Preservation of root cementum: a comparative evaluation of power-driven versus hand instruments

Clinical Comparison of Guided Biofilm Therapy and Scaling and Root Planing in the Active Phase of Periodontitis Management

OBJECTIVE

 The aim of this randomized, controlled, split-mouth study was to compare full-mouth air polishing followed by ultrasonic debridement (known as Guided Biofilm Therapy [GBT]) versus traditional Scaling and Root Planing (SRP), in terms of pocket closure in patients with stages III and IV periodontitis.

MATERIALS AND METHODS

 The patients underwent periodontal therapy in two sessions. At the beginning of the first session, quadrants I and IV and II and III were randomly assigned to GBT or SRP treatment. Periodontal parameters were collected at baseline, 6 weeks (T1), and 3 months (T2) after therapy. The primary outcome was the number of experimental sites (pocket probing depth [PPD] >4 and <10 mm) becoming closed pockets (PPD ≤ 4 mm bleeding on probing [BOP] negative) at T1 and T2. Secondary outcomes were PPD, recession, clinical attachment level, BOP, and plaque index variations at the experimental sites and treatment time.

STATISTICAL ANALYSIS

 A 10% difference in the primary outcome between the two protocols was set as the threshold to define inferiority/noninferiority of the test treatment. The primary outcome was modeled using a generalized estimating equation model to account for intrapatient measurement correlation. The estimates are reported as differences between groups' percentages (treatments or time points) and corresponding 95% confidence interval (95% CI). All analyses assumed a significance level of 5%.

RESULTS

 A total of 32 patients were selected. Mean PPD (mm) reduced from 6.23 (6.06-6.40) to 3.33 (3.06-3.61) at T2 for GBT, and from 6.21 (6.04-6.38) to 3.32 (3.11-3.53) at T2 for SRP. Both treatments reached a comparable percentage of closed pockets at T1 (77.9% for GBT vs. 80.1% for SRP, p = 0.235) and T2 (84.1% for GBT vs. 84.4% for SRP, p = 0.878), with no statistically or clinically significant difference. GBT and traditional SRP with ultrasonic and hand instruments reach satisfactory clinical results in the active treatment of patients with stages III and IV periodontitis, with comparable rates of closed pockets and treatment time.

CONCLUSION

 GBT is a suitable option in the active phase of periodontitis management in patients with stages III and IV periodontitis.

In-vitro effect of different instrumentations on adhesion of a multispecies bacterial mixture to root surfaces and the subsequent response of pulpal cells

OBJECTIVES

To investigate in vitro the influence of instrumentation methods on the bacterial colonization of root dentine and pulpal cell behaviour seeded into the pulp cavum.

MATERIALS AND METHODS

Extracted teeth underwent root canal treatment with sealing of apices. The teeth were subjected to periodontal instrumentation using manual, ultrasonic scalers, air polishing, or left untreated. The root surfaces were then incubated with a mixture of six bacterial species for 2 h, 24 h and 10 weeks, before dentine samples were taken and analyzed for bacterial colony forming units (cfu) counts. In an additional series, pulpal cells were seeded into the reopened pulp chambers after 10 weeks of incubation with the bacterial mixture and analysed for interleukin (IL)-8 and matrix metalloprotease (MMP)-3 expression.

RESULTS

After 2 and 24 h of incubation, instrumented dentine samples contained fewer bacteria than the controls (median (log10 cfu): 5.73 vs. 5.92; 7.71 vs. 8.01 (p = 0.007; p = 0.017)). At 24 h, among the instrumentation groups the highest cfu counts were observed in the ultrasonic group (p = 0.012 vs. manual scaler group; p = 0.002 vs. air polishing group). After 10 weeks, the number of viable bacteria (cfu) decreased in all groups with no difference between any group. Pulpal cells seeded in teeth, with or without prior instrumentation, but exposed to the bacterial mixture for 10 weeks, released higher levels of IL-8 and MMP-3 compared to those in uncontaminated and untreated controls.

CONCLUSIONS

Instrumentation initially inhibits bacterial colonisation. Prolonged exposure of the outer root surface to bacteria may increase the inflammatory response of pulpal cells.

CLINICAL RELEVANCE

Regular removal of bacteria from the root surface is supported by these in vitro data.

Management of the endodontic-periodontal lesion

Endodontic-periodontal lesions (EPLs) develop due to the various pathways that allow microbial migration between these two compartments. The authors review the historical and current research on the aetiology, diagnostic pathways, prognostic factors and management strategies for EPLs, emphasising a multidisciplinary approach to managing EPLs. This paper aims to guide clinicians in managing these challenging cases with a combination of endodontic and periodontal therapies.

