Enamel Matrix Derivative in Propylene Glycol Alginate for Treatment of Infrabony Defects With or Without Systemic Doxycycline: 12- and 24-Month Results

Comparison of immediate vs. delayed guided tissue regeneration in Infrabony defect of second molars after adjacent third molar extraction: a retrospective study

BACKGROUND

The distal aspect of the second molar (d-M2) often exhibits infrabony defects due to the adjacent third molar. Although the defects can be treated by guided tissue regeneration (GTR) after removing the third molar, the optimal timing remains uncertain following third molar removal in clinical decision-making. This study aimed to compare delayed and immediate GTR treatments to assist in clinical decision-making.

METHODS

D-M2 infrabony defects with a minimum 1-year follow-up were collected and divided into three groups: Immediate GTR group, which underwent third molar extraction and received GTR simultaneously; Delayed GTR group, which underwent delayed GTR at least 3 months after third molar extraction; and Control group, which underwent only scaling and root planing during third molar extraction. The clinical and radiographic parameters related to the infrabony defect before GTR and post-surgery were evaluated using the Kruskal-Wallis test or one-way ANOVA, followed by post-hoc Dunn's test or the Bonferroni test for pairwise comparisons.

RESULTS

A total of 109 d-M2 infrabony defects were assessed. No significant differences were found between the two GTR groups, although both of them showed significant reductions in infrabony defect depth: the immediate GTR group (2.77 ± 1.97 mm vs. 0.68 ± 1.03 mm, p < 0.001) and the delayed GTR group (2.98 ± 1.08 mm vs. 0.68 ± 1.03 mm, p < 0.001) compared to the control group.

CONCLUSION

GTR can effectively improve d-M2 infrabony defects when the third molar is removed, whether simultaneously or delayed. Patients may experience less discomfort with immediate GTR treatment as it requires only one surgery.

Long-term stability of infrabony defects treated with enamel matrix derivative alone: A retrospective two-centre cohort study

AIM

To assess the long-term stability of attachment gain in infrabony defects (IBDs) 10 years after regenerative treatment with an enamel matrix derivative (EMD) alone.

MATERIALS AND METHODS

Two centres (Frankfurt [F] and Heidelberg [HD]) invited patients for re-examination 120 ± 12 months after regenerative therapy. Re-examination included clinical examination (periodontal probing depths (PPD), vertical clinical attachment level (CAL), plaque index (PlI), gingival index (GI), plaque control record, gingival bleeding index and periodontal risk assessment) and review of patient charts (number of supportive periodontal care [SPC] visits).

RESULTS

Both centres included 52 patients (29 female; median baseline age: 52.0 years; lower/upper quartile: 45.0/58.8 years; eight smokers), each contributing one IBD. Nine teeth were lost. For the remaining 43 teeth, regenerative therapy showed significant CAL gain after 1 year (3.0; 2.0/4.4 mm; p < .001) and 10 years (3.0; 1.5/4.1 mm; p < .001) during which CAL remained stable (-0.5; -1.0/1.0 mm; p = 1.000) after an average SPC of 9 years. Mixed-model regression analyses revealed a positive association of CAL gain from 1 to 10 years with CAL 12 months post operation (logistic: p = .01) as well as a higher probability for CAL loss with an increasing vertical extent of a three-walled defect component (linear: p = .008). Cox proportional hazard analysis showed a positive association between PlI after 12 months and tooth loss (p = .046).

CONCLUSION

Regenerative therapy of IBDs showed stable results over 9 years. CAL gain is associated with CAL after 12 months and decreasing initial defect depth in a three-walled defect morphology. Tooth loss is associated with PlI 12 months post operation.

CLINICAL TRIAL NUMBER

DRKS00021148 (URL: https://drks.de).

