Evaluation of the bone regeneration potential of bioactive glass in implant site development surgeries: a systematic review of the literature.

OBJECTIVES: The aim of this systematic review was to assess the efficacy of bioactive glass (BG) in bone regeneration for implant site development procedures. MATERIAL AND METHODS: The following specific question was formulated with reference to Population, Intervention, Control, Outcomes (PICO): "In persons that undergo bone regeneration surgeries for implant site development, what histological outcomes does the use of BG yield, alone or in combination with AB, compared to positive or negative controls?". RESULTS: The 1st phase of screening yielded 400 titles and abstracts. A total of 12 studies reporting on the use of bioactive glass were scrutinized for inclusion in the final analysis and 5 studies were selected for qualitative synthesis of the results. Data were divided into two categories: ridge preservation (n = 2) and sinus augmentation (n = 3). CONCLUSIONS: Within the limitations of this review, it can be concluded that (1) the combination of BG with AB chips in a 1:1 ratio is an efficacious treatment modality for direct sinus augmentation, with histological results comparable to 100 % AB. (2) When used for ridge preservation, BG yields a high percentage of true bone regeneration. (3) Currently, no reliable controlled studies report histological outcomes from the use of BG in ridge augmentation procedures. CLINICAL RELEVANCE: Clinicians may consider BG bone substitutes as efficacious alternatives for ridge preservation and sinus augmentation surgical procedures. Further controlled clinical studies are warranted to determine if bone-to-implant contact is improved in BG-grafted sites versus controls.

Clinical results of implant placement in resorbed ridges using simultaneous guided bone regeneration: a multicenter case series.

OBJECTIVES: The purpose of this case series was to evaluate the new bone formation following guided bone regeneration (GBR) with a calcium phosphosilicate (CPS), alloplastic bone putty at peri-implant dehiscence defects and to assess survival rate of implants placed in the augmented sites after 12 months of function. MATERIALS AND METHODS: Implants were placed in patients exhibiting Seibert class I ridge defects resulting in peri-implant dehiscence defects. The defects were treated following GBR principles with the use of a CPS alloplastic bone graft putty in combination either with a collagen membrane or a titanium mesh. The height of each bony dehiscence was clinically measured at the time of implant placement and again during second-stage surgery. The percentage of complete defect coverage, frequency of adverse events, and risk factors for residual defect were determined. RESULTS: Thirty-six implants were placed in 26 patients. Twenty-seven of the 36 sites employed a collagen membrane in conjunction with the CPS while the remaining nine sites utilized a titanium membrane. Mean gain in bone height was 3.23 ± 2.04 mm, with 75 % of the peri-implant defects achieving complete regeneration. A negative correlation was identified between patient age and complete coverage of the peri-implant defect (p = 0.026). The implant survival rate at 12 months was 97.22 %. CONCLUSION: Use of CPS bone putty during delayed implant placement at peri-implant dehiscence sites either in combination with a collagen membrane or a titanium mesh results in predictable defect coverage. CLINICAL RELEVANCE: The handling characteristics of CPS putty may simplify GBR protocol. Implants placed in conjunction with GBR have a very good survival rate after 1 year of follow-up.

Risk Indicators of Papillary Recession in the Anterior Maxilla.