Response of a Blood Clot Adherent to Bone, Oral Mucosa and Hard Dental Tissues to a Uniaxial Tensile Test: An In Vitro Study

Background and Objectives: Periodontal therapy aims to arrest the progression of periodontal diseases and possibly to regenerate the periodontal apparatus. To shift healing from repair to regeneration, the blood clot that fills the periodontal defect and remains in contact with structures such as tooth root, mucosa and bone needs to be stable, which is a reason why the treatment of non-containing periodontal bone defects, in which the clot may undergo displacement, is challenging. The gingival soft tissue, properly sutured, may act as a wall for blood clot stabilization. Knowledge on the response of the blood clot to stress and how it might vary according to the characteristics of the tissues it gets in contact with might be deepened. The aim of this study was to investigate in vitro, by means of a micro-loading device, the response of the complex formed by a blood clot and diverse tissues, simulating those involved in periodontal regeneration, to a displacing tensile test. Materials and Methods: Experimental samples made of two layers of either hard dental tissues, cancellous bone or oral mucosa, between which fresh blood was interposed, underwent a debonding experiment by means of a micro-loading device that measured their response to uniaxial tensile stress. Results: The peak of tensile stress and the overall work needed for the complete rupture of the clot's fibrin filaments were significantly higher for hard dental tissues than for other tissues. However, mucosa sustained the highest maximal strain in terms of relative displacement between the plates of the micro-loading device to accomplish the complete rupture of the fibrin filaments compared to the other tissues, suggesting that the mucosa might act as a stable interface with the clot and be able to sustain tensile stresses. Conclusions: This in vitro study seems to support the use of mucosa to act as a wall for regenerative procedures of suprabony periodontal defects given its capability to form a stable interface with the clot.

Guided biofilm therapy versus conventional protocol-clinical outcomes in non-surgical periodontal therapy

BACKGROUND

The aim of the randomized controlled clinical trial study was to evaluate the effectiveness in reducing pathologically increased pocket probing depths (PPD > 3 mm) using the Guided Biofilm Therapy (GBT) protocol (adapted to the clinical conditions in non-surgical periodontal therapy (NSPT): staining, air-polishing, ultrasonic scaler, air-polishing) compared to conventional instrumentation (staining, hand curettes/sonic scaler, polishing with rotary instruments) both by less experienced practitioners (dental students).

METHODS

All patients were treated according to a split-mouth design under supervision as diseased teeth of quadrants I/III and II/IV randomly assigned to GBT or conventional treatment. In addition to the treatment time, periodontal parameters such as PPD and bleeding on probing (BOP) before NSPT (T0) and after NSPT (T1: 5 ± 2 months after T0) were documented by two calibrated and blinded examiners (Ethics vote/ Trial-register: Kiel-D509-18/ DRKS00026041).

RESULTS

Data of 60 patients were analyzed (stage III/IV: n = 36/ n = 24; grade A/ B/ C: n = 1/ n = 31/ n = 28). At T1, a PPD reduction of all diseased tooth surfaces was observed in 57.0% of the GBT group and 58.7% of the control group (p = 0.067). The target endpoint (PPD ≤ 4 mm without BOP) was achieved in 11.5% for GBT (conventional treatment: 11.2%; p = 0.714). With the exception for number of sites with BOP, which was at T1 15.9% in the GBT group and 14.3% in the control group (p < 0.05) no significant differences between the outcomes of the study were found. At 30.3(28.3) min, the treatment time was significantly shorter in GBT than in the control group at 34.6(24.5) min (p < 0.001).

CONCLUSIONS

With both protocols (GBT/ conventional instrumentation) comparably good clinical treatment results can be achieve in NSPT in stage III-IV periodontitis patients.

TRIAL REGISTRATION

The study was registered before the start of the study and can be found under the number DRKS00026041 in the German Clinical Trials Register. The registration date was 19/08/2021.

In-vitro effects of novel periodontal scalers with a planar ultrasonic piezoelectric transducer on periodontal biofilm removal, dentine surface roughness, and periodontal ligament fibroblasts adhesion

OBJECTIVES

To compare ultrasonic scaler prototypes based on a planar piezoelectric transducer with different working frequencies featuring a titanium (Ti-20, Ti-28, and Ti-40) or stainless steel (SS-28) instrument, with a commercially available scaler (com-29) in terms of biofilm removal and reformation, dentine surface roughness and adhesion of periodontal fibroblasts.