Ten-Year Stability of Clinical Attachment after Regenerative Treatment of Infrabony Defects and Controls

Background: A similar long-term stable clinical attachment level (CAL) of infrabony defects (IBDs) after regenerative treatment compared to control teeth would indicate a high level of stability resulting from the regenerative approach. Methods: Patients with a regeneratively treated IBD were screened 120 ± 12 months postoperatively for eligibility for study participation, and were included if complete baseline and 12-month examinations (plaque (PlI), periodontal probing depth (PPD), CAL) were available and a respective control tooth could be identified. Re-examination included clinical examination (PPD, CAL, PlI/GI, bleeding on probing, plaque control record, gingival bleeding index). Results: A total of 27 patients (16 females; age (median; lower/upper quartile): 57.0; 44.0/60.0 years; 6 smokers) contributed 27 IBDs (test), for each of which a control tooth was identified. Five test teeth (18.5%) were lost between 12 and 120 months. The remaining 22 test teeth revealed a significant CAL gain after 1 (2.5 mm; 1.0/4.0 mm, p < 0.0001) and 10 (2.5 mm; 0.5/3.5 mm, p < 0.0001) years, whereas control teeth were stable (1 year: 0.0 mm; 0.0/1.0 mm, p = 0.396; 10 years: 0.0 mm; −1.0/1.5 mm, p = 0.215). The study did not detect any significant CAL change between 1 and 10 years for test (−0.5 mm; −1.0/0.5 mm, p = 0.414) and control teeth (0.0 mm; −1.0/1.0 mm, p = 0.739). In 15 patients, test and control teeth revealed stable CAL values between 12 and 120 months. Conclusion: Regenerative treatment of IBDs exhibited stability comparable to non-surgically treated, periodontally reduced sites over a 10-year period.

Adjunctive Effect of Systemic Antibiotics in Regenerative/Reconstructive Periodontal Surgery-A Systematic Review with Meta-Analysis

Background and Objective: Systemic antibiotics (AB) are often used in conjunction with regenerative/reconstructive periodontal surgery of intrabony defects and furcations; however, their potential benefits have not been systematically assessed. Materials and Methods: Data were retrieved from two recent systematic reviews (a total of 105 randomized clinical trials (RCTs) on clinical and radiographic outcomes in intrabony defects (ID) and molars with furcation involvement (FI) treated by surgical access with regenerative techniques. Pair-wise meta-analysis of RCTs with and without AB was performed. Meta-regressions from single-arm (subgroup) RCTs including study arms with or without adjunctive AB were also conducted. Results: No statistically significant benefits of systemic AB with regard to PPD, CAL and bone gain were detected in ID by pair-wise meta-analysis. Meta-regression revealed increased PPD reduction (−0.91 mm, 95% CI = −1.30; −0.51, p < 0.001), CAL gain (−0.92 mm, 95% CI = −1.32; −0.52, p < 0.001) and bone gain (−1.08 mm, 95% CI = −1.63; −0.53, p < 0.001) in ID but not in any of the outcomes in FI for arms treated with AB vs. study arms treated with no AB. No clear differences in adverse events were detected between AB and non-AB groups. Conclusion: There is only weak indirect evidence that AB may provide additional benefits in terms of clinical improvements in the regenerative/reconstructive periodontal surgery of intrabony defects and no evidence for a benefit in furcations. Until new data are gained and in the context of antibiotic stewardship, it may be questionable to justify the adjunctive use of systemic antibiotics.

Effect of locally delivered adjunctive antibiotics during surgical periodontal therapy: a systematic review and meta-analysis

Aim

The present study aimed to systematically assess current evidence on effects of locally delivered antibiotics during periodontal surgery compared to periodontal surgery alone on clinical attachment level (CAL) gain, probing pocket depth (PPD) reduction, recession depth (RD) changes, gingival index (GI), bleeding on probing (BOP), and plaque index (PI).

Methodology

MEDLINE-PubMed, Cochrane-CENTRAL and Scopus databases were searched up to April 2021 for randomized clinical trials (RCT), evaluating effects of locally delivered antibiotics during periodontal surgery. CAL gain served as primary, while PPD reduction, RD changes, GI and PI as secondary outcomes. The Cochrane Risk of Bias Tool was used to assess possible bias. Data were extracted, and meta-analysis was performed where appropriate.