PURPOSE: The interdental papilla is the portion of the gingiva that occupies the space between two adjacent teeth. When papillary recession occurs, an array of problems arises ranging from phonetics to food impaction and esthetic concerns. The aim of this study was to identify risk indicators for visible papillary recession in the anterior maxilla among a Caucasian population utilizing an advanced analytical approach. MATERIALS AND METHODS: A dataset of 211 adult dentate Caucasian patients that had undergone intraoral assessment of midline papillary recession and extra-oral assessment of visible papillary recession during maximum ("Duchenne") smile was utilized. An enhanced analytical approach was employed to identify risk indicators for papillary recession. RESULTS: Approximately one-third of the participants (38%) demonstrated papillary recession during maximum smile ("visible papillary recession"). An association between sex (male preference) and visible papillary recession was found in this sample population, while age was found to be a risk indicator for papillary recession in individuals over 65 years of age. CONCLUSIONS: Visible midline papillary recession in the maxilla is a highly prevalent clinical entity in Caucasian individuals, thus the development of efficacious treatment modalities for papillary regeneration is necessary. Findings of the present study on risk indicators for visible papillary absence, namely sex and age, may facilitate clinicians in treating patient with compromised interdental aesthetics as well as identifying patients that are in high risk for loss of interdental tissues. CLINICAL SIGNIFICANCE: Findings of the present study on risk indicators for visible papillary absence, namely sex and age, indicate the need for careful assessment and meticulous treatment planning with respect to preservation of the interdental tissues. The consideration of these risk indicators can help dentists to identify patients at risk for papillary recession.

Patient-related and financial outcomes analysis of conventional full-arch rehabilitation versus the All-on-4 concept: a cohort study.

BACKGROUND: Patient-related variables such as cost of treatment, length of the treatment period, and comfort provided by the interim prosthesis when treatment planning for full-arch rehabilitation are often neglected in dental publications. METHODS: Two patient cohorts were followed up longitudinally in this study: the "All-on-4 treatment concept group" and the "historical group." The number of implants, total treatment time, number of surgical procedures, number of sinus grafts, necessity for immediate provisional implants, adjusted cost associated for treatment in each group, and the quality of interim prosthesis were compared. RESULTS: The total adjusted cost for patients receiving All-on-4 treatment concept averaged at $42,422 ± 3860 (&OV0556;31,392 ± 2856), whereas the mean total adjusted cost for the historical group was $57,944 ± 20,198 (&OV0556;42,879 ± 2113) (P = 0.01). The difference in cost had a mean value of $7307 (&OV0556;5407) per jaw. Factors associated with complexity of treatment and patient comfort, such as the quality of interim prosthesis, number of surgeries, and duration of treatment time, all significantly favored the All-on-4 treatment concept group in comparison with conventional treatment modalities. CONCLUSIONS: When implant rehabilitation of the total jaw is sought, the All-on-4 treatment concept should be considered the least costly and least time consuming treatment option.

Persistence of extracrevicular bacterial reservoirs after treatment of aggressive periodontitis.

BACKGROUND: The purpose of this study was to test the hypothesis that periodontal pathogens associated with aggressive periodontitis persist in extracrevicular locations following scaling and root planing, systemic antibiotics, and antimicrobial rinses. METHODS: Eighteen patients with aggressive periodontitis received a clinical examination during which samples of subgingival plaque and buccal epithelial cells were obtained. Treatment consisted of full-mouth root planing, systemic antibiotics, and chlorhexidine rinses. Clinical measurements and sampling were repeated at 3 and 6 months. Quantitative polymerase chain reaction determined the number of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), and Treponema denticola in the plaque. Fluorescence in situ hybridization and confocal microscopy determined the extent of intracellular invasion in epithelial cells. RESULTS: Clinical measurements improved significantly following treatment. All bacterial species except P. gingivalis were significantly reduced in plaque between baseline and 3 months. However, all species showed a trend to repopulate between 3 and 6 months. This increase was statistically significant for log T. denticola counts. All species were detected intracellularly. The percentage of cells infected intracellularly was not affected by therapy. CONCLUSIONS: The 6-month increasing trend in the levels of plaque bacteria suggests that subgingival recolonization was occurring. Because the presence of these species within epithelial cells was not altered after treatment, it is plausible that recolonization may occur from the oral mucosa. Systemic antibiotics and topical chlorhexidine did not reduce the percentage of invaded epithelial cells. These data support the hypothesis that extracrevicular reservoirs of bacteria exist, which might contribute to recurrent or refractory disease in some patients.

Peptide coatings enhance keratinocyte attachment towards improving the peri-implant mucosal seal.