MATERIALS AND METHODS

A periodontal multi-species biofilm was formed on specimens with dentine slices. Thereafter specimens were instrumented with scalers in a periodontal pocket model or left untreated (control). The remaining biofilms were quantified and allowed to reform on instrumented dentine slices. In addition, fibroblasts were seeded for attachment evaluation after 72 h of incubation. Dentine surface roughness was analyzed before and after instrumentation.

RESULTS

All tested instruments reduced the colony-forming unit (cfu) counts by about 3 to 4 log10 and the biofilm quantity (each p < 0.01 vs. control), but with no statistically significant difference between the instrumented groups. After 24-hour biofilm reformation, no differences in cfu counts were observed between any groups, but the biofilm quantity was about 50% in all instrumented groups compared to the control. The attachment of fibroblasts on instrumented dentine was significantly higher than on untreated dentine (p < 0.05), with the exception of Ti-20. The dentine surface roughness was not affected by any instrumentation.

CONCLUSIONS

The planar piezoelectric scaler prototypes are able to efficiently remove biofilm without dentine surface alterations, regardless of the operating frequency or instrument material.

CLINICAL RELEVANCE

Ultrasonic scalers based on a planar piezoelectric transducer might be an alternative to currently available ultrasonic scalers.

Supra- and sub-gingival instrumentation of periodontitis with the adjunctive treatment of a chloramine - a one-year randomized clinical trial study

Periodontitis is a bacterial-induced disease and for this reason controlling the microbiota is a necessity. Therapy includes self-performed daily oral hygiene in combination with supra- and sub-gingival instrumentation. An adjunctive antimicrobial agent may improve the outcome.

AIMS

To assess whether a chloramine (Perisolv®) has an adjunctive effect to non-surgical periodontal therapy and whether non-surgical periodontal therapy affects quality of life.

MATERIAL AND METHODS

Thirty-eight patients were randomized to a test or a control group. Clinical indices were performed at baseline and at three and twelve months. In the test group, Perisolv® was applied initially and after the sub-gingival instrumentation in pathological pockets. Oral health-related quality of life was measured with the Oral Health Impact Profile (OHIP) instrument at baseline and twelve months.

RESULTS

In both groups, an initial probing pocket depth (PPD) of > 4 mm and bleeding on probing (BOP) were statistically reduced (p < 0.002 and p < 0.002 respectively) at twelve months and after adjustment for Bonferroni. There were no significant differences between the test and the control group in terms of the number of PPD, BOP or plaque index, or in the mean OHIP score.

CONCLUSIONS

Chloramine did not have an adjunctive effect, but the overall therapy was significantly efficacious both clinically and in terms of quality of life.

TRIAL REGISTRATION

Registered at www.

CLINICALTRIALS

gov:NCT05757921.

Effects of a new magnetostrictive ultrasonic scaler and a traditional piezoelectric ultrasonic scaler on root surfaces and patient complaints

Tooth wear and pain are the primary concerns of patients undergoing periodontal scaling. The aims of this study were to compare the effects of a new magnetostrictive ultrasonic scaler and a traditional piezoelectric ultrasonic scaler on tooth surface roughness and calculus removal and to determine their impacts on patient discomfort during supragingival cleaning. This article had two parts: an in vitro study and a clinical study. In the in vitro study, thirty teeth with subgingival calculus were randomly assigned to two scaling treatment groups: magnetostrictive scalers (n = 15) and piezoelectric scalers (n = 15). Surface roughness measurements were taken at baseline and after scaling, and the root samples were visualised by SEM after scaling. Additionally, a single-centre randomised split-mouth clinical trial was conducted. Eighty-five participants diagnosed with chronic gingivitis or periodontitis were randomly assigned to receive supragingival scaling. The magnetostrictive scaler was used in half of the mouths (n = 85), and the piezoelectric scaler was used in the other half of the mouths (n = 85). Data on pain, noise, and vibration were collected using a VAS questionnaire, and the operating time was recorded. In both in vitro and clinical studies, magnetostrictive scalers were reported to be more effective than piezoelectric scalers in removing dental deposits (P < 0.05). Additionally, the root surface after scaling with the magnetostrictive scaler was smoother than that after scaling with the piezoelectric scaler in the in vitro study (P = 0.02). SEM examination also revealed that fewer dental materials were lost after instrumentation with the magnetostrictive scaler than after instrumentation with the piezoelectric scaler. Piezoelectric scalers caused less discomfort to patients in terms of pain, noise, and vibration than magnetostrictive scalers (P < 0.05). According to this clinical study, the magnetostrictive scaler caused more discomfort during supragingival scaling than the piezoelectric scaler. Moreover, the magnetostrictive scaler was also more efficient and produced a smoother root surface with less material loss after scaling than the piezoelectric scaler, as demonstrated in the in vitro study.

