Comparative Efficacy of Different Flapless Ridge Preservation Techniques: A Systematic Review and Meta-Analysis.

Although the efficacy of ridge preservation is well documented, there is a lack of robust evidence regarding the influence of different surgical techniques. Flapless approaches are thought to be better at preserving soft tissue architecture and have been suggested for mild to moderate defects. This review investigates the efficacy of different flapless techniques for ridge preservation in mild to moderate defects with <50% buccal bone loss. PubMed, EMBASE, and Cochrane Library databases were searched to obtain relevant articles published in English from 1974 to December 2019. The primary outcome was horizontal and vertical hard tissue dimensional changes. Soft tissue changes were evaluated as a secondary outcome. The Bio-Col technique, subperiosteal tunnel technique, and hard tissue with autogenous soft tissue graft/collagen matrix technique were identified. Eight studies were included, and quantitative analyses were performed for 4 studies for the primary outcome variables. The meta-analysis revealed significant reductions for horizontal changes (weighted mean difference [WMD] = 2.56 mm, 95% CI [2.18, 2.95]), vertical mid-buccal (WMD = 1.47 mm, 95% CI [1.04, 1.90]), and vertical mid-lingual (WMD = 1.28 mm, 95% CI [0.68, 1.87]) in favor of flapless ridge preservation techniques. Subgroup analysis based on technique suggests minimal hard tissue differences. The efficacy of flapless ridge preservation techniques on soft tissue changes was inconclusive. In conclusion, flapless ridge preservation techniques are effective for mild to moderate defects. The technique or material used to close the extraction socket does not seem to significantly affect hard tissue changes, while the effect on soft tissue changes warrants further investigation.

Group 4 ITI Consensus Report: Risks and biologic complications associated with implant dentistry.

OBJECTIVES: The aim of Working Group 4 was to address topics related to biologic risks and complications associated with implant dentistry. Focused questions on (a) diagnosis of peri-implantitis, (b) complications associated with implants in augmented sites, (c) outcomes following treatment of peri-implantitis, and (d) implant therapy in geriatric patients and/or patients with systemic diseases were addressed. MATERIALS AND METHODS: Four systematic reviews formed the basis for discussion in Group 4. Participants developed statements and recommendations determined by group consensus based on the findings of the systematic reviews. These were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Bleeding on probing (BOP) alone is insufficient for the diagnosis of peri-implantitis. The positive predictive value of BOP alone for the diagnosis of peri-implantitis varies and is dependent on the prevalence of peri-implantitis within the population. For patients with implants in augmented sites, the prevalence of peri-implantitis and implant loss is low over the medium to long term. Peri-implantitis treatment protocols which include individualized supportive care result in high survival of implants after 5 years with about three-quarters of implants still present. Advanced age alone is not a contraindication for implant therapy. Implant placement in patients with cancer receiving high-dose antiresorptive therapy is contraindicated due to the associated high risk for complications. CONCLUSIONS: Diagnosis of peri-implantitis requires the presence of BOP as well as progressive bone loss. Prevalence of peri-implantitis for implants in augmented sites is low. Peri-implantitis treatment should be followed by individualized supportive care. Implant therapy for geriatric patients is not contraindicated; however, comorbidities and autonomy should be considered.

Rodent peri-implantitis models: a systematic review and meta-analysis of morphological changes.

PURPOSE: Rodent models have emerged as an alternative to established larger animal models for peri-implantitis research. However, the construct validity of rodent models is controversial due to a lack of consensus regarding their histological, morphological, and biochemical characteristics. This systematic review sought to validate rodent models by characterizing their morphological changes, particularly marginal bone loss (MBL), a hallmark of peri-implantitis. METHODS: This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A literature search was performed electronically using MEDLINE (PubMed), and Embase, identifying pre-clinical studies reporting MBL after experimental peri-implantitis induction in rodents. Each study's risk of bias was assessed using the Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias tool. A meta-analysis was performed for the difference in MBL, comparing healthy implants to those with experimental peri-implantitis. RESULTS: Of the 1,014 unique records retrieved, 23 studies that met the eligibility criteria were included. Peri-implantitis was induced using 4 methods: ligatures, lipopolysaccharide, microbial infection, and titanium particles. Studies presented high to unclear risks of bias. During the osseointegration phase, 11.6% and 6.4%-11.3% of implants inserted in mice and rats, respectively, had failed to osseointegrate. Twelve studies were included in the meta-analysis of the linear MBL measured using micro-computed tomography. Following experimental peri-implantitis, the MBL was estimated to be 0.25 mm (95% confidence interval [CI], 0.14-0.36 mm) in mice and 0.26 mm (95% CI, 0.19-0.34 mm) in rats. The resulting peri-implant MBL was circumferential, consisting of supra- and infrabony components. CONCLUSIONS: Experimental peri-implantitis in rodent models results in circumferential MBL, with morphology consistent with the clinical presentation of peri-implantitis. While rodent models are promising, there is still a need to further characterize their healing potentials, standardize experiment protocols, and improve the reporting of results and methodology. TRIAL REGISTRATION: PROSPERO Identifier: CRD42020209776.

Theory-derived intervention to improve oral health of older adults: study protocol for a randomised controlled trial.

INTRODUCTION: Changing health behaviours is an important and difficult task. Despite growing interest in behavioural theories and models, there is a paucity of research examining their validity in explaining oral health behaviours, and there is a need for interventional studies to assess their effectiveness in improving oral health. This study aims to test the explanatory power of the dominant psychological theories, develop theory-derived intervention and evaluate its effectiveness in improving oral health of older adults. METHODS AND ANALYSIS: 440 community dwelling older adults will be recruited. To be eligible for this trial, one needs to be 55-79 years old, having at least 8 natural teeth, and with no life-threatening disease, impaired cognitive function, or radiotherapy in the head and neck region. At the initial visit, each participant will be required to complete a detailed questionnaire which collects information on sociodemographic background, oral health behaviours and domains of three psychological theories and models: (1) health belief model, (2) theory of planned behaviour and (3) social cognitive theory. The theory or model that best explains the health behaviours will be selected for designing the oral health intervention. The effectiveness of the theory-derived intervention will be evaluated in a randomised controlled trial. Participants will be randomly assigned to two groups, receiving theory-derived intervention and conventional health education, respectively. At baseline and at 12 and 24 months post intervention, each participant will complete a short questionnaire and undergo an oral examination (dental check-up). The effectiveness of the interventions will be evaluated using behavioural outcomes (diet, toothbrushing, interdental cleaning) and clinical outcomes (oral hygiene, dental caries and periodontal conditions). ETHICS AND DISSEMINATION: This study has been approved by the Institutional Review Board of National University of Singapore (Ref: NUS-IRB-2020-417). Findings will be presented in international conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04946292.

Gingival profiles in a select Asian cohort: A pilot study.

AIM: The aim of the present study was to determine the facial gingival profiles of teeth with a healthy periodontium in an Asian population. METHODS: A total of 51 patients with a healthy periodontium were examined. Gingival thickness (GT) and gingival width (GW) were assessed at the maxillary and mandibular incisors to the first molars. GT was measured by transgingival probing (GT-TGP), and probe visibility through the marginal gingiva (GT-TRAN) was assessed. Results between groups (anterior and posterior, tooth types) were analyzed using one-way analysis of variance and t-test. RESULTS: The mean age was 30.3±11.4 years, with 27 females and 24 males. The mean GT-TGP was 1.39±52 mm, while the mean GW was 4.59±1.34 mm. Considerable intra-individual and interindividual variation in GT (TGP and TRAN) was noted. GT increased from the anterior to posterior, and was thinnest at the mandibular centrals to the first premolars and maxillary canines. GT-TGP and GW were influenced by tooth type, plaque, recession, and TRAN, but not age, sex, or ethnicity. GW were recorded lowest at the mandibular canines and all premolars. Thin gingiva was recorded at 63.8%-92% (GT-TGP<1.5 mm) and 75%-90% (GT-TRAN) of the anterior teeth. CONCLUSION: A high percentage of anterior teeth had thin marginal gingiva. There was poor agreement between GT-TGP and GT-TRAN.

Management strategies of the unsalvageable tooth.

UNLABELLED: A tooth is deemed unsalvageable when it can no longer be preserved for use of function or aesthetic purposes. If proper treatment planning is done, tooth extraction can be performed with adjunctive procedures, to provide a more predictable restorative outcome for the patient. This review paper summarizes the possible treatment strategies available for the management of a tooth with a poor prognosis, so as to manage the patient better before the restorative treatment phase commences. CLINICAL RELEVANCE: The management of an unsalvageable tooth using interdisciplinary approaches offers the clinician strategies for providing a more favourable restorative outcome.

Campylobacter rectus mediates growth restriction in pregnant mice.

BACKGROUND: Recent studies have suggested that subclinical infection may be an important cause of low birth weight. Campylobacters are important human pathogens, causing septicemia and occasionally abortion, premature labor, or severe perinatal infection. The potential role of oral species of Campylobacter in mediating adverse pregnancy outcomes in animal models has not yet been determined. Our objective was to determine the effects of Campylobacter rectus (C. rectus) infection on pregnancy outcomes in a mouse model. METHODS: On embryonic day (E) 7.5, pregnant mice received a subcutaneous, intra-chamber challenge with live C. rectus at concentrations of 0, 10(7) or 10(9) colony forming units (CFU)/ml. They were sacrificed on E 16.5 and fetuses were evaluated for stage of development, weight, and crown-rump length. RESULTS: Dams receiving C. rectus had more fetal resorptions after challenge with 10(7) or 10(9) CFU/ml (24.1% and 30.1%, respectively) than controls (9%). Higher numbers of growth-restricted fetuses were also observed in the C. rectus challenged groups (21%) as compared to controls (2.3%). Fetuses from dams challenged with 10(9) CFU/ml weighed less (0.49 +/- 0.05 g) and had shorter crown-rump lengths (14.69 +/- 0.56 mm) than controls (0.53 +/- 0.04 g; 15.54 +/- 0.63 mm). C. rectus was detected by polymerase chain reaction (PCR) in the placentas from both treated groups and in maternal liver tissues from the 10(9) CFU/ml challenged group. CONCLUSIONS: Remote subcutaneous maternal C. rectus infection increases fetal resorptions and fetal growth restriction in a mouse model. The effects of an oral C. rectus infection on pregnancy remain to be determined.

Principles and implications of site preservation for alveolar ridge development.

The extraction of a tooth normally results in the loss of ridge height and width. Often, clinicians are faced with the management of edentulous sites that are less than optimal for prosthetic rehabilitation and implant restoration due to considerable alveolar ridge collapse after tooth removal. Site preservation using bone grafts or substitutes with and without a membrane maintain ridge dimensions and contours. However, some clinicians believe that such procedures are over-treatment. This paper reviews the concepts and indications for site preservation following tooth extraction for the purpose of facilitating implant placement and conventional prosthetic restoration.

Surface modification of PCL-TCP scaffolds in rabbit calvaria defects: Evaluation of scaffold degradation profile, biomechanical properties and bone healing patterns.

Traditionally, polycaprolactone (PCL) based scaffolds tend to degrade at a slow rate. Pretreatment of polycaprolactone-20% tricalcium phosphate (PCL-TCP) scaffolds under alkaline conditions can be utilized to increase the degradation rate and improve mechanical properties. Three groups of PCL-TCP scaffolds with varying pretreatment exposures with sodium hydroxide (NaOH) were studied in a rabbit calvaria defect model and analyzed at 2, 4, 8, 12, and 24 weeks. (Group A: Untreated, Group B: 3 M NaOH/ 48 h and Group C: 3 M NaOH/96 h). Micro-CT analysis demonstrated that scaffolds with increased surface roughness (Groups B and C) showed a greater impact on the overall volume loss during the early healing period between 2 and 8 weeks as compared to the untreated group. In addition, greater bone formation was detected in NaOH treated scaffolds as compared to the untreated group throughout the experiment. Scaffolds with increased surface roughness generally reported higher push out test and compressive strength values from 4 to 8 weeks of early healing. Interestingly, the mechanical properties displayed a decline in values from 12 weeks onwards in the modified groups suggesting a favorable breakdown or weakening of PCL-TCP scaffolds tailored for replacement by new bone formation.

Customizing the degradation and load-bearing profile of 3D polycaprolactone-tricalcium phosphate scaffolds under enzymatic and hydrolytic conditions.

The degradation of polycaprolactone-20% tricalcium phosphate (PCL-TCP) scaffolds was customized for dentoalveolar augmentation applications, where 5-6 months period is optimal. The scaffolds were treated with either 3M sodium hydroxide (NaOH) or 0.1% lipase solution for a total of 108 h. A greater degree of degradation and reduction in the physical properties of the scaffolds was observed in the lipase treated when compared with NaOH-treated scaffolds. After 108 h, increases in weight loss and average porosity of the scaffolds in the lipase-treated group measured 90.6% and 22.9%, respectively, when compared with 52.8% and 11.8% in the NaOH-treated group. The mechanical testing results revealed a similar trend, with a complete loss of compressive strength and modulus measured as early as 60 h in the lipase-treated group. The honeycomblike architecture was well preserved throughout the experiment only for the NaOH-treated scaffolds in addition to a favorable surface roughness ideal for bone-regeneration applications. In conclusion, pretreatment with NaOH demonstrates a simple approach for tailoring the physical properties and degradation rate of PCL-TCP scaffolds for the potential use as biomaterials targeted for dentoalveolar bone-regeneration procedures.

Evaluation of a novel biphasic calcium phosphate in standardized bone defects: a histologic and histomorphometric study in the mandibles of minipigs.

OBJECTIVE: A novel biphasic calcium phosphate (CaP) granulate consisting of hydroxyapatite (HA) and beta-tricalciumphosphate (TCP) was compared with pure HA and pure TCP and with autograft as positive control. MATERIALS AND METHODS: Four standardized bone defects were prepared in both mandibular angles of 16 minipigs and grafted with autogenous bone chips, HA, HA/TCP (60% : 40%), or TCP. Histologic and histomorphometric analysis of bone formation and graft degradation followed healing periods of 2, 4, 8, and 24 weeks. RESULTS: 2 weeks: more bone formation in defects filled with autograft than with the three CaP materials (P<0.05). 4 weeks: bone formation differed significantly (P<0.05) between all four materials (autograft>TCP>HA/TCP>HA). 8 weeks: more bone formation in defects with autograft and TCP than with HA/TCP (P<0.05), and HA/TCP had more bone formation than HA (P<0.05). 24 weeks: no difference in bone formation between the groups. Autograft and TCP resorbed quickly and almost completely over 8 weeks, whereas HA/TCP and HA showed limited degradation over 24 weeks. CONCLUSION: All defects healed with mature lamellar bone and intimate contact between bone and the remaining graft material. The rate of bone formation corresponded to the content of TCP in the CaP materials.