There is a critical need for preventing peri-implantitis as its prevalence has increased and dental implants lack features to prevent it. Research strategies to prevent peri-implantitis have focused on modifying dental implants to incorporate different antimicrobial agents. An alternative strategy consists of barring the expansion of the biofilm subgingivally by forming a long-lasting permucosal seal between the soft tissue and the implant surface. Here, we innovatively biofunctionalized titanium with bioinspired peptide coatings to strengthen biological interactions between epithelial cells and the titanium surface. We selected laminin 332- and ameloblastin-derived peptides (Lam, Ambn). Laminin 332 participates in the formation of hemidesmosomes by keratinocytes and promotes epithelial attachment around teeth; and ameloblastin, an enamel derived protein, is involved in tissue regeneration events following disruption of the periodontium. Lam, Ambn or combinations of both peptides were covalently immobilized on titanium discs. Successful immobilization of the peptides was confirmed by contact angle goniometry, X-ray photoelectron spectroscopy and fluorescent labelling of the peptides. Additionally, we confirmed the mechanical and thermochemical stability of the peptides on Ti substrates. Proliferation and hemidesmosome formation of human keratinocytes (TERT-2/OKF-6) were assessed by immunofluorescence labelling. The peptide-coated surfaces increased cell proliferation for up to 48 h in culture compared to control surfaces. Most importantly, formation of hemidesmosomes by keratinocytes was significantly increased on surfaces coated with Ambn + Lam peptides compared to control (p < 0.01) and monopeptide coatings (p < 0.005). Together, these results support the Ambn + Lam multipeptide coating as a promising candidate for inducing a permucosal seal around dental implants.

Enhancing Root Eminence and Papilla Contour Using Single, Contoured, Subepithelial Connective Tissue Autografts for Recession Coverage.

Current techniques using autogenous soft tissue in periodontal plastic surgery have limitations in the number of teeth that can be treated and may result in suboptimal esthetic results. The innovative use of single, contoured grafts reported in this article overcomes the drawbacks associated with these techniques by more efficient use of available donor tissue. Autogenous tissue is used to graft each individual tooth, leaving the interdental areas uncovered. Multiple teeth-in some cases an entire arch-can be treated in one session, providing consistent and predictable reestablishment of the normal scalloped gingival architecture and convex root eminence.

No association between selected candidate gene polymorphisms and severe chronic periodontitis.

BACKGROUND: Chronic periodontitis (CP) risk is influenced by environmental and genetic factors. Using a case-control design, we tested for associations between CP and selected DNA sequence variations (single nucleotide polymorphisms [SNPs]) in or near genes coding for proteins that play a role in the pathogenesis of this disease. METHODS: DNA was analyzed from 219 whites who were examined clinically. Cases (N=137) were >or=35 years of age with eight or more teeth having >or=5 mm of proximal clinical attachment loss. Controls (N=82) were >or=45 years of age with minimal or no proximal attachment loss or pocketing. Nine diallelic polymorphisms (gene and SNP descriptor) were studied in subjects: cytotoxic T-lymphocyte antigen-4 (CTLA-4, 49 A>G), human beta-defensin-1 (DEFB1, 692 G>A), intercellular adhesion molecule-1 (ICAM-1, 1548 A>G), Fas ligand (fasL, -844 C>T), inducible costimulator (ICOS, 3990 G>T), interleukin-6 (IL-6, -174 G>C), cysteine-cysteine chemokine receptor-5 (CCR5, 59653 C>T), osteoprotegerin (OPG, 245 T>G), and osteopontin (OPN, 707 C>T). Genotypes were determined using an automated fluorogenic 5'-nuclease, polymerase chain reaction-based assay. Gender and smoking history (pack-years) were included as covariates in logistic regression analyses. RESULTS: Heavy smoking (>10 pack-years) and male gender were significantly associated with disease (P<0.001). For all SNPs tested, the allele frequencies and distributions of genotypes did not differ between cases and controls (P>0.05). No unadjusted or adjusted odds ratios (comparing genotypes in cases versus controls) were significantly different than 1.0 (P>0.05) under any additive, dominant, or recessive inheritance model. CONCLUSIONS: None of the SNPs tested were strongly associated with generalized severe chronic periodontitis in North American whites. A potentially more fruitful approach in future studies will be to test for associations between periodontitis and haplotype blocks constructed from either multiple SNPs in candidate gene regions or from panels of markers that span the entire genome.