Result

Screening of 2314 papers resulted in nine eligible studies. No adverse events were reported. Data on outcome variables were pooled and analyzed using generic inverse variance model and presented as weighted mean difference (WMD) and 95% confidence interval (95% CI). Statistically significant improvements in favor of antibiotics’ delivery were observed in studies with follow-up of ≤6 months for CAL gain (WMD = 0.61 mm (95% CI [0.07, 1.14]; p = 0.03), PPD reduction (WMD = 0.41 mm (95% CI [0.02, 0.80]; p = 0.04)) and BOP (WMD = −28.47% (95% CI [−33.00, −23.94]); p < 0.001), while for GI improvements were notable for >6 to 12 months (WMD = −0.27 (95% CI [−0.49, −0.06]; p = 0.01)).

Conclusion

Within the current review’s limitations, locally delivered antibiotics during surgical periodontal therapy results in post-surgical improvements for CAL, PPD, and BOP (≤6 months) with a longer-lasting GI improvement. Further randomized controlled trials are needed with true periodontal end-points to assess the ideal antibiotic agent, dosage, and delivery methods.

Clinical relevance

Local delivery of antibiotics during periodontal surgery improved clinical parameters for up to 6-month follow-up, with beneficial longer effects on gingival inflammation. Within the current study’s limitation, the presented evidence could support the elective usage of locally delivered antibiotics during surgical periodontal therapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04056-7.

Periodontal infrabony defects: Systematic review of healing by defect morphology following regenerative surgery

BACKGROUND

It is thought that infrabony defect morphology affects the outcome of periodontal regenerative surgery. However, this has not been systematically investigated.

AIMS

To investigate how well defect morphology is described in papers reporting regenerative therapy of periodontal infrabony defects and to investigate its effect on clinical and radiographic outcomes.

MATERIALS AND METHODS

A search was conducted in 3 electronic databases for publications reporting clinical and radiographic outcomes of periodontal intra-bony defects after regenerative therapy, divided by defect morphology.

RESULTS

The initial search resulted in 4487 papers, reduced to 143 after first and second screening. Fifteen of these publications were suitable for a fixed-effects meta-analysis. Initial defect depth was found to influence radiographic bone gain 12 months post-surgery, while narrower angles and increased number of walls influenced both radiographic bone gain and clinical attachment level (CAL) gain at 12 months. These associations seemed to occur irrespective of biomaterials used. Risk of bias ranged from low to high.

CONCLUSION

Deeper defects with narrower angles and increased number of walls exhibit improved CAL and radiographic bone gain at 12 months post-regenerative surgery. More data are needed about other aspects of defect morphology such as extension to buccal/lingual surfaces.

Effect of systemic antibiotics on the outcomes of regenerative periodontal surgery in intrabony defects: a randomized, controlled, clinical study

OBJECTIVES

To assess the potential influence of systemic antibiotic administration on the healing of periodontal intrabony defects treated with deproteinized bovine bone mineral (DBBM) and collagen membrane.

MATERIALS AND METHODS

Forty-one intrabony defects were treated by means of DBBM and collagen membrane (GTR). Postoperatively, the patients received either systemic antibiotics (i.e., 1 g of amoxicillin, twice daily for 7 days) (test) or no antibiotics (control). Clinical attachment level (CAL), probing depth (PD), and gingival recession (GR) were measured at baseline and at 1 year following regenerative surgery. The depth of the intrabony component (INTRA DD) and its width (INTRA DW) were measured during surgery and after 1 year at reentry. The depth (RxD) and width (RxW) of the intrabony defects were evaluated radiographically at baseline and at 1 year.

RESULTS

No adverse events were observed in any of the two groups throughout the entire study period. In the test group, mean CAL changed from 8.7 ± 1.4 mm at baseline to 5.0 ± 1.7 mm at 1 year (p < 0.0001), while PD decreased from 7.8 ± 1.5 mm at baseline to 4.0 ± 0.9 mm at 1 year (p < 0.0001). In the control group, mean CAL changed from 8.6 ± 1.9 mm to 5.9 ± 1.6 mm (p < 0.001) and mean PD improved from 7.4 ± 1.3 mm to 4.1 ± 1.3 mm (p < 0.001). Mean CAL gain measured 3.6 ± 1.6 mm in the test and 2.7 ± 1.6 mm in the control group, respectively. Defect fill (i.e., INTRA DD gain) at re-entry measured 3.7 ± 1.8 mm in the test and 2.7 ± 2.1 mm in the control group. A CAL gain of ≥ 3 mm was measured in 76% of the defects in the test group and in 40% of the defects in the control group, respectively. In both groups, all evaluated clinical and radiographic parameters improved statistically significantly compared with baseline, but no statistically significant differences were found between the two groups.

CONCLUSIONS

Within their limits, the present study has failed to show any substantial added clinical benefits following the postoperative administration of amoxicillin in conjunction with regenerative periodontal surgery using DBBM and GTR.

CLINICAL RELEVANCE

The post-surgically administration of systemic antibiotics does not seem to be necessary following regenerative periodontal surgery.

Antimicrobial effect of nanostructured membranes for guided tissue regeneration: an in vitro study

OBJECTIVE

The purpose of this in vitro study was to evaluate the antibacterial effect of a novel non-resorbable, bioactive polymeric nanostructured membrane (NMs), when doped with zinc, calcium and doxycycline.

METHODS

A validated in vitro subgingival biofilm model with six bacterial species (Streptococcus oralis, Actinomyces naeslundii, Veillonela parvula, Fusobacterium nucleatum, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans) was used. The experimental NMs, with and without being doped with doxycycline, calcium and zinc, were placed on hydroxyapatite (HA) discs. As positive control membranes, commercially available dense polytetrafluoroethylene (d-PTFE) membranes were used and, as negative controls, the HA discs without any membrane. The experimental, positive and negative control discs were exposed to a mixed bacterial suspension, at 37 °C under anaerobic conditions, during 12, 24, 48 and 72 h. The resulting biofilms were analyzed through scanning electron microscopy (SEM), to study their structure, and by quantitative polymerase chain reaction (qPCR), to assess the bacterial load, expressed as colony forming units (CFU) per mL. Differences between experimental and control groups were evaluated with the general linear model and the Bonferroni adjustment.

RESULTS

As shown by SEM, all membrane groups, except the NMs with doxycycline, resulted in structured biofilms from 12-72 hours. Similarly, only the membranes loaded with doxycycline demonstrated a significant reduction in bacterial load during biofilm development, when compared with the control groups (p < 0.001).

SIGNIFICANCE

Doxycycline-doped nanostructured membranes have an impact on biofilm growth dynamics by significant reducing the bacterial load.

Core-Shell poly-(D,l-Lactide-co-Glycolide)-chitosan Nanospheres with simvastatin-doxycycline for periodontal and osseous repair

This study aimed to evaluated the potential of core-shell poly(D,l-lactide-co-glycolide)-chitosan (PLGA-chitosan) nanospheres encapsulating simvastatin (SIM) and doxycycline (DOX) for promoting periodontal and large-sized osseous defects. SIM, and/or DOX were encapsulated in PLGA-chitosan nanospheres using double emulsion technique and were delivered to sites of experimental periodontitis and large-sized mandibular osseous defects of rats for 1-4 weeks. The resultant nanospheres were ~ 200 nm diameter with distinct core-shell structure and released SIM and DOX sustainably for 28 days. DOX and SIM-DOX nanospheres significantly inhibited P. gingivalis and S. sanguinis. In experimental periodontitis sites, SIM-DOX nanospheres significantly down-regulated IL-1b and MMP-8 and significantly reduced bone loss. In mandibular osseous defects, VEGF was up-regulated, and osteogenesis was significantly augmented with SIM nanospheres treatment. In conclusion, core-shell PLGA-chitosan nanospheres released SIM and DOX sustainably. SIM-DOX and SIM nanospheres could be considered to promote the repair of infected periodontal sites and non-infected osseous defects respectively.

Prophylactic antibiotics for staged bone augmentation in implant dentistry

Background: The objective of the study was to assess the effect of prophylactic antibiotics on the outcome of bone augmentation and subsequent dental implant placement by combining the recommended quality assessment methods for systematic reviews and primary studies.Materials and methods: This is a complex systematic review in which systematic reviews as well as primary studies are scrutinised. A search of Medline (OVID), The Cochrane Library (Wiley) and EMBASE, PubMed and Health technology assessment (HTA) organisations as-well as a complementary hand-search was carried out. Selected primary studies were assessed using GRADE. Each study was reviewed by three authors independently.Results: Abstract screening yielded six potential systematic reviews allocated for full-text inspection. A total of ten primary studies were read in full-text. No relevant systematic reviews regarding the topic of this article were found. The quality assessment resulted in two primary studies with a moderate risk of bias. Of the two studies with a moderate risk of bias, one compared a single dose of clindamycin 600 mg preoperatively with the same preoperative dose followed by four doses of 300 mg every 6 h. The second study compared a single dose prophylaxis of two different types of antibiotic compounds.Conclusion: In conclusion, the scientific evidence regarding the use of antibiotic prophylaxis for reducing the risk of infection in conjunction with bone augmentation procedures during dental implant placement is very limited. The infection rate as compared to nonusage of prophylactic antibiotics, selection of the most suitable compound, and the optimal duration of prophylactic treatment is still unknown.

Five-year stability of clinical attachment after regenerative treatment of infrabony defects compared to controls

AIM

To evaluate the stability of attachment achieved in infrabony defects by regenerative treatment over 60 ± 12 months compared to control teeth.

METHODS

Patients treated regeneratively in at least one infrabony defect between 2004 and 2010 were screened for this retrospective cohort study. Complete examinations available for baseline, 12 and 60 ± 12 months after surgery, and a respective control tooth without treatment, provided eligibility for analysis.

RESULTS

Twenty-seven patients (age 58 ± 11.7 years; 12 females, five smokers) were included, each contributing one infrabony defect and one control tooth. Regenerative therapy resulted in significant attachment gain (2.7 ± 1.6 mm; p < 0.001) after 1 and (3.0 ± 2.2 mm; p < 0.001) 5 years. Control teeth were stable (vertical probing attachment level [PAL-V] change: 1 year: 0 ± 0.8 mm; 5 years: -0.2 ± 1.2 mm). The study did not detect any significant change of PAL-V from 1 to 5 years after surgery for regenerative (-0.3 ± 2.4 mm) and control teeth (-0.2 ± 1.4 mm). Multivariate analysis associated smoking and generalized recurrence of periodontitis (amount of sites with PPD > 5 mm) with attachment loss.

CONCLUSIONS

PAL-V achieved by regenerative therapy in infrabony defects is as stable over 5 years as periodontally reduced but gingivally healthy or gingivitis sites. Smoking and periodontitis recurrence are associated with attachment loss.

Twenty years of enamel matrix derivative: the past, the present and the future

BACGROUND

On June 5th, 2015 at Europerio 8, a group of leading experts were gathered to discuss what has now been 20 years of documented evidence supporting the clinical use of enamel matrix derivative (EMD). Original experiments led by Lars Hammarström demonstrated that enamel matrix proteins could serve as key regenerative proteins capable of promoting periodontal regeneration including new cementum, with functionally oriented inserting new periodontal ligament fibres, and new alveolar bone formation. This pioneering work and vision by Lars Hammarström has paved the way to an enormous amount of publications related to its biological basis and clinical use. Twenty years later, it is clear that all these studies have greatly contributed to our understanding of how biologics can act as mediators for periodontal regeneration and have provided additional clinical means to support tissue regeneration of the periodontium.

AIMS

This review article aims to: (1) provide the biological background necessary to understand the rational for the use of EMD for periodontal regeneration, (2) present animal and human histological evidence of periodontal regeneration following EMD application, (3) provide clinically relevant indications for the use of EMD and (4) discuss future avenues of research including key early findings leading to the development of Osteogain, a new carrier system for EMD specifically developed with better protein adsorption to bone grafting materials.