New insights into nanotherapeutics for periodontitis: a triple concerto of antimicrobial activity, immunomodulation and periodontium regeneration

Periodontitis is a chronic inflammatory disease caused by the local microbiome and the host immune response, resulting in periodontal structure damage and even tooth loss. Scaling and root planning combined with antibiotics are the conventional means of nonsurgical treatment of periodontitis, but they are insufficient to fully heal periodontitis due to intractable bacterial attachment and drug resistance. Novel and effective therapeutic options in clinical drug therapy remain scarce. Nanotherapeutics achieve stable cell targeting, oral retention and smart release by great flexibility in changing the chemical composition or physical characteristics of nanoparticles. Meanwhile, the protectiveness and high surface area to volume ratio of nanoparticles enable high drug loading, ensuring a remarkable therapeutic efficacy. Currently, the combination of advanced nanoparticles and novel therapeutic strategies is the most active research area in periodontitis treatment. In this review, we first introduce the pathogenesis of periodontitis, and then summarize the state-of-the-art nanotherapeutic strategies based on the triple concerto of antibacterial activity, immunomodulation and periodontium regeneration, particularly focusing on the therapeutic mechanism and ingenious design of nanomedicines. Finally, the challenges and prospects of nano therapy for periodontitis are discussed from the perspective of current treatment problems and future development trends.

Subgingival Use of Air-Polishing Powders: Status of Knowledge: A Systematic Review

Effective subgingival biofilm removal is crucial for achieving positive and stable outcomes in periodontal therapy, forming an indispensable part of any periodontal treatment approach. The development of air-polishing tools has emerged as a promising alternative to hand and ultrasonic scalers for dental biofilm removal. The objective of this systematic review was to assess existing literature regarding the subgingival use of various types of air-polishing powders, as an effective method of subgingival biofilm control. For this, 55 articles on this subjected were sourced from searched databases and subjected to an evaluation process of their contained information, which was subsequently structured and compiled into this manuscript. The existing literature acknowledges that good subgingival biofilm control is essential for the success of periodontal therapy, including through subgingival air-polishing, as an adjunctive procedure. This approach has the potential to enhance patient comfort during and after subgingival mechanical plaque removal, thereby mitigating damage to periodontal structures. Consequently, it may lead to improved healing capabilities within the periodontal tissues and the formation of a more stable reparative gingival junctional epithelium.

The efficacy of subgingival air polishing and subgingival debridement in periodontal support therapy: a meta-analysis

OBJECTIVE

To assess whether there is sufficient evidence of a difference in efficacy between subgingival air polishing (SubAP) and subgingival debridement as periodontal support treatment. The systematic review protocol was registered in the PROSPERO database under no. CRD42020213042.

METHODS

A comprehensive search was conducted using eight online databases to develop straightforward clinical questions and search strategies, from their inception to 27 January 2023. The references of identified reports were also retrieved for inclusion in the analysis. The risk-of-bias of the included studies was evaluated using the Revised Cochrane Risk-of-Bias tool (RoB 2). A meta-analysis was performed on five clinical indicators using the Stata 16 software.

RESULTS

Twelve randomized controlled trials were ultimately included, and most included studies had varying degrees of risk-of-bias. The results of the meta-analysis indicated that there was no significant difference between SubAP and subgingival scaling in terms of improving probing depth (PD), clinical attachment loss (CAL), plaque index (PLI), and bleeding on probing% (BOP%). The results of the visual analogue scale score analysis indicated that SubAP produced less discomfort than did subgingival scaling.

DISCUSSION

SubAP can provide better treatment comfort than subgingival debridement. There was no significant difference in the efficacy of the two modalities in improving PD, CAL, and BOP% in supportive periodontal therapy.

CONCLUSION

Currently, evidence for assessing the difference in the efficacy of SubAP and subgingival debridement in improving the PLI is insufficient, and further high-quality clinical studies are needed.

A facile method for rejuvenating the bonding efficacy of root canal sealer-smeared dentine

OBJECTIVES

To examine the efficacy of glycine powder air-polishing on cleaning root canal sealer-smeared dentine.

METHODS

Dentine surfaces were contaminated with a smear of epoxy resin-based sealer or tricalcium silicate-based sealer. The contaminated surfaces were cleaned with saline, 75% ethanol, or air-polishing with glycine powder. Uncontaminated dentine was used as the control. The cleanliness of pulpal floor dentine was examined using scanning electron microscopy and energy dispersive X-ray analysis. The effectiveness of the three cleaning protocols was examined by testing the tensile bond strength of a self-etching adhesive to the decontaminated dentine. Resin infiltration into the dentinal tubules was identified using confocal laser scanning microscopy (CLSM).