Comparison of Initial Implant Stability of Implants Placed Using Bicortical Fixation, Indirect Sinus Elevation, and Unicortical Fixation.

PURPOSE: The aim of this study was to determine if self-threading dental implants placed using stopper drills to bicortically engage both the alveolar crest and sinus floor (bicortical fixation) achieved primary and/or secondary stability comparable to that of short implants only engaging alveolar crest cortical bone (unicortical fixation) or implants engaging both the crest and sinus floor but via greenstick fracture and grafting (indirect sinus elevation). MATERIALS AND METHODS: Thirty-eight patients exhibiting 7 to 11 mm of bone coronal to the sinus floor as confirmed by preoperative CBCT were recruited. Forty-five implants were randomly assigned to one of the placement techniques. No patient received more than two implants, which were placed in opposite sides of the maxilla while using different surgical techniques. An Osstell ISQ was employed immediately after implant placement to measure stability six times in a buccolingual dimension. Secondary stability was measured at stage-two surgery after a 3- to 6-month healing period. RESULTS: The greatest primary implant stability was achieved via indirect sinus elevation. However, no statistically significant difference was found among the three surgical techniques (P = .13; bicortical fixation: 71.4 [standard error = 2.1]), unicortical fixation: 69.6 [2.1], indirect sinus elevation: 75.9 [2.3]). The three techniques had similar secondary stability (P > .999; 79.9 [1.2], 80.0 [1.2], and 80.0 [1.3], respectively). Baseline residual ridge height measured on CBCT was similar (P = .1; 8.8, 9.9, and 9.4 mm, respectively), but implant diameter and length placed in the maxilla differed (P = .03/P < .001; 4.7/11.4 mm, 4.3/8.1 mm, and 4.7/11.8 mm, respectively). Primary implant stability was significantly correlated to CBCT bone density (r = 0.37). CONCLUSION: Primary and secondary implant stabilities of bicortical fixation did not differ significantly from those of unicortical fixation and indirect sinus elevation. However, use of the bicortical fixation technique is warranted since it is simpler and more economical than indirect sinus elevation; plus, it allows for longer implants than the unicortical fixation while yielding similar secondary implant stability.

Extraction Socket Management Utilizing Platelet Rich Fibrin: A Proof-of-Principle Study of the "Accelerated-Early Implant Placement" Concept.

Dental implants are widely accepted as the golden standard for the rehabilitation of an edentulous site following the extraction of a tooth. The ideal time for implant placement is dependent on the time required for partial or complete tissue healing and the adequacy of socket dimensions. The use of autologous growth factors is a promising new concept that aids clinicians in minimizing treatment time and increasing patient satisfaction. The purpose of this paper is to introduce a protocol for "accelerated-early" implant placement. In this protocol, platelet rich fibrin is employed to accelerate soft and hard tissue healing and to provide a better-healed recipient site for accelerated, early implant placement. Histological analysis revealed that at 6 weeks postextraction, the application of our approach resulted in delicate newly formed bone showing intense osteoblastic activity surrounded by connective tissue as well as areas of mineralized tissue. The present study is a proof-of-principle study of the acceleration of the physiologic postextraction healing sequelae with the use of autologous growth factors. The accelerated-early implant placement concept is a bioengineered protocol that may aid clinicians to achieve increased primary stability, by placing implants in ridges in an advanced stage of bone healing, while offering patients the benefits associated with early implant placement. Controlled studies are warranted to verify the reproducibility of this treatment concept and identify specific indications where the use of the presented technique can lead to significant clinical results.

Platelet-derived growth factor stimulates bone fill and rate of attachment level gain: results of a large multicenter randomized controlled trial.

BACKGROUND: Growth factors are generally accepted to be essential mediators of tissue repair via well-established mechanisms of action that include stimulatory effects on angiogenesis and cellular proliferation, ingrowth, differentiation, and matrix biosynthesis. The aim of this study was to evaluate in a large-scale, prospective, blinded, and randomized controlled clinical trial the safety and effectiveness of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (beta-TCP) matrix for the treatment of advanced periodontal osseous defects at 6 months of healing. METHODS: Eleven clinical centers enrolled 180 subjects, each requiring surgical treatment of a 4 mm or greater intrabony periodontal defect and meeting all inclusion and exclusion criteria. Subjects were randomized into one of three treatment groups: 1) beta-TCP + 0.3 mg/ml rhPDGF-BB in buffer; 2) beta-TCP + 1.0 mg/ml rhPDGF-BB in buffer; and 3) beta-TCP + buffer (active control). Safety data were assessed by the frequency and severity of adverse events. Effectiveness measurements included clinical attachment levels (CAL) and gingival recession (GR) measured clinically and linear bone growth (LBG) and percent bone fill (% BF) as assessed radiographically by an independent centralized radiology review center. The area under the curve (AUC), an assessment of the rate of healing, was also calculated for CAL measurements. The surgeons, clinical and radiographic evaluators, patients, and study sponsor were all masked with respect to treatment groups. RESULTS: CAL gain was significantly greater at 3 months for group 1 (rhPDGF 0.3 mg/ml) compared to group 3 (beta-TCP + buffer) (3.8 versus 3.3 mm; P = 0.032), although by 6 months, this finding was not statistically significant (P = 0.11). This early acceleration of CAL gain led to group 1 exhibiting a significantly greater rate of CAL gain between baseline and 6 months than group 3 as assessed by the AUC (68.4- versus 60.1-mm weeks; P = 0.033). rhPDGF (0.3 mg/ml)-treated sites also had significantly greater linear bone gain (2.6 versus 0.9 mm, respectively; P < 0.001) and percent defect fill (57% versus 18%, respectively; P < 0.001) than the sites receiving the bone substitute with buffer at 6 months. There was less GR at 3 months in group 1 compared to group 3 (P = 0.04); at 6 months, GR for group 1 remained unchanged, whereas there was a slight gain in gingival height for group 3 resulting in comparable GR. There were no serious adverse events attributable to any of the treatments. CONCLUSIONS: To our knowledge, this study is the largest prospective, randomized, triple-blinded, and controlled pivotal clinical trial reported to date assessing a putative periodontal regenerative and wound healing therapy. The study demonstrated that the use of rhPDGF-BB was safe and effective in the treatment of periodontal osseous defects. Treatment with rhPDGF-BB stimulated a significant increase in the rate of CAL gain, reduced gingival recession at 3 months post-surgery, and improved bone fill as compared to a beta-TCP bone substitute at 6 months.

A systematic review of observational studies evaluating implant placement in the maxillary jaws of medically compromised patients.

BACKGROUND: Even though the efficacy of implant treatment and the excellent success rates that modern implant surfaces yield remain unchallenged, there is limited information available on implant success rates in medically compromised patients. PURPOSE: The aim of this systematic review was to evaluate the survival of implants placed in the maxillary jaws of medically compromised patients. MATERIALS AND METHODS: Two reviewers using predefined selection criteria performed an electronic search complemented by a manual search, independently and in duplicate. RESULTS: After the final selection, 11 studies reporting on four distinct medical conditions were included out of 405 potentially eligible titles. In detail, three studies reported on implants placed in diabetic patients, six on implants placed in patients with a history of oral cancer, one on implants in patients with a history of epilepsy, and one on implants in patients with autoimmune rheumatoid arthritis. CONCLUSIONS: Placement of maxillary implants in medically compromised patients seems to yield acceptable survival rates. Implant survival in well-controlled diabetic patients, patients diagnosed with rheumatoid arthritis, and patients treated for severe epilepsy is comparable to that in healthy patients. Implants placed in the maxillae of patients treated for oral cancer may attain osseointegration less predictably than in the mandible.

Impact of cigarette smoking on clinical outcomes of periodontal flap surgical procedures: a systematic review and meta-analysis.

BACKGROUND: Periodontal flap surgery is frequently used to remove subgingival deposits, yielding consequential reductions in gingival inflammation and probing depth (PD) with a gain in clinical attachment level (CAL) to treat advanced periodontal disease. However, clinical studies have reported diminished periodontal healing in smokers compared with non-smokers. The aim of the present systematic review and meta-analysis was to assess the impact of cigarette smoking on clinical outcomes following periodontal flap surgical procedures. METHODS: A systematic electronic review of articles relevant to periodontal flap surgical procedures in smokers was conducted from 1977 to March 2014 inclusive, using predefined, optimized search strategies. Meta-analyses were done separately for changes in the two primary outcomes of PD and CAL. RESULTS: The initial search yielded 390 titles and abstracts. After screening, eight controlled clinical studies were finally selected. Three studies were assessed as having a low risk of bias, two as having moderate risk of bias, and three as having a high risk of bias. Qualitative assessment of the articles consistently showed an improved treatment effect among non-smokers versus smokers. The reduction in PD in smokers and non-smokers ranged from 0.76 to 2.05 mm and 1.27 to 2.40 mm, respectively. For CAL, the gain in non-smokers versus smokers ranged from 0.29 to 1.6 mm and 0.09 to 1.2 mm, respectively. Meta-analysis on eight studies reporting on 363 study participants demonstrated an increased reduction in mean (95% confidence interval) PD of 0.39 (0.33 to 0.45) mm. Similar results were found for mean gain in CAL (0.35 [0.30 to 0.40] mm, n = 4 studies). CONCLUSIONS: Considering the relatively homogenous information available, the authors conclude that active smokers could be candidates for periodontal flap surgical procedures. However, the magnitude of the therapeutic effect is compromised in smokers compared with non-smokers. Therefore, cigarette smokers should be: 1) encouraged to abstain from smoking; and 2) thoroughly informed preoperatively of substantial reduction in clinical outcomes compared with non-smokers.

Soft Tissue Surgical Procedures for Optimizing Anterior Implant Esthetics.

Implant dentistry has been established as a predictable treatment with excellent clinical success to replace missing or nonrestorable teeth. A successful esthetic implant reconstruction is predicated on two fundamental components: the reproduction of the natural tooth characteristics on the implant crown and the establishment of soft tissue housing that will simulate a healthy periodontium. In order for an implant to optimally rehabilitate esthetics, the peri-implant soft tissues must be preserved and/or augmented by means of periodontal surgical procedures. Clinicians who practice implant dentistry should strive to achieve an esthetically successful outcome beyond just osseointegration. Knowledge of a variety of available techniques and proper treatment planning enables the clinician to meet the ever-increasing esthetic demands as requested by patients. The purpose of this paper is to enhance the implant surgeon's rationale and techniques beyond that of simply placing a functional restoration in an edentulous site to a level whereby an implant-supported restoration is placed in reconstructed soft tissue, so the site is indiscernible from a natural tooth.

Prognostic factors in periodontal therapy and their association with treatment outcomes.

During the incipient steps of periodontal treatment, clinicians are usually asked to predict the prognosis of teeth with compromised periodontium. The aim of this literature review was to investigate the association between periodontal Prognosis, Tooth Loss and risk indicators, such as smoking and genetics. Results showed that the definition of good prognosis has much higher predictability than the one for questionable prognosis. Several risk indicators for periodontal prognosis and tooth loss are discussed as well as different definitions of questionable prognosis and their success in predicting tooth loss. In conclusion, the major focus of future studies should be to construct simplified prognostic models with high predictability that will increase the confidence of dentists and periodontists when assigning teeth prognosis.

A randomized, blinded, controlled clinical study of particulate anorganic bovine bone mineral and calcium phosphosilicate putty bone substitutes for socket preservation.

PURPOSE: The purpose of this study was to compare the clinical efficacy of an anorganic bovine bone graft particulate to that of a calcium phosphosilicate putty alloplast for socket preservation. MATERIALS AND METHODS: Thirty teeth were extracted from 24 patients. The sockets were debrided and received anorganic bovine bone mineral (BOV, n=12), calcium phosphosilicate putty (PUT, n=12), or no graft (CTRL, n=6). The sockets were assessed clinically and radiographically 5 months later. Eight sockets in the BOV group and nine in the PUT group received implants 5 to 6 months postgrafting. The maximum implant insertion torque (MIT) was measured as an index of primary implant stability. The data were analyzed with the Mann-Whitney test. RESULTS: Both test groups had statistically significantly less reduction in mean ridge width (BOV: 1.39±0.57 mm; PUT: 1.26±0.41 mm) in comparison to the control group (2.53±0.59 mm). No statistically significant difference was identified between the test groups. MIT for PUT was ≤35 N/cm² (MIT grade 4) for seven of the nine implants. MIT values in the BOV group ranged from grade 1 (10 to 19 N/cm²) to grade 4, which was statistically significantly lower than for the PUT group. The overall implant success rate was 94.1% (16 of 17 implants were successful). No implants were lost in the PUT group; one implant failed in the BOV group. CONCLUSION: Both tested bone substitutes can be recommended for preservation of alveolar ridge width following extraction. PUT might be more suitable for achieving primary stability for implants placed at 5 to 6 months postextraction.

Prevalence of maxillary midline papillae recession and association with interdental smile line: a cross-sectional study.

The objectives of this study were to record the prevalence and degree of absence of the maxillary midline interdental papilla and the proportion of patients displaying the maxillary midline papilla during maximum smile among a Caucasian population. Papillary recession was found in 46.4% of study participants (n = 211), while the prevalence of visible recession among maxillary midline papilla during maximum smile was 38.4%, which was statistically significantly less than that of patients diagnosed intraorally with loss of papillary height (P < .001). Correlations between age and level of lip line as well as age and visible papillary recession were identified for individuals over 65 years of age. The high prevalence of midline papillary recession in the maxilla found in this population suggests that loss of papillary height constitutes a substantial clinical challenge.

Platelet-derived growth factor promotes periodontal regeneration in localized osseous defects: 36-month extension results from a randomized, controlled, double-masked clinical trial.

BACKGROUND: Recombinant human platelet-derived growth factor (rhPDGF) is safe and effective for the treatment of periodontal defects in short-term studies up to 6 months in duration. We now provide results from a 36-month extension study of a multicenter, randomized, controlled clinical trial evaluating the effect and long-term stability of PDGF-BB treatment in patients with localized severe periodontal osseous defects. METHODS: A total of 135 participants were enrolled from six clinical centers for an extension trial. Eighty-three individuals completed the study at 36 months and were included in the analysis. The study investigated the local application of ß-tricalcium phosphate scaffold matrix with or without two different dose levels of PDGF (0.3 or 1.0 mg/mL PDGF-BB) in patients possessing one localized periodontal osseous defect. Composite analysis for clinical and radiographic evidence of treatment success was defined as percentage of cases with clinical attachment level (CAL) ≥2.7 mm and linear bone growth (LBG) ≥1.1 mm. RESULTS: The participants exceeding this composite outcome benchmark in the 0.3 mg/mL rhPDGF-BB group went from 62.2% at 12 months, 75.9% at 24 months, to 87.0% at 36 months compared with 39.5%, 48.3%, and 53.8%, respectively, in the scaffold control group at these same time points (P <0.05). Although there were no significant increases in CAL and LBG at 36 months among all groups, there were continued increases in CAL gain, LBG, and percentage bone fill over time, suggesting overall stability of the regenerative response. CONCLUSION: PDGF-BB in a synthetic scaffold matrix promotes long-term stable clinical and radiographic improvements as measured by composite outcomes for CAL gain and LBG for patients possessing localized periodontal defects ( ClinicalTrials.gov no. CT01530126).

Potential damage to bone-implant interface when measuring initial implant stability.

BACKGROUND: An electronically controlled mechanical tapping device (MTD) to measure implant stability has been studied extensively for its ability to measure initial stability at the time of surgical placement and predict an implant's survival prognosis, with few reported complications. METHODS: Initial stability data, measured repeatedly with a resonance frequency analysis device and the MTD, for seven of 28 implants placed in jawbones of four fresh human cadavers and the histologic images of bone-implant interfaces are presented as evidence for potential damage to the bone-implant interface using these techniques. RESULTS: A progressive increase in mobility from stable (-1) to less stable (4) and eventually to visibly mobile (999) was observed after three measurements with the MTD. Corresponding histologic images revealed that the buccal threads in the coronal half of the implants were displaced lingually and apically from the bony indentations that were created during insertion of the self-threading implants, subsequent to repeated MTD measurements in the buccal and axial directions. The histologic images and changes in MTD values indicated that repeated MTD measurements at the time of implant placement surgery may damage the bone-implant interface, and a stable or borderline implant may become mobile after repeated MTD measurements. CONCLUSIONS: Histologic images showed potential damage to the bone-implant interface during repeated initial implant-stability measurements using the MTD. Initial implant-stability measurements using the MTD should be performed with caution, and they may be contraindicated for implants placed in low-quality bone.

Histologic evaluation of demineralized freeze-dried bone allografts in barrier membrane covered periodontal fenestration wounds and ectopic sites in dogs.

BACKGROUND/AIM: The aim of this study was to investigate healing responses to demineralized freeze-dried bone powder allografts in standardized periodontal fenestration defects, compared with subcutaneous wounds in a dog model. METHODS: Circular periodontal fenestration defects were created buccally at all four canines in 14 mongrel dogs. Each site received one of the following underneath a barrier membrane: (a) ethylene oxide (EO)-sterilized demineralized freeze-dried bone allografts (DFDBA), (b) heat-treated DFDBA, (c) non-sterilized DFDBA and (d) ungrafted control. Twelve of the 14 dogs had three subcutaneous chest wall pouches created and one of the three DFDBA materials placed in each. The animals were necropsied at 4 weeks. Histologic sections were prepared through the center of the fenestration sites in an apico-coronal direction. Quantitative analysis using computer-assisted imaging technique was performed. Subcutaneous implants were evaluated histologically and quantified for associated inflammatory cell infiltrate. RESULTS: Fenestration defects healed by partial osseous fill and cementum regeneration with formation of a periodontal ligament. The graft particles generally appeared isolated from the site of osteogenesis and covered by cementum-like substance. Graft particles incorporated into newly formed bone at a distance from the root surface was the exception. No statistically significant differences in new bone formation were observed between treatment groups within animals, but significant inter-animal variation was found (p<0.01). Quantities of retained graft particles were limited, and without cellular resorption. A bone augmentation effect was associated with the barrier in the majority of sites. No bone formation was evident at the subcutaneous sites where graft particles displayed distinctly modified surface zones and multinucleated giant cell resorption. Significantly more inflammatory infiltrate was associated with EO-sterilized grafts compared with heat-treated grafts (p=0.05). CONCLUSION: Implantation of DFDBA neither enhanced osseous healing in periodontal fenestration defects, nor resulted in ectopic bone induction. DFDBA particles implanted in either periodontal fenestration or subcutaneous wounds evoked distinctly different healing responses.