Risk factors for tooth loss and progression of periodontitis in patients undergoing periodontal maintenance therapy.

AIM: The aim of this study was to investigate patient- and tooth-level factors that may predict tooth loss and periodontitis progression in patients who have undergone at least 5 years of periodontal maintenance. MATERIALS AND METHODS: In this retrospective cohort study, 135 patients were examined after active periodontal therapy (APT) and periodontal maintenance for 5.09-8.65 years (mean 6.16 ± 0.74 years). Regression models were applied to identify risk factors associated with tooth loss and disease progression. RESULTS: Stage IV periodontitis (incidence rate ratio [IRR] = 4.61; 95% confidence interval, CI [2.97-7.18], p < .001), the presence of ≥5 sites with probing pocket depth (PPD) ≥5 mm at the end of APT (IRR = 2.04; 95% CI [1.32-3.20], p < .01), and residual PPD ≥7 mm at the end of APT (odds ratio [OR] = 3.01; 95% CI [1.14-7.94], p < .05) were risk factors for tooth loss. Residual PPDs of 5 mm (OR = 2.02; 95% CI [1.20-3.40], p < .01) and 6 mm (OR = 2.41; 95% CI [1.22-4.76], p < .05) at the end of APT were risk factors for disease progression. Above 3 mm, each 1 mm increase in maximum PPD/clinical attachment loss was associated with an increased risk of tooth loss and disease progression. CONCLUSIONS: Stage IV periodontitis is associated with an increased risk of tooth loss. Teeth with PPD ≥5 mm at the end of APT are at risk of periodontitis progression or tooth loss.

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.

The efficacy of probiotics in the management of intra-oral halitosis: a systematic review.

OBJECTIVES: To evaluate the efficacy of probiotics in reducing halitosis of dental origin. METHODS: MEDLINE, EMBASE, and CENTRAL were searched up to and including June 2020. Randomised placebo-controlled, double-blinded clinical trials in systemically healthy adult patients who were given any form of probiotics to manage halitosis of dental origin were included. Primary outcome measures were organoleptic scores and volatile sulphur concentration levels. Secondary outcome measures were microbiologic parameters and quality of life (QOL). RESULTS: Of the 301 potentially relevant articles, eight articles were selected for the review. The risk of bias assessment showed that two studies were of low risk of bias, four studies had some concerns, and two studies had a high risk of bias. The beneficial effect of probiotics could neither be confirmed in periodontally treated patients administered with up to 8 weeks of probiotics, nor in periodontitis patients who received both non-surgical periodontal therapy and adjunctive probiotics up to 90 days. Microbiological findings 1 month after probiotics administration and QOL measures showed no significant differences compared to control. Considerable heterogeneity was observed among probiotic administration protocols. CONCLUSIONS: The available evidence suggests no convincing benefit for the use of probiotics in the management of halitosis. Standardised protocols on recruitment of halitosis subjects and organoleptic measurements are required for future studies on probiotics as an intervention. CLINICAL RELEVANCE: The lack of well-conducted studies with a low risk of bias precludes any clinical recommendation. Further research is needed to verify the efficacy of probiotics in the management of intra-oral halitosis.

Adjunctive probiotics after periodontal debridement versus placebo: a systematic review and meta-analysis.

OBJECTIVE: To comprehensively investigate the efficacy of adjunctive probiotics compared to placebo, using conventional and novel treatment outcomes. MATERIALS AND METHODS: Three databases (MEDLINE, EMBASE, and CENTRAL) were searched. Outcomes included percent change in the total number of deep sites before and after therapy, change in mean probing pocket depth (mm), percentage patients requiring additional therapy, risk for disease progression, and microbiological and immunological results. Meta-analysis was conducted to evaluate treatment effects wherever appropriate. RESULTS: Ten studies were selected from 818 records. Meta-analysis showed that adjunctive probiotics had no additional benefit for percentage change of the total number of deeper sites (≥5 mm, ≥6 mm, ≥7 mm) before and after therapy. No significant difference was observed for mean probing pocket depth reduction at 3 and 6 months. Statistically significant beneficial odds ratios for need for additional therapy (OR = 0.19, 95% CI [0.07-0.56]) and risk of disease progression (OR = 0.32, 95% CI [0.14-0.73]) were observed with probiotic administration. Immunological rather than microbiological outcomes correlated more consistently with clinical findings. No adverse events were reported. CONCLUSIONS: Adjunctive probiotics are safe in systemically healthy individuals and could offer additional patient-level benefits compared to placebo, hence its use can sometimes be justified.