RESULTS

Morphological examination and elemental analysis indicated that glycine powder air-polishing was more effective in removing the two sealers. Tensile bond strength of adhesive-bonded dentine was significantly reduced when either sealer was cleaned with saline or ethanol. Conversely, air-polishing restored the adhesive strength of the sealer-smeared dentine to the level of the control. Longer and denser resin tags were identified with CLSM when sealers were removed with air-polishing.

CONCLUSIONS

Air-polishing with glycine powder was effective in cleaning sealer-smeared dentine, as demonstrated by the rejuvenation of the tensile bond strength of a self-etching adhesive to the decontaminated dentine.

CLINICAL SIGNIFICANCE

Glycine powder air-polishing improves the cleanliness of root canal sealer-smeared dentine and rejuvenates adhesive bonding effectiveness.

A Novel Piezoelectric-Assisted Non-Surgical Periodontal Treatment: A Prospective Case Series

The purpose of this study was to evaluate the clinical efficacy of a non-surgical periodontal treatment using a piezoelectric power-driven device with a novel insert. Plaque index (PlI), bleeding on probing (BoP), probing depth (PD), recession depth (Rec) and clinical attachment level (CAL) were assessed at 6 weeks, 3 months and 6 months. Furthermore, tooth mobility and furcation involvement were recorded and chewing discomfort and dental hypersensitivity were evaluated. Eighteen stage I to IV periodontitis patients providing 437 teeth and 2622 sites in total were analyzed. At six weeks, CAL gain (0.4; p < 0.0001), PD reduction (0.4; p < 0.0001) and Rec increase (0.1; p = 0.0029) were statistically significant. Similarly, the mean number of sites with PD > 4 mm and absence of BoP significantly decreased between baseline and 6 weeks (-12.7; p < 0.0001). At this time point, the patient's chewing discomfort was also significantly diminished (1.4; p = 0.0172). Conversely, no statistically significant changes were observed between 6 weeks and 3 months and between 3 months and 6 months for any of the clinical variables evaluated. In conclusion, within the limitation of this study, mechanical piezo-assisted non-surgical periodontal treatment in conjunction with an innovative tip resulted significantly efficacious to reduce pathological periodontal pockets, to gain clinical attachment and to reduce gingival inflammation.

Complications and treatment errors in nonsurgical periodontal therapy

Nonsurgical periodontal therapy can be subject to iatrogenesis, which includes all the complications directly or indirectly related to a treatment. These complications include both operator-dependent harms and errors and the consequences and adverse effects of the therapeutic procedures. The complications arising following nonsurgical periodontal treatment can be categorized as intraoperative and postoperative and can affect both soft and hard tissues at an intra-oral and extraoral level. Soft-tissues damage or damage to teeth and restorations can occur while performing the procedure. In the majority of cases, the risk of bleeding associated with nonsurgical therapy is reported to be low and easily controlled by means of local hemostatic measures, even in medicated subjects. Cervicofacial subcutaneous emphysema is not a frequent extraoral intraoperative complication, occurring during the use of air polishing. Moreover, side effects such as pain, fever, and dentine hypersensitivity are frequently reported as a consequence of nonsurgical periodontal therapy and can have a major impact on a patient's perception of the treatment provided. The level of intraoperative pain could be influenced by the types of instruments employed, the characteristics of tips, and the individual level of tolerance of the patient. Unexpected damage to teeth or restorations can also occur as a consequence of procedural errors.

The endodontic-periodontal juncture: Where two worlds meet. An overview of endo-perio lesions

Endodontic and periodontal infections can be difficult to differentiate from one another and often share common clinical features making diagnosis challenging. The aim of this review is to discuss endodontic and periodontal infections in situations where they occur concurrently, or where one influences the other. The available literature investigating endodontic and periodontal infections was examined for contemporary knowledge regarding endodontic-periodontal interactions. Strategies to facilitate diagnosis and treatment planning are discussed. When endodontic and periodontal infections occur together, or signs and symptoms are similar, diagnosis can be challenging. Determining the primary source of infection is imperative to ensure appropriate treatment planning. The pulp and periodontal tissues are intimately related, with many possible pathways for infection from one to the other. Diagnosis of the primary source of the infection can be difficult and sometimes an inter-disciplinary approach to treatment is required. © 2023 Australian Dental Association.

