371 research outputs found
Bone regeneration in implant dentistry: Which are the factors affecting the clinical outcome?
The key factors that are needed for bone regeneration to take place include cells (osteoprogenitor and immune-inflammatory cells), a scaffold (blood clot) that facilitates the deposition of the bone matrix, signaling molecules, blood supply, and mechanical stability. However, even when these principles are met, the overall amount of regenerated bone, its stability over time and the incidence of complications may significantly vary. This manuscript provides a critical review on the main local and systemic factors that may have an impact on bone regeneration, trying to focus, whenever possible, on bone regeneration simultaneous to implant placement to treat bone dehiscence/fenestration defects or for bone contouring. In the future, it is likely that bone tissue engineering will change our approach to bone regeneration in implant dentistry by replacing the current biomaterials with osteoinductive scaffolds combined with cells and mechanical/soluble factors and by employing immunomodulatory materials that can both modulate the immune response and control other bone regeneration processes such as osteogenesis, osteoclastogenesis, or inflammation. However, there are currently important knowledge gaps on the biology of osseous formation and on the factors that can influence it that require further investigation. It is recommended that future studies should combine traditional clinical and radiographic assessments with non-invasive imaging and with patient-reported outcome measures. We also envisage that the integration of multi-omics approaches will help uncover the mechanisms responsible for the variability in regenerative outcomes observed in clinical practice
Soft tissue augmentation procedures at second-stage surgery: a systematic review.
OBJECTIVES
The aim of this systematic review was to evaluate the efficacy of different soft tissue augmentation/correction methods in terms of increasing the peri-implant width of keratinized mucosa (KM) and/or gain of soft tissue volume during second-stage surgery.
MATERIALS AND METHODS
Screening of two databases, MEDLINE (PubMed) and EMBASE (OVID), and hand search of related articles, were performed. Human studies reporting on soft tissue augmentation/correction methods around submucosally osseointegrated implants during second-stage surgery up to July 31, 2015 were considered. Quality assessment of the selected full-text articles was performed according to the Cochrane collaboration's tool to assess the risk of bias.
RESULTS
Overall, eight prospective studies (risk of bias: high) and two case series (risk of bias: high) were included. Depending on the surgical technique and graft material used, the enlargement of keratinized tissue (KT) ranged between -0.20 and 9.35Â mm. An apically positioned partial-thickness flap/vestibuloplasty (APPTF/VP) in combination with a free gingival graft (FGG) or a xenogeneic graft material (XCM) was most effective. Applying a roll envelope flap (REF) or an APPTF in combination with a subepithelial connective tissue graft (SCTG), mean increases in soft tissue volumes of 2.41 and 3.10Â mm, respectively, were achieved. Due to the heterogeneity of study designs, no meta-analysis could be performed.
CONCLUSIONS
Within the limitations of this review, regarding the enlargement of peri-implant KT, the APPTF in the maxilla and the APPTF/VP in combination with FGG or XCM in the lower and upper jaw seem to provide acceptable outcomes. To augment peri-implant soft tissue volume REF in the maxilla or APPTFÂ +Â SCTG in the lower and upper jaw appear to be reliable treatment options.
CLINICAL RELEVANCE
The localization in the jaw and the clinical situation are crucial for the decision which second-stage procedure should be applied
Efficacy of tunnel technique in the treatment of localized and multiple gingival recessions: A systematic review and metaâ analysis
BackgroundTunnel technique (TUN) has recently gained popularity among clinicians for its promising clinical and esthetic results in treating gingival recession (GR) defects. However, evidence regarding the efficacy of the TUN is not yet conclusive. Therefore, the aim of the present systematic review and metaâ analysis was to investigate the predictability of TUN and its comparison to the coronally advanced flap (CAF) procedure.MethodsA literature search on PubMed, Cochrane libraries, EMBASE, and handâ searched journals through November 2017 was conducted to identify clinical studies investigating TUN for root coverage procedures. Only randomized controlled trials (RCTs) were considered for the metaâ analysis comparing TUN to CAF.ResultsA total of 20 articles were included in the systematic review and six in the metaâ analysis. The overall calculated mean root coverage (mRC) of TUN for localized and multiple GR defects was 82.75 ± 19.7% and 87.87 ± 16.45%, respectively. Superior results were found in maxillary and in Miller Class I and II GR defects. TUN outcomes may have been enhanced by splitâ thickness flap preparation and microsurgical approach. TUN and CAF had comparable mRC, complete root coverage (CRC), keratinized tissue gain, and root coverage esthetic score when varying combinations of graft material were evaluated. However, CAF demonstrated superior outcomes to TUN when the same graft (connective tissue or acellular dermal matrix) was used in both techniques.ConclusionsTUN is an effective procedure in treating localized and multiple GR defects. Limited evidence is available comparing TUN to CAF; however, CAF seemed to be associated with higher percentage of CRC than was TUN when the same grafts (connective tissue or acellular dermal matrix) were used in both techniques.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145520/1/jper10154.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145520/2/jper10154_am.pd
Efficacy of biomaterials for lateral bone augmentation performed with guided bone regeneration. A network meta-analysis.
Bone regeneration is often required concomitant with implant placement to treat a bone fenestration, a dehiscence, and for contouring. This systematic review assessed the impact of different biomaterials employed for guided bone regeneration (GBR) simultaneous to implant placement on the stability of radiographic peri-implant bone levels at ≥12 months of follow-up (focused question 1), as well as on bone defect dimension (width/height) changes at re-assessment after ≥4 months (focused question 2). Only randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that compared different biomaterials for GBR were considered. A Bayesian network meta-analysis (NMA) was performed using a random-effects model. A ranking probability between treatments was obtained, as well as an estimation of the surface under the cumulative ranking value (SUCRA). Overall, whenever the biological principle of GBR was followed, regeneration occurred in a predictable way, irrespective of the type of biomaterial used. A lower efficacy of GBR treatments was suggested for initially large defects, despite the trend did not reach statistical significance. Regardless of the biomaterial employed, a certain resorption of the augmented bone was observed overtime. While GBR was shown to be a safe and predictable treatment, several complications (including exposure, infection, and soft tissue dehiscence) were reported, which tend to be higher when using cross-linked collagen membranes
In vitro proliferation of human osteogenic cells in presence of different commercial bone substitute materials combined with enamel matrix derivatives
<p>Abstract</p> <p>Background</p> <p>Cellular reactions to alloplastic bone substitute materials (BSM) are a subject of interest in basic research. In regenerative dentistry, these bone grafting materials are routinely combined with enamel matrix derivatives (EMD) in order to additionally enhance tissue regeneration.</p> <p>Materials and methods</p> <p>The aim of this study was to evaluate the proliferative activity of human osteogenic cells after incubation over a period of seven days with commercial BSM of various origin and chemical composition. Special focus was placed on the potential additional benefit of EMD on cellular proliferation.</p> <p>Results</p> <p>Except for PerioGlas<sup>®</sup>, osteogenic cell proliferation was significantly promoted by the investigated BSM. The application of EMD alone also resulted in significantly increased cellular proliferation. However, a combination of BSM and EMD resulted in only a moderate additional enhancement of osteogenic cell proliferation.</p> <p>Conclusion</p> <p>The application of most BSM, as well as the exclusive application of EMD demonstrated a positive impact on the proliferation of human osteogenic cells <it>in vitro</it>. In order to increase the benefit from substrate combination (BSM + EMD), further studies on the interactions between BSM and EMD are needed.</p
Treatment of multiple adjacent RT 1 gingival recessions with the modified coronally advanced tunnel (MCAT) technique and a collagen matrix or palatal connective tissue graft: 9-year results of a split-mouth randomized clinical trial.
OBJECTIVES
To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with either a collagen matrix CM or a connective tissue graft (CTG).
MATERIAL AND METHODS
Sixteen of the original 22 subjects included in a randomized, controlled split-mouth clinical trial were available for the 9-year follow-up (114 sites). Recessions were randomly treated by means of MCAT + CM (test) or MCAT + CTG (control). Complete root coverage (CRC), mean root coverage (MRC), gingival recession depth (GRD), probing pocket depth (PD), keratinized tissue width (KTW), and thickness (KGT) were compared with baseline values and with the 12-month results.
RESULTS
After 9 years, CRC was observed in 2 patients, one in each group. At 9 years, MRC was 23.0 ± 44.5% in the test and 39.7 ± 35.1% in the control group (p = 0.179). The MRC reduction compared to 12 months was - 50.1 ± 47.0% and - 48.3 ± 37.7%, respectively. The upper jaw obtained 31.92 ± 43.0% of MRC for the test and 51.1 ± 27.8% for the control group (p = 0.111) compared to the lower jaw with 8.3 ± 46.9% and 20.7 ± 40.3%. KTW and KGT increased for both CM and CTG together from 2.0 ± 0.7 to 3.1 ± 1.0 mm (< 0.0001). There were no statistically significant changes in PD.
CONCLUSION
The present results indicate that (a) treatment of MAGR using MCAT in conjunction with either CM or CTG is likely to show a relapse over a period of 9Â years, and (b) the outcomes obtained in maxillary areas seem to be more stable compared to the mandibular ones.
CLINICAL RELEVANCE
The mean root coverage at 12Â months could not be fully maintained over 9Â years. On a long-term basis, the results seem to be less stable in the mandible as compared to maxillary areas
Adjunctive laser or antimicrobial photodynamic therapy to non-surgical mechanical instrumentation in patients with untreated periodontitis. A systematic review and meta-analysis.
AIM
To compare the adjunctive effects of lasers or antimicrobial photodynamic therapy (aPDT) to non-surgical mechanical instrumentation alone in untreated periodontitis patients.
MATERIALS AND METHODS
Two focused questions were addressed using the Population, Intervention, Comparison and Outcome criteria as follows: in patients with untreated periodontitis, i) does laser application provide adjunctive effects on probing pocket depth (PPD) changes compared with non-surgical instrumentation alone? and ii) does application of aPDT provide adjunctive effects on PPD changes compared with non-surgical instrumentation alone? Both randomized controlled clinical trials (RCTs) and controlled clinical trials (CCTs) were included. Results of the meta-analysis are expressed as weighted mean differences (WMD) and reported according to the PRISMA guidelines.
RESULTS
Out of 1'202 records, 10 articles for adjunctive laser and 8 for adjunctive aPDT were included. With respect to PPD changes, 1 meta-analysis including 2 articles (total n = 42; split-mouth design) failed to identify a statistically significant difference (WMD = 0.35 mm; 95%CI:-0.04/0.73; p = .08) in favour of adjunctive aPDT (wavelength range 650-700 nm). In terms of adjunctive laser application a high variability of clinical outcomes at 6 months was noted. Two articles included patient-reported outcomes and 10 reported on the presence/absence of harms/adverse effects.
CONCLUSIONS
Available evidence on adjunctive therapy with lasers and aPDT is limited by (i) the low number of controlled studies and (ii) the heterogeneity of study designs. Patient-reported benefits remain to be demonstrated
Recession coverage using the modified coronally advanced tunnel and connective tissue graft with or without enamel matrix derivative: 5-year results of a randomised clinical trial.
OBJECTIVES
To evaluate the 5-year results of single and multiple recession type (RT) 1 and 2 (Miller I to III) recessions treated with the modified coronally advanced tunnel (MCAT) and connective tissue graft (CTG) with or without an enamel matrix derivative (EMD). The main outcome variable was the stability of obtained root coverage from 6Â months to 5Â years.
MATERIALS AND METHODS
In 24 patients, both complete and mean root coverage (CRC and MRC) and gain of keratinised tissue (KT) were assessed at 6Â months and 5Â years after recession coverage by means of MCAT and CTG with or without EMD. Aesthetic outcomes after 5Â years were evaluated using the root coverage aesthetic score (RES).
RESULTS
At 5 years, 24 patients with a total of 43 recessions were evaluated. Eight patients (57.14%) of the test and 6 (60.0%) of the control group showed complete root coverage. MRC revealed no statistically significant differences between the two groups, with 73.87 ± 26.83% (test) and 75.04 ± 22.06% (control), respectively. KT increased from 1.14 ± 0.57 mm to 3.07 ± 2.27 mm in the test group and from 1.24 ± 0.92 mm to 3.02 ± 1.55 mm in the control group, respectively.
CONCLUSION
Treatment of single and multiple RT 1 and 2 recessions by means of MCAT and CTG with or without EMD yielded comparable clinical improvements which could be maintained over a period of 5Â years. The additional use of EMD did not influence the clinical outcomes.
CLINICAL RELEVANCE
The use of MCAT + CTG yielded successful coverage of single and multiple RT 1 and 2 gingival recessions, while the additional application of EMD did not seem to influence the results
Reconstructive periodontal therapy with simultaneous ridge augmentation. A clinical and histological case series report
Treatment of intrabony periodontal defects with a combination of a natural bone mineral (NBM) and guided tissue regeneration (GTR) has been shown to promote periodontal regeneration in intrabony defects. In certain clinical situations, the teeth presenting intrabony defects are located at close vicinity of the resorbed alveolar ridge. In these particular cases, it is of clinical interest to simultaneously reconstruct both the intrabony periodontal defect and the resorbed alveolar ridge, thus allowing insertion of endosseous dental implants. The aim of the present study was to present the clinical and histological results obtained with a new surgical technique designed to simultaneously reconstruct the intrabony defect and the adjacently located resorbed alveolar ridge. Eight patients with chronic advanced periodontitis displaying intrabony defects located in the close vicinity of resorbed alveolar ridges were consecutively enrolled in the study. After local anesthesia, mucoperiosteal flaps were raised, the granulation tissue removed, and the roots meticulously scaled and planed. A subepithelial connective tissue graft was harvested from the palate and sutured to the oral flap. The intrabony defect and the adjacent alveolar ridge were filled with a NBM and subsequently covered with a bioresorbable collagen membrane (GTR). At 11–20 months (mean, 13.9 ± 3.9 months) after surgery, implants were placed, core biopsies retrieved, and histologically evaluated. Mean pocket depth reduction measured 3.8 ± 1.7 mm and mean clinical attachment level gain 4.3 ± 2.2 mm, respectively. Reentry revealed in all cases a complete fill of the intrabony component and a mean additional vertical hard tissue gain of 1.8 ± 1.8 mm. The histologic evaluation indicated that most NBM particles were surrounded by bone. Mean new bone and mean graft area measured 17.8 ± 2.8% and 32.1 ± 8.3%, respectively. Within their limits, the present findings indicate that the described surgical approach may be successfully used in certain clinical cases to simultaneously treat intrabony defects and to reconstruct the resorbed alveolar ridge
Spontaneous regeneration of keratinized tissue at implants and teeth.
AIM
To investigate the spontaneous regeneration of the implanto-mucosal and dento-gingival unit after complete removal of keratinized tissue (KT).
MATERIALS AND METHODS
One hemi-mandible per dog (n = 4) was allocated to receive three dental implants (test sites, premolar region), whereas three premolars on the contralateral side were controls. After osseointegration, the entire KT (buccal + lingual) was surgically excised on all test and control sites, leaving the bone exposed. Clinical measurements were performed before excision (T0 ) and after 12 weeks (T1 ). Following healing, the animals were euthanized, and the specimens were histologically processed. Descriptive statistical analyses were performed.
RESULTS
Clinical measurements revealed that at T1 , on all teeth, a band of KT was spontaneously regenerated (mean width: 2.60 ± 0.66 mm), whereas on implants, KT was detected only occasionally at mesial or distal but not at buccal sites (mean total: 0.35 ± 0.53 mm; p < .0001). Histologically, spontaneous regeneration of the dento-gingival unit was evident, displaying masticatory mucosa. At the implant sites, on the other hand, the implanto-mucosal unit was characterized by a non-keratinized epithelium and elastic fibres, indicating the characteristics encountered in alveolar mucosa.
CONCLUSION
After excision of KT at implant sites, the spontaneous regeneration of the soft tissue is characterized by a non-keratinized epithelium typical for alveolar mucosa, while at tooth sites the spontaneous regeneration was characterized by soft tissue resembling gingiva
- …