Metagenomic sequencing provides new insights into the subgingival bacteriome and aetiopathology of periodontitis.

"Open-ended" molecular techniques such as 16S rRNA sequencing have revealed that the oral bacteriome of subgingival plaque is more diverse than originally thought. 16S rRNA analysis has demonstrated that constituents of the overall bacterial community are qualitatively similar in health and disease, differing mainly in their relative proportions with respect to each other. Species in low abundance can also act as critical species, leading to the concept of global community dysbiosis which relates to shifts in community structure, rather than shifts in membership. Correlation analysis suggests that coordinated interactions in the community are essential for incipient dysbiosis and disease pathogenesis. The subgingival bacteriome also provides biomarkers that are useful for disease detection and management. Combined with clinical and biological parameters, these may assist clinicians in developing and implementing effective treatment strategies to restore microbial homeostasis and monitor disease. Identification of higher risk groups or poor responders to treatment using unique subgingival bacteriome signatures may also lead to early intervention.

Influence of periodontal maintenance and periodontitis susceptibility on implant success: A 5-year retrospective cohort on moderately rough surfaced implants.

OBJECTIVES: To investigate the effect of defined versus undefined periodontal maintenance after implant therapy on the prevalence of peri-implant complications. MATERIAL AND METHODS: Two hundred patients who underwent dental implant therapy in the National Dental Centre Singapore (NDCS) from 2005 to 2012 were recruited. One hundred patients had regular periodontal maintenance (defined maintenance programme group, DMP), and the other 100 patients had no documentation of periodontal maintenance (undefined maintenance programme group, UMP). Full-mouth bleeding scores (FMBS), periodontal probing depths (PPD) and peri-implant probing depths (PiPD) were evaluated within 6 months of prostheses delivery (T0 ) and at re-examination (T1 ). Peri-implant bone level changes were analysed radiographically. RESULTS: The mean follow-up time was 6.8 years. Five out of 289 implants were lost (cumulative survival rate = 98.3%). 6.0% of DMP patients and 20.0% of UMP patients had peri-implantitis (p = .003). Peri-implantitis was defined as bleeding on probing, increase in PiPD and peri-implant bone loss ≥ 0.5 mm. At the implant level, 4.0% of the DMP group implants and 17.2% of the UMP group implants were diagnosed with peri-implantitis (p = .0003). One implant in the DMP group and 13 implants in the UMP group had bone loss ≥ 2 mm (p < .0001). Multivariate regression showed that absence of regular maintenance (OR = 0.24, p = .003) was significantly associated with peri-implantitis. CONCLUSIONS: Regular periodontal maintenance was associated with a lower prevalence of peri-implantitis and peri-implant bone loss. Patients with treated periodontitis without regular maintenance after implant placement were at higher risk for developing peri-implantitis.

Influence of maintenance care in periodontally susceptible and non-susceptible subjects following implant therapy.

OBJECTIVES: To compare the periodontal and peri-implant conditions of periodontally susceptible and periodontally healthy subjects under maintenance care for a period of at least 3 years. MATERIAL AND METHODS: Sixty periodontally susceptible patients (PSP) and 56 periodontally non-susceptible subjects (PHS) were treated with dental implants in the National Dental Centre Singapore (NDCS) and were maintained in a regular supportive periodontal care program for a mean of 6 years. Full mouth bleeding on probing (BoP), full mouth probing pocket depths (PPD), implant loss, and absence of crestal bone loss were recorded at the time of prosthesis delivery and following a mean follow-up of 6 years 2 months. RESULTS: Although there were significant differences in the BoP and the percentage of subjects with tooth probing pocket depth ≥5 mm between PSP and PHS at the time of implant prosthesis installation (T0 ), there were no significant differences between the two subject groups in the various parameters assessed at the follow-up visit (T1 ) (total number of teeth, percentage of subjects with implant probing pocket depth ≥5 mm, percentage of subjects with implant probing pocket depth ≥ 6 mm, absence of crestal bone loss, implant loss). CONCLUSION: Owing to a rigid regular SPT program, implants placed in PSP perform equally well when compared to implants installed in PHS over a mean period of 6-year follow-up.