Assessment of the Periodontal Cementum Ablation Depth during Root Planing by an Er:YAG Laser at Different Energy Densities: An Ex Vivo Study

INTRODUCTION

An important and non-adapted delivered energy of Er:YAG laser can eliminate the total thickness of root cementum during root planing. Conversely, the preservation of a partial layer of cementum covering the roots is vital for any periodontal ligament regeneration. Thus, the assessment of the cementum ablation depth produced by each energy density of Er:YAG laser is essential before considering its use for the periodontal planing and treatment of the cementum and root surfaces.

AIM OF THE STUDY

Assessment of the cementum ablation depth at different energy densities of the Er:YAG laser is the aim of this study.

MATERIALS AND METHODS

A total of 48 human caries free molars were collected and used in this study. Areas to be irradiated were delimited by two longitudinal grooves (0.5 mm depth). Roots were divided randomly into four groups (4 × n = 12). An Er:YAG laser (2.94 µm) was used with a side-firing tip (R600T) with a 600 µm diameter and a frequency of 20 Hz combined with a cooling system of air 6 mL/min and water 4 mL/min. We used a super short pulse mode (SSP: pulse duration: 50 μs). We used a single irradiation passage backward from apex to cervical parts at 1 mm/s with a slight contact and at an angle of 15° to 30° between the tip and the root surface. Different energies were selected: 30 mJ, 40 mJ, 50 mJ, and 60 mJ.

RESULTS

Microscopic observations showed that the average of the ablation depth increased with the increase of the delivered energy from 30 mJ to 60 mJ. Mean values of the ablation depths were respectively as follows: 43.75 ± 4.89 µm for the energy of 30 mJ, 50.05 ± 3.72 µm for 40 mJ, 65.56 ± 10.35 µm for 50 mJ, and 74.80 ± 15.23 µm for 60 mJ. A statistically significant difference existed between the ablation depth of all groups.

CONCLUSION

Based on our results, the depth of cementum debridement is related to the level of the delivered energy. The lowest energy levels (30 mJ and 40 mJ) can ablate the root cementum surface for a variable depth from 43.75 ± 4.89 μm to 50.05 ± 3.72 μm.

A Local Desiccant Antimicrobial Agent as an Alternative to Adjunctive Antibiotics in the Treatment of Periodontitis: A Narrative Review

Periodontitis is one of the most common oral polymicrobial infectious diseases induced by the complex interplay between the altered subgingival microbiota and the host’s dysregulated immune-inflammatory response, leading to the initiation of progressive and irreversible destruction of the periodontal tissues and eventually to tooth loss. The main goal of cause-related periodontal therapy is to eliminate the dysbiotic subgingival biofilm in order to arrest local inflammation and further periodontal tissue breakdown. Because, in some cases, subgingival mechanical instrumentation has limited efficiency in achieving those goals, various adjunctive therapies, mainly systemic and locally delivered antimicrobials, have been proposed to augment its effectiveness. However, most adjunctive antimicrobials carry side effects; therefore, their administration should be precociously considered. HybenX® (HY) is a commercial therapeutical agent with decontamination properties, which has been studied for its effects in treating various oral pathological conditions, including periodontitis. This review covers the current evidence regarding the treatment outcomes and limitations of conventional periodontal therapies and provides information based on the available experimental and clinical studies related to the HY mechanism of action and effects following its use associated with subgingival instrumentation and other types of dental treatments.

The early wear susceptibility of cementum, enamel and dentine in vitro

OBJECTIVES

To assess the differential early wear susceptibility of cementum, enamel and dentine at a micron level.

METHODS

Whole human molar buccal surfaces incorporating natural enamel and cementum (n = 20) confirmed by imaging (digital microscopy: Keyence, VHX-7000 Milton Keynes, UK), were mounted, scanned (profilometry: XYRIS 4000, Taicaan, Southampton, UK), and allocated to receive erosion (citric acid, pH 2.7, 30 min (n = 10)) or erosion/abrasion challenges (3 cycles of (citric acid, pH 2.7, 10 min, 60 300 g linear abrasion strokes), n=10). Samples were polished and the experiment repeated on polished enamel, and polished coronal and radicular dentine within the same tooth. Profilometric wear data were obtained using superimposition: GeoMagic (3Dsystems, Darmstadt, Germany) and subtraction: MountainsMap (DigitalSurf, Besancon, France). Data were normal. A general linear model was used to assess differences between groups and substrates.

RESULTS

The mean step height (SD) for natural enamel was 8.82 μm (2.53) for erosion and 11.48 μm (2.95) for erosion/abrasion. For natural cementum, the mean step height was 6.00 μm (2.29) for erosion and 4.67 μm (1.58) for erosion/abrasion. Dentine step heights ranged from 7.20 μm (1.53) for erosion and 9.79 μm (1.01) for erosion/abrasion with no statistical differences in dentine wear. Natural cementum surfaces had the lowest wear (p<0.001). Dentine had significantly less wear than natural enamel (p<0.02).

CONCLUSIONS

Cementum surfaces demonstrated the most wear resistance, followed by dentine under erosion dominant conditions in this in vitro study. Further in-vivo investigations are needed to confirm the intraoral stability of cementum.

CLINICAL SIGNIFICANCE

Cementum may be the least susceptible of dental substrates to wear and dentine does not wear at a faster rate than enamel under erosive conditions. This adds to our knowledge on the development of non-carious cervical lesions and questions whether wear rates will accelerate once dentine is exposed.

The effectiveness of scaling and root planing with combined application of air polishing and Nd:YAG laser in periodontal pockets of stage III grade C periodontitis patients: a single-blinded randomized clinical trial

OBJECTIVES

Evaluating the efficiency of combined air polishing and Nd:YAG laser application in addition to scaling and root planning (SRP) in treatment of periodontal pockets of stage III grade C periodontitis patients was the aim of this clinical trial.

MATERIALS AND METHODS

Twenty-four systemically healthy, stage III grade C periodontitis patients were recruited for this clinical trial. In this split-mouth study, the quadrants were randomly allocated to either SRP with combined air polishing (erythritol/chlorhexidine powder) and Nd:YAG laser (2 W, 200 mJ/pulse, 10 Hz) therapy (test group) or SRP alone (control group). A masked examiner recorded clinical parameters such as plaque index (PI), gingival index (GI), bleeding on probing (%) (BOP %), probing depth (PD), and clinical attachment level (CAL) on periodontal charts at baseline, 1 month and 3 months after treatment.

RESULTS

The clinical parameters had significantly reduced 1 and 3 months after treatment compared to baseline for both study groups (p < 0.05). Considering PI, GI, and BOP (%) parameters, there were no significant differences between the study groups at any time points (p > 0.05). While PD and CAL reductions were similar in study groups for moderately deep pockets (5 to 6 mm) (p > 0.05), PD and CAL reductions were significantly greater in test group compared to control group for deep pockets (PD ≥ 7 mm) (p < 0.05).

CONCLUSIONS

The present clinical trial demonstrated that SRP with combined application of air polishing and Nd:YAG laser may be advantageous in sites where mechanical debridement alone cannot access, such as deep pockets in the short term. Long-term, well-designed future studies including clinical, biochemical, and microbiological analyses are needed to determine the effectiveness of this procedure.

CLINICAL RELEVANCE

SRP with combined application of air polishing and Nd:YAG laser provided more reductions in probing depth and clinical attachment level parameters in deep pockets compared to SRP alone.

Fusobacterium nucleatum Subspecies Differ in Biofilm Forming Ability in vitro

Development of dysbiosis in complex multispecies bacterial biofilms forming on teeth, known as dental plaque, is one of the factors causing periodontitis. Fusobacterium nucleatum (F. nucleatum) is recognised as a key microorganism in subgingival dental plaque, and is linked to periodontitis as well as colorectal cancer and systemic diseases. Five subspecies of F. nucleatum have been identified: animalis, fusiforme, nucleatum, polymorphum, and vincentii. Differential integration of subspecies into multispecies biofilm models has been reported, however, biofilm forming ability of individual F. nucleatum subspecies is largely unknown. The aim of this study was to determine the single-subspecies biofilm forming abilities of F. nucleatum ATCC type strains. Static single subspecies F. nucleatum biofilms were grown anaerobically for 3 days on untreated or surface-modified (sandblasting, artificial saliva, fibronectin, gelatin, or poly-L-lysine coating) plastic and glass coverslips. Biofilm mass was quantified using crystal violet (CV) staining. Biofilm architecture and thickness were analysed by scanning electron microscopy and confocal laser scanning microscopy. Bioinformatic analysis was performed to identify orthologues of known adhesion proteins in F. nucleatum subspecies. Surface type and treatment significantly influenced single-subspecies biofilm formation. Biofilm formation was overall highest on poly-L-lysine coated surfaces and sandblasted glass surfaces. Biofilm thickness and stability, as well as architecture, varied amongst the subspecies. Interestingly, F. nucleatum ssp. polymorphum did not form a detectable, continuous layer of biofilm on any of the tested substrates. Consistent with limited biofilm forming ability in vitro, F. nucleatum ssp. polymorphum showed the least conservation of the adhesion proteins CmpA and Fap2 in silico. Here, we show that biofilm formation by F. nucleatum in vitro is subspecies- and substrate-specific. Additionally, F. nucleatum ssp. polymorphum does not appear to form stable single-subspecies continuous layers of biofilm in vitro. Understanding the differences in F. nucleatum single-subspecies biofilm formation may shed light on multi-species biofilm formation mechanisms and may reveal new virulence factors as novel therapeutic targets for prevention and treatment of F. nucleatum-mediated infections and diseases.

Effect of Twinlight Laser on the Attachment of Human Gingival Fibroblasts to the Root Surface In Vitro

Background

This study aimed to compare the effectiveness of subgingival scaling and root planing with the Twinlight laser, Er: YAG laser, and hand instrumentation on the removal of endotoxin and attachment of human gingival fibroblasts (HGFs) to cementum surfaces in vitro.

Material/Methods

Single-rooted teeth extracted for periodontal disease were collected and divided into 3 groups: group A, root planing with Gracey curet no. 5/6; group B, irradiation with Er: YAG laser; group C, irradiation with Er: YAG laser and Nd: YAG laser. Endotoxins were determined by the limulus amebocyte lysate test. Cell attachment and proliferation of HGFs on root specimens were evaluated by cell counting kit-8 assay. The root surface and cell morphology were observed by scanning electron microscope.

Results

A flat root surface with scratches was found in group A, Group B had a homogeneous rough morphology without carbonization, and group C had a non-homogeneous rough morphology with ablation. The endotoxin concentration was highest in group A (P<0.05) and lowest in group C (P>0.05). HGFs cultured in group B showed significantly increased adhesion and proliferation compared with groups A and C (P<0.05). HGFs in group B were well attached, covered densely by pseudopodia. HGFs in group A were round with poor extension and short pseudopodia, while the cells in the group C were in narrow, triangular, or polygonal shapes.

Conclusions

Twinlight laser-assisted periodontal treatment effectively improved the biocompatibility of root surface and promoted the attachment and proliferation of fibroblasts by removing calculus and reducing the concentration of endotoxins.

Comparison of friction of metallic and ceramic brackets during sliding mechanics after prophylaxis with sodium bicarbonate jet: An in vitro study

OBJECTIVE

An in vitro experimental study was carried out with the objective to compare the friction in aesthetic and metallic brackets after prophylaxis with sodium bicarbonate jet during sliding mechanics.

MATERIAL AND METHODS

Aesthetic monocrystalline (n=24) and polycrystalline (n=24) and metallic brackets (n=24) were used. Each group of brackets was divided into two groups, as follows: the first group received prophylaxis with a bicarbonate jet, while the second group did not. An acrylic plate was attached to the base fixature of the Instron 4411 universal testing machine, simulating the retraction movement of the canine during sliding mechanics. The bracket was pulled at a speed of 0.5mm/minute over a distance of 0.5mm. The data were analysed by analysis of variance (ANOVA) and Tukey test.

RESULTS

After the sodium bicarbonate jet, conventional metal brackets showed less friction (P<0.05). While the aesthetic brackets did not show significant difference in friction between the exposed and non-exposed groups with the sodium bicarbonate jet (P>0.05), the polycrystalline brackets showed greater friction when compared to the other groups of brackets.

CONCLUSIONS

It was concluded that prophylaxis with sodium bicarbonate jet did not influence the resistance to friction in aesthetic brackets; however, metal brackets showed a significant decrease in friction after prophylaxis with sodium bicarbonate jet. Our results suggest that the abrasion of the sodium bicarbonate particles can cause micromorphological changes, which may influence the friction; however, studies with scanning electron microscopy are necessary.

Clinical and radiographic evaluation of demineralized freeze-dried bone allograft with concentrated growth factor versus concentrated growth factor alone in the treatment of intrabony defects

BACKGROUND

Periodontal disease is one of the major causes of alveolar bone loss. There are various ways of regenerating the lost bone, i.e. guided tissue regeneration, bone grafts, and growth factors. In this purview, it becomes immensely important for a clinician to decide the best modality of treatment. In this study, we compared the effect of demineralized freeze-dried bone allograft (DFDBA) in combination with concentrated growth factors (CGF) verses CGF alone.

METHODS

This double-blind, split-mouth study was conducted on ten patients with two comparable bilateral intrabony defects. Each pair of defects was randomly treated by DFDBA + CGF or CGF alone. Clinical parameters such as plaque index (PI), modified gingival index (MGI), pocket probing depth (PPD), and relative attachment level (RAL) were recorