AND METHODS: Two grafts were removed bilaterally from the calvaria of 18 rabbits. One graft was removed and immediately fixed in the right mandibular angle (control group). The other graft was stored for 30 minutes in 1 of the following storage media (n = 6): saline solution (saline group), air exposure (dry group), or platelet-poor plasma (PPP group) and then retained by a screw in the right mandibular angle in the same animal. Four weeks later the animals were euthanized, and the grafted areas were harvested, fixed in 10% phosphate buffered formaldehyde solution, and embedded in paraffin. The 5-µm semi-serial sections were stained in hematoxylin and eosin and Mallory trichrome. RESULTS: Histologic analysis of all groups showed the bone graft was vascularized and well incorporated into the recipient site. The number of blood vessels decreased in the saline and dry groups compared with the control group (P < .03); in contrast, the number of blood vessels increased in the PPP group (P < .05). There were fewer osteoclasts in the saline group compared with the control group (P < .05). Furthermore, the saline group showed larger numbers of blood vessels than the dry group (P < .01). The PPP group showed larger bone graft volumes compared with the dry and saline groups (P < .01). In addition, the saline group showed larger bone graft volumes than the dry group (P < .01). CONCLUSIONS: PPP improved angiogenesis, maintained the volume of the autogenous bone graft, and was a better storage medium during the trans-surgical period than the dry and saline media.

Histomorphometric evaluation of a dual acid-etched vs. a chemically modified hydrophilic dual acid-etched implant surface. An experimental study in dogs.

OBJECTIVE: The aim of this preclinical in vivo study was to compare histologically and histomorphometrically osseointegration of dual acid-etched vs. hydrophilic implants. MATERIAL AND METHODS: Two pairs of implants (Neodent, Curitiba, Brazil), with same macrogeometry but different surface technology (i) dual acid-etched surface (SAE) treatment with hydrochloric and sulfuric acid followed by microwave treatment and insertion in isotonic saline solution to increase hydrophilicity (SAE-HD) (test, n = 12); (ii) dual SAE (control, n = 12) were installed bilaterally in the proximal tibia of six beagle dogs. Histologic and histomorphometric evaluation was performed after 2 and 4 weeks in vivo, on non-decalcified sections. Percentages of bone-to-implant contact (BIC) and bone density (BD) were estimated and tested for significant differences with the Wilcoxon signed-rank test for paired samples (P < 0.05). RESULTS: In general, new bone formation along and in contact with the implant surface could be observed irrespective of the experimental group and observation period. Most of the bone was woven but small quantities of lamellar bone, mainly in close proximity to the cortex could also be observed. BIC at 2 weeks was 19.57 ± 13.57 and 20.33 ± 7.99 (P = 0.75), and at 4 weeks was 42.80 ± 14.48 and 40.25 ± 9.45 (P = 0.65) for SAE-HD and SAE implants respectively. BD at 2 weeks was 24.85 ± 16.31 and 25.66 ± 8.59 (P = 0.35) and at 4 weeks 44.13 ± 6.46 and 40.13 ± 6.46 (P = 0.25) for SAE-HD and SAE implants respectively. CONCLUSION: Bone-to-implant contact and BD increased with time in both SAE-HD and SAE implants. No significant differences were observed between the two different implant surfaces for any of the evaluated parameters and at any observation time-point.

Drilling dimension effects in early stages of osseointegration and implant stability in a canine model.

BACKGROUND: This study histologically evaluated two implant designs: a classic thread design versus another specifically designed for healing chamber formation placed with two drilling protocols. STUDY DESIGN: Forty dental implants (4.1 mm diameter) with two different macrogeometries were inserted in the tibia of 10 Beagle dogs, and maximum insertion torque was recorded. Drilling techniques were: until 3.75 mm (regular-group); and until 4.0 mm diameter (overdrilling-group) for both implant designs. At 2 and 4 weeks, samples were retrieved and processed for histomorphometric analysis. For torque and BIC (bone-to-implant contact) and BAFO (bone area fraction occupied), a general-linear model was employed including instrumentation technique and time in vivo as independent. RESULTS: The insertion torque recorded for each implant design and drilling group significantly decreased as a function of increasing drilling diameter for both implant designs (p<0.001). No significant differences were detected between implant designs for each drilling technique (p>0.18). A significant increase in BIC was observed from 2 to 4 weeks for both implants placed with the overdrilling technique (p<0.03) only, but not for those placed in the 3.75 mm drilling sites (p>0.32). CONCLUSIONS: Despite the differences between implant designs and drilling technique an intramembranous-like healing mode with newly formed woven bone prevailed.

Effect of indomethacin on surface treatment and intracanal dressing of replanted teeth in dogs.

PURPOSE: This study evaluated the healing process of teeth replanted after root treatment and intracanal dressing with indomethacin alone or indomethacin with calcium hydroxide (Ca[OH]2). MATERIALS AND METHODS: Through a case-control study, 24 teeth of 6 adult dogs were extracted, dried, and divided into 4 groups according to the root surface treatment protocols performed before replantation and the intracanal medication used after replantation. In group 1 (negative control), root surfaces were treated by immersion in a 0.9% saline solution and then replanted. In the other groups, the roots were immersed for 10 minutes in Ca(OH)2 (group 2), indomethacin (group 3), or a solution of indomethacin and Ca(OH)2 (group 4). After 2 weeks, group 1 teeth were subjected to single-visit root canal treatment and obturation with gutta-percha and sealer consisting of zinc oxide and eugenol. The teeth in the other groups were subjected to intracanal dressing with the same material used for immersion. After an additional period of 28 weeks, the animals were euthanized and the jaws containing the replanted teeth were processed for histologic analysis. Histometric values were statistically analyzed, with significance set at a P value less than or equal to .05. RESULTS: Group 1 exhibited significantly more normal periodontium than group 4 (P = .02). Total resorption was greater in group 4 than in group 1 (P = .02). No statistically significant difference in the percentage of surface resorption or in total inactive resorption was observed between the groups. CONCLUSIONS: The findings of this study suggest that intracanal dressing and topical root treatment with Ca(OH)2 with or without indomethacin is not recommended for teeth dried for 50 minutes, but the use of indomethacin alone as root surface treatment for delayed tooth replantation deserves further study using longer drying periods. In addition, the present results suggest that a single-visit root canal, performed up to 2 weeks after replantation, might be indicated for teeth dried for up to 50 minutes.

Effect of low-level laser therapy on repair of the bone compromised by radiotherapy.

Radiotherapy (RDT) is commonly used for cancer treatment, but high doses of ionizing radiation can directly affect healthy tissues. Positive biological effects of low-level laser therapy (LLLT) on bone repair have been demonstrated; however, this effect on surgical defects of bone previously compromised by radiotherapy has not been evaluated. The aim of this study was to investigate the influence of LLLT (λ = 830 nm) in femur repair after ionizing radiation. Twenty Wistar rats were divided into four groups: control group (GC, n = 5) creation of bone defects (BDs) only; laser group (GL), with BD and LLLT (n = 5); radiotherapy group (GR), submitted to RDT and BD (n = 5); and radiotherapy and laser group (GRL), submitted to RDT, BD, and LLLT (n = 5). GL and GRL received punctual laser application (DE = 210 J/cm(2), P = 50 mW, t = 120 s, and beam diameter of 0.04 cm(2)) immediately after surgery, with 48-h interval during 7 days. Animals were euthanized at 7 days after surgery, and bone sections were evaluated morphometrically with conventional microscopy. Bone repair was only observed in nonirradiated bone, with significant improvement in GL in comparison to GC. GR and GRL did not present any bone neoformation. The result demonstrated a positive local biostimulative effect of LLLT in normal bone. However, LLLT was not able to revert the bone metabolic damage due to ionizing radiation.

Treatment of temporomandibular joint ankylosis by posterior border of mandibular ramus osteotomy.

Temporomandibular joint (TMJ) ankylosis (TMJA) is an anatomic and functional alteration of the TMJ surfaces, caused by the fusion of these surfaces by either bone or fibrous tissue. Several techniques are used for the treatment of TMJA. The following case report describes a 5-year-old boy who was diagnosed with TMJA. The treatment of choice is reconstruction of the condyle by sliding the posterior border of the mandibular ramus. Temporomandibular joint ankylosis treatment with vertical ramus osteotomy and mandibular posterior border repositioning offers minimizing the reduction in height or shortening of the mandibular posterior border. The postoperative period requires a multidisciplinary approach with an aggressive physiotherapy.

Potential of coconut water and soy milk for use as storage media to preserve the viability of periodontal ligament cells: an in vitro study.

AIM: There is no consensus regarding the ability of coconut water and soy milk to maintain long-term cell viability. This study investigated the ability of pH-adjusted coconut water and soy milk to maintain the viability of periodontal ligament cells over a short and a longer period and compared these abilities with those of other solutions. METHODS: Dog premolar teeth were extracted, dried for 30 min, and stored in the following media for 50 min or 24 h: long shelf-life whole milk (SWM), long shelf-life skim milk (SSM), Hank's Balanced Salt Solution (HBSS), soy milk (SM), and pH-adjusted coconut water (CW). The positive and two negative control groups corresponded to 0-min, 30-min (short-term), and 24-h (long-term) dry times, respectively. Cell viability was analyzed by trypan blue exclusion. Data were statistically analyzed using the Kruskal-Wallis test with post-analysis using the Dunn method. RESULTS: In the short-term experiment, the SSM resulted in significantly lower cell viability than SM and CW. At 24 h, SM and CW resulted in higher viability than HBSS and SSM and in comparable performance with the positive control group. Cell viability decreased over time, except in SM and CW. CONCLUSIONS: Soy milk and pH-adjusted coconut water showed promising results as storage solutions for avulsed teeth, preserving the viability for up to 24 h.

Saliva versus peri-implant inflammation: quantification of IL-1ß in partially and totally edentulous patients.

The aim of this study was to investigate the potential use of salivary IL1ß in early-stage diagnostics of peri-implant inflammation in partially and totally edentulous patients rehabilitated with dental implants. Patients were classified according to peri-implant probing depth and bleeding upon probing in groups of healthy individuals or in groups of individuals with peri-implant inflammation. Data on plaque index, clinical attachment loss, suppuration, and mobility were also assessed. Saliva was collected without stimulation, and the levels of IL-1ß were determined by ELISA. Healthy groups demonstrated significantly lower levels of IL-1ß compared with the inflammation groups. No difference in IL-1ß levels was observed between partially edentulous or totally edentulous patients. Salivary IL-1ß may be useful for the diagnosis and monitoring of early peri-implant inflammation, particularly in edentulous patients.

Oversized Surgical Preparation of the Implant Site: Systematic Review and Meta-analysis of Preclinical Studies.

PURPOSE: To answer the following focus question: In preclinical in vivo experimental models, do oral implants placed in overdimensioned (OD) sites present greater biomechanical properties and histomorphometric parameters of osseointegration compared to implants placed in standard or undersized implant sockets? MATERIALS AND METHODS: Online databases were searched for controlled animal studies reporting on OD sites up to February 2023. The relative implant- final drill discrepancy (IDD) was used to categorize the control and test groups according to surgical drilling protocol: (1) control: undersized (IDD > 0.5 mm) or standard (IDD = 0.2 to 0.5 mm); and (2) test OD: stress-free oversized (IDD = 0.0 to -0.1 mm); test GAP: friction-free oversized (IDD ≤ -0.1 mm). Random-effects meta-analyses were performed for the outcomes of insertion and removal torque values (ITV and RTV, respectively), bone-to-implant contact (%BIC), and bone density (%BD) for short- (0 to 2 weeks), intermediate- (3 to 4 weeks), and long-term (≥ 5 weeks) healing periods. RESULTS: Of the 527 records identified, 13 studies met the eligibility criteria. Histologically, the OD and GAP groups prevented ischemic necrosis and extensive bone resorption at the bone-implant interface in both the marginal cortical layer and the trabeculae. Faster and increased rates of bone formation, characterized by primary osteons and highly vascularized tissue, took place in OD sites between 1 and 5 weeks of healing. Meta-analyses indicated statistically significant benefits in favor of (1) control vs OD for short-term healing in extraoral sites, with pooled estimates (weighted mean difference) of ITV = 25.35 Ncm, %BIC = 2.10%, and %BD = 26.19%; (2) control vs OD for long-term healing in intraoral sites, with %BD = 11.69%; (3) control vs GAP for intermediate-term healing in extraoral sites, with %BD = 3.03%; and (4) control vs GAP for long-term healing in extraoral sites, with RTV = 5.57 Ncm. CONCLUSIONS: Oversized surgical preparation of the implant site does not seem to provide any additional benefit compared to standard or undersized sites regarding quantitative parameters of osseointegration. However, it does minimize marginal bone resorption and yields better-quality bone healing, despite the comparable results among different experimental animal models in the late postoperative period.

Assessment of the epidemiological profile of patients with dentofacial deformities who underwent orthognathic surgery.

The present study aimed to establish the profile of patients who underwent orthognathic surgery in a private clinic by evaluating their demographic characteristics, their facial types, and aspects related to the surgical procedures that were performed. The sample consisted of 419 medical records from male and female patients aged 15 to 62 years who underwent orthognathic surgery between 2001 and 2011. A single examiner collected data by evaluating a database of information extracted from medical records, particularly radiographic and photographic analyses. The following criteria were evaluated: gender, age, skin color, type of orthognathic surgery, type of associated temporomandibular joint (TMJ) surgery, complications, and recurrences. Seventeen patients were rejected because they had incomplete records. The average age of the patients was 28.5 years old; most were females (255 patients) and faioderm (295 patients). The most prevalent facial pattern was Pattern III (n = 166, 41.3%). Orthognathic surgery that affected the maxilla, jaw, and chin was the most prevalent type (n = 199, 49.5% of cases). A genioplasty was performed concurrently with combined surgeries and single-jaw surgery in 76.86% of patients (n = 309). TMJ surgery was performed concomitantly with orthognathic surgery in 4% of cases (n = 16). The most common postoperative complication was infection/inflammation (n = 12). We concluded that there was a higher frequency of orthognathic surgery among women and young people, the brunette skin phenotype was prevalent, and most patients had a combination of maxillary and mandibular problems.

Effect of different storage media on the regenerative potential of autogenous bone grafts: a histomorphometrical analysis in rabbits.

The success of autogenous bone graft is related to the graft cell viability. In bone-grafting procedures, harvested grafts are often maintained in extraoral media while the recipient site is prepared. The aim of this study was to evaluate in vivo the effect of storage media over autogenous bone grafts during the transsurgical time. Two grafts were removed bilaterally from the calvaria of 18 rabbits. One graft was immediately fixed in the mandibular angle (control group), and the other was maintained in air exposure (dry group), 0.9% NaCl solution (saline group), or platelet-poor plasma (PPP group) during 30 minutes and stabilized in the symmetrical location of control grafts. After 28 days, the animals were euthanized and the bone fragments were removed, demineralized, and embedded in paraffin. Histological evaluation was performed under light microscope. Empty lacunae and bone graft area quantification were carried out for the sections. The histomorphometrical analysis revealed reduction of the graft area and increase of empty lacunae in the dry group when compared with control. No significant differences were found in the number of empty lacunae or bone graft area between the saline group and its control and also between the PPP group and its control. The dry group showed more empty lacunae and less graft area than the saline and PPP groups. In accordance with the results, PPP and physiologic solution demonstrated osteocyte preservation and bone graft area maintenance, being satisfactory storage media for autogenous bone grafts during the transsurgical period.

Would nitric oxide be an effective marker for earlier stages of peri-implant disease? An analysis in human peri-implant sulcular fluid.

Nitric oxide has an important effect on host immune response. However, little has been studied in relation to its potential as a possible diagnostic tool in peri-implant disease. The present study analyzed nitrite levels in the peri-implant sulcular fluid (PISF) of implants with mucositis and the correlation of these nitrite levels with clinical parameters using a simplified fluid collection methodology. Twenty-five partially edentulous patients showing peri-implant mucositis were evaluated, and the peri-implant status was determined based on current clinical parameters: probing depth (PD) and bleeding on probing (BOP). The sulcular fluid (SF) around teeth (control) and implants were collected, and the nitrite levels were evaluated using the Griess method. The mean probing depth (mm) was significantly higher (P < .0001) in implants (2.852 ± 0.6484) than in control teeth (1.585 ± 0.3636). The mean total nitrite level (µM) was statistically higher (P = .0069) in implants with mucositis (14.34 ± 11.83) than in control teeth (9.316 ± 5.534). No correlation was observed between the total nitrite levels and the PD mean in the control group (P = .2558, r = -0.2361) or in the implant group (P = .1160, r = -0.3224), as well as the number of faces showing bleeding on probing (P = .8747, r = 0.0332). These results demonstrated that the nitrite levels were higher in inflamed areas. According to the methodology applied and results obtained, the higher nitrite levels in inflamed areas suggest that, in the future, nitrite could be used as a marker of peri-implant mucositis associated with clinical data to monitor the cure or evolution of the disease.

Evaluation of the bone healing process utilizing platelet-rich plasma activated by thrombin and calcium chloride: a histologic study in rabbit calvaria.

To evaluate the bone healing of defects filled with particulate bone graft in combination with platelet-rich plasma (PRP), added with a mixture of calcium chloride and thrombin or just calcium chloride. Two 5-mm bone defects were created in the calvaria of 24 rabbits. Each defect was filled with particulate bone graft and PRP. In one defect the PRP was activated by a mixture of calcium chloride and thrombin; in the other, PRP was activated by calcium chloride only. The animals were euthanized 1, 2, 4, and 8 weeks after the surgeries, and the calvaria was submitted to histologic processing for histomorphometric analysis. The qualitative analysis has shown that both defects presented the same histologic characteristics so that a better organized, more mature, and well-vascularized bone tissue was noticed in the eighth week. A good bone repair was achieved using either the mixture of calcium chloride and thrombin or the calcium chloride alone as a restarting agent of the coagulation process.

Effect of drilling dimension on implant placement torque and early osseointegration stages: an experimental study in dogs.

PURPOSE: Primary stability has been regarded as a key factor to ensure uneventful osseointegration of dental implants. Such stability is often achieved by placing implants in undersized drilled bone. The present study evaluated the effect of drilling dimensions in insertion torque and early implant osseointegration stages in a beagle dog model. MATERIALS AND METHODS: Six beagle dogs were acquired and subjected to bilateral surgeries in the radii 1 and 3 weeks before death. During surgery, 3 implants, 4 mm in diameter by 10 mm in length, were placed in bone sites drilled to 3.2 mm, 3.5 mm, and 3.8 mm in diameter. The insertion torque was recorded for all samples. After death, the implants in bone were nondecalcified processed and morphologically and morphometrically (bone-to-implant contact and bone area fraction occupancy) evaluated. Statistical analyses were performed using the Kruskal-Wallis test followed by Dunn's post hoc test for multiple comparisons at the 95% level of significance. RESULTS: The insertion torque levels obtained were inversely proportional to the drilling dimension, with a significant difference detected between the 3.2-mm and 3.8-mm groups (P = .003). Despite a significant increase in the bone-to-implant contact over time in vivo for all groups (P = .007), no effect for the drilling dimension was observed. Additionally, no effect of the drilling dimension and time was observed for the bone area fraction occupancy parameter (P = .31). The initial healing pathways differed between implants placed in bone drilled to different dimensions. CONCLUSIONS: Although different degrees of torque were observed with different drilling dimensions and these resulted in different healing patterns, no differences in the histometrically evaluated parameters were observed.