Patient-reported outcome measures after routine periodontal and implant surgical procedures.

OBJECTIVES: To compare patient-reported outcome measures (PROMs) after different dental surgical procedures over a 1-week post-surgical period and in relation to duration of the surgery, and periosteal releasing incisions. To evaluate the prevalence of post-surgical complications. MATERIAL & METHODS: Four hundred and sixty-eight healthy dental patients requiring surgeries, such as crown lengthening (CL), open flap debridement (OFD) and implant installation (IMP) in the National Dental Centre, Singapore (2009-2011), were consecutively recruited. PROMs on bleeding, swelling, pain and bruising were obtained using Visual Analogue Scales (VAS) on days 0, 3, 5 and 7 post-operatively. RESULTS: On the day of surgery, the IMP procedure gave the lowest median VAS for all four PROM parameters. After a week, OFD still had a significantly higher VAS for swelling, pain and bruising. Patients who underwent procedures lasting more than 60 min. had higher VAS for all parameters except bleeding. After considering other important confounders, type of surgery procedure was no longer associated with the VAS score for any of the parameters. Time after surgery, male gender and shorter surgery duration reduced post-operative VAS for one or more of the parameters. Longer surgeon experience helps reduce VAS scores only for bleeding. Prevalence for tenderness to palpation was 11.6%, 8.9% and 12.2% for IMP, CL and OFD, respectively, 1-week post-operatively. Swelling and suppuration occurred rarely. CONCLUSIONS: The median VAS scores for all PROM parameters were generally low and reduced to near zero over a week following all three surgical procedures tested. Time after surgery and shorter surgery duration were associated with lower VAS scores in all the PROM parameters in this cohort of patients. Surgery type was not associated significantly with VAS after adjustment with other important confounders. Low prevalences of post-surgical complications were reported.

Effect of systemic antibiotics on clinical and patient-reported outcomes of implant therapy - a multicenter randomized controlled clinical trial.

OBJECTIVES: To determine the effect of various systemic antibiotic prophylaxis regimes on patient-reported outcomes and postsurgical complications in patients undergoing conventional implant installation. MATERIAL AND METHODS: Three hundred and twenty-nine healthy adults in need of conventional implant installation were randomly assigned to one of four groups: (i) preoperatively 2 g of amoxycillin 1 h before surgery (positive control, PC), (ii) postoperatively 2 g of amoxycillin immediately following surgery (test 1, T1), (iii) preoperatively 2 g of amoxycillin 1 h before and 500 mg thrice daily on days 2 and 3 after surgery (test 2, T2), (iv) preoperatively 2 g of placebo 1 h before surgery (negative control, NC). Subjects were examined clinically by blinded examiners over 8 weeks after implant installation. In addition, Visual Analogue Scales (VAS) for pain, swelling, bruising and bleeding were obtained over 14 days. ANOVA was performed for the VAS. Chi-square tests were applied for postsurgical complications. RESULTS: All VAS scores were low for all groups and decreased over time (P < 0.001). There were no significant differences for the VAS scores between the various groups at any time point (P > 0.05). There was only a significant difference in flap closure at week 4, where NC had 5% of the subjects not achieving complete wound closure compared to 0% for the three other groups (P = 0.01), with no other significant differences for any postsurgical complications (P > 0.05). CONCLUSION: For standard single implant placement, prophylactic systemic antibiotics either before or after, or before and after the surgical procedure do not improve patient-reported outcomes or prevalence of postsurgical complications.

Tooth loss in compliant and non-compliant periodontally treated patients: 7 years after active periodontal therapy.

AIMS: To investigate the incidence and reasons for tooth loss during active periodontal therapy (APT) and periodontal maintenance (PM) in a specialist institution. MATERIAL AND METHODS: Retrospective data were collected from 273 patients [all compliers (AC)] and cross-sectional data from 39 patients after discontinuation of PM [non-compliers (NC)] for at least 7 years after APT. Descriptive statistics and regression analysis were performed. A comparison was made between AC and NC. The prognostic factors associated with tooth loss during PM were identified. RESULTS: AC lost 1.3 teeth/patient during APT and 0.9 teeth/patient during PM (mean 10.7 years). Tooth loss due to periodontitis was 0.03 teeth/patient/year. The age of 60 was a significant predictor of tooth loss during PM (odds ratio of 2.1). NC lost 1.1 teeth/patient during APT and 2.7 teeth/patient during discontinuation (mean 9.6 years). Tooth loss due to periodontitis was 0.22 teeth/patient/year, a sevenfold increase (p<0.05) compared with AC. Regression analysis failed to identify any significant predictors for tooth loss during the discontinuation of PM. CONCLUSIONS: In this study, the provision of PM led to minimal tooth loss, especially due to periodontitis, for a mean period of 10 years after APT. The completion of APT without PM may predispose patients to lose more teeth compared with patients who undergo PM.

Minimally Invasive Periodontology: A Treatment Philosophy and Suggested Approach.

Severe periodontitis is a highly prevalent dental disease. With the advent of implant dentistry, teeth are often extracted and replaced. Periodontal surgery, where indicated, could also result in increased trauma to the patient. This literature review discusses different treatment modalities for periodontitis and proposes a treatment approach emphasizing maximum preservation of teeth while minimizing morbidity to the patient. Scientific articles were retrieved from the MEDLINE/PubMed database up to January 2021 to identify appropriate articles that addressed the objectives of this review. This was supplemented with hand searching using reference lists from relevant articles. As tooth prognostication does not have a high predictive value, a more conservative approach in extracting teeth should be abided by. This may involve repeated rounds of nonsurgical periodontal therapy, and adjuncts such as locally delivered statin gels and subantimicrobial-dose doxycycline appear to be effective. Periodontal surgery should not be carried out at an early phase in therapy as improvements in nonsurgical therapy may be observed up to 12 months from initial treatment. Periodontal surgery, where indicated, should also be minimally invasive, with periodontal regeneration being shown to be effective over 20 years of follow-up. Biomarkers provide an opportunity for early detection of disease activity and personalised treatment. Quality of life is proposed as an alternative end point to the traditional biomedical paradigm focused on the disease state and clinical outcomes. In summary, minimally invasive therapy aims to preserve health and function of the natural dentition, thus improving the quality of life for patients with periodontitis.

A Risk-Based Approach to the COVID-19 Pandemic: The Experience in National Dental Centre Singapore.

The emergence of a highly infectious coronavirus strain, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a major global public health emergency. The increasing number of infected cases and fatalities worldwide forced several countries into lockdown in a bid to control virus transmission. The practice of dentistry is considered high-risk due to the generation of aerosols associated with most dental procedures, and healthcare professionals must take appropriate precautions whilst working in this challenging environment. This review aims to provide an overview on transmission routes and shares a risk-based approach to coronavirus disease 2019 (COVID-19) in a specialty tertiary center. Risk assessment and mitigation focussed on staff and patient safety, adopting a wide safety margin, and responding dynamically to the level of risk at the workplace. As the severity of the pandemic depends on many still-unknown factors and shows little sign of abating, the routine practice of dentistry will continue to be disrupted in the near future. We describe a color-coded framework to maximize safety and to minimize disease spread. Areas covered include healthcare team management, personal protective equipment, clinical work, and dental education. Guidelines in each category change with the corresponding severity of the situation, and we believe it will be useful for the safer practice of dentistry in this current climate and can be modified for future similar disease outbreaks.

Pterostilbene complexed with cyclodextrin exerts antimicrobial and anti-inflammatory effects.

Resveratrol (RES) is a natural polyphenol with potential as an adjunctive therapeutic modality for periodontitis. However, its inferior pharmacokinetics and toxicity concerns about its commonly used solvent dimethyl sulfoxide (DMSO) hinder translation to clinical applicability. Our study aimed to investigate the comparative antimicrobial properties of RES and its analogues (pterostilbene [PTS], oxyresveratrol [OXY] and piceatannol [PIC]), utilizing 2-hydroxypropyl-ß-cyclodextrin (HPßCD) as a solubiliser, which has a well-documented safety profile and FDA approval. These properties were investigated against Fusobacterium nucleatum, a key periodontal pathogen. PTS demonstrated the most potent antibacterial effects in HPßCD, with MIC > 60-fold lower than that of RES, OXY and PIC. In addition, PTS inhibited F. nucleatum biofilm formation. PTS exerted antimicrobial effects by eliciting leakage of cellular contents, leading to loss of bacterial cell viability. PTS also conferred immunomodulatory effects on F. nucleatum-challenged macrophages via upregulation of antioxidant pathways and inhibition of NF-κB activation. Given the superior antimicrobial potency of PTS against F. nucleatum compared to RES and other analogues, and coupled with its immunomodulatory properties, PTS complexed with HPßCD holds promise as a candidate nutraceutical for the adjunctive treatment of periodontitis.

Anatomical, microbiological, and genetic considerations in treatment of Chinese periodontal patients.

The aim of the present narrative review was to highlight considerations when treating Chinese patients with periodontal diseases. These considerations can be broadly categorized into anatomical, microbiological, and genetic considerations. Anatomical considerations are tooth-related factors causing site-specific issues, and these include incisal palatal groove, root concavities, three-rooted permanent mandibular first molar, furcation entrance dimensions, cervical enamel projections, root trunk length, and molar root fusion. Aggregatibacter actinomycetemcomitans was found to be commensal in the oral flora of Chinese. The association between a single gene polymorphism and periodontal disease has not been unequivocally proven in Chinese populations. Despite these subtle differences compared to other ethnic populations, studies of Chinese participants from various geographic regions have demonstrated that periodontal disease in this particular ethnic group can be successfully treated.

Application of BMP-Bone Cement and FGF-Gel on Periodontal Tissue Regeneration in Nonhuman Primates.

The ultimate challenge of tissue engineering research is the translation of experimental knowledge into clinical application. In the preclinical testing phase of any new therapy, animal models remain the gold standard. Therefore, the methodological choice of a suitable model is critical to meet the requirements for a safe clinical application of the developed treatment. For instance, we have shown in rats that the application of calcium phosphate cement (CPC)/propylene glycol alginate (PGA) with bone morphogenetic protein (BMP)-2 or fibroblast growth factor (FGF)-2 resulted in the regeneration of periodontal defects. However, it is debated whether using small models form a predictive method for translation to larger species. At the same time, the 3R framework is encouraged as guiding principles of the ethical use of animal testing. Therefore, based on the successful rat study, the objective of this study was to further investigate the periodontal regenerative efficacy of the CPC/BMP and PGA/FGF system in a periodontal defect model with a low number of nonhuman primates (NHPs). Three Macaca fascicularis-overstocked from breeding for other purposes-were used (reuse of animals and appropriateness of the experimental animal species according to 3R framework). Three-wall periodontal defects were surgically created in the mandible. In total, 10 defects were created and distributed over two groups: (1) control group: PGA+CPC (n = 5) and (2) experimental group: PGA/FGF+CPC/BMP (n = 5). After 3 months, tissue regeneration was evaluated by histomorphometry and radiographic measurements. Data showed that epithelial downgrowth, cementum, and ligament regeneration were significantly enhanced in the experimental group compared with the control group (n = 5; p = 0.013, p = 0.028, and p = 0.018, respectively). However, the amount of newly formed bone did not differ (p = 0.146). Overall, as a translational proof-of-principle study, the hybrid periodontal regenerative method of CPC/BMP+PGA/FGF promoted periodontal regeneration in NHPs. This study warrants the application of CPC/BMP/PGA/FGF in clinical trials. Impact Statement This study validated an earlier successful periodontal regeneration strategy from a rat model into a few spare nonhuman primates (NHPs). The hybrid periodontal regenerative method of calcium phosphate cement (CPC)/bone morphogenetic protein (BMP)-2/propylene glycol alginate (PGA)/fibroblast growth factor (FGF)-2 promoted periodontal regeneration in NHPs, which corroborated the previous rat results. This translational approach was a very practical option and thus reduced the number and species of experimental animals in translational research. These results found in NHPs indicate a consistent conclusion with the earlier findings in the rat model. It further warrants the application of CPC/BMP-2+PGA/FGF-2 in human clinical trials.

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.

Use of a collagen matrix for recession coverage in patients who received orthodontic therapy: a case series.

AIM: The aim of the present study was to determine the percentage of recession coverage achieved following surgery with a collagen matrix, and patient-reported outcome measures. METHODS: Five healthy adults who had completed orthodontic therapy with a gingival recession defect were recruited. Gingival recession coverage was performed using a two-layer, xenogeneic collagen matrix (Mucograft). During the first 2 weeks, the patients charted their perceptions on bleeding, swelling, pain, and bruising using a visual analog scale (VAS). Post-surgical complications were assessed clinically at 1 week, 2 weeks, and 1 month post-surgery. Recession dimensions were examined at 1, 3, 6, and 12 months. RESULTS: At 1 year, an average of 67% root coverage was achieved. The amount of recession coverage achieved was stable from 3 months. The results were maintained at 1 year. There were no post-surgical complications. All VAS parameters decreased to almost zero by day 14. From day 1, bleeding and pain decreased over time. However, there were peaks on days 2 and 3 for swelling and bruising, respectively, followed by a subsequent decrease. CONCLUSIONS: The use of Mucograft for recession coverage is effective and safe, with low morbidity and no post-surgical complications. Recession coverage achieved at 3 months remained stable in the 1-year follow-up period.

Effects of enamel matrix derivative and transforming growth factor-ß1 on connective tissue growth factor in human periodontal ligament fibroblasts.

BACKGROUND: Enamel matrix derivative (EMD) is suggested to stimulate transforming growth factor-ß (TGF-ß) production. Connective tissue growth factor (CTGF) is a downstream mediator of TGF-ß. This study explores the effects of EMD and TGF-ß1 on CTGF in periodontal ligament (PDL) fibroblasts and their interactions in PDL proliferation and development. METHODS: Human PDL cells were stimulated with EMD. To explore the effects of EMD and TGF-ß1 on CTGF expression, cells were treated with and without TGF-ß inhibitor, and CTGF protein levels were assayed by Western blot analysis. To study the role of CTGF in PDL development, cells were treated with CTGF inhibitor. DNA synthesis was analyzed by bromodeoxyuridine enzyme-linked immunosorbent assay. Reverse-transcription polymerase chain reaction was performed to examine messenger RNA expression of PDL osteoblastic differentiation markers: type I collagen, alkaline phosphatase, and osteocalcin. RESULTS: EMD induced a concentration-dependent increase of CTGF protein expression in PDL cells. EMD- and TGF-ß1-stimulated CTGF expression was significantly reduced in the presence of TGF-ß inhibitor. CTGF inhibition downregulated both EMD- and TGF-ß1-induced DNA synthesis. The effect of CTGF and EMD on osteoblastic mRNA expression in PDL cells is not obvious. CONCLUSIONS: EMD stimulates CTGF expression in human PDL cells, a process modulated by the TGF-ß pathway. CTGF can affect EMD- and TGF-ß1-induced PDL cell proliferation, but its effects on PDL with regard to osteoblastic differentiation remain inconclusive. The results provide novel insights into EMD-CTGF interaction in PDL cells.

Use of the apically repositioned flap in the management of labially impacted maxillary central incisors.

Management of labially impacted maxillary central incisors often requires a coordinated surgical and orthodontic approach. In such cases, the treatment objective is surgical exposure of the unerupted incisor, preferably with a functional width of keratinized gingiva on the labial surface. Tooth exposure is then followed by orthodontic intervention to move the tooth to the line of occlusion. This paper describes three cases where the apically repositioned flap technique was used to manage labially impacted maxillary central incisors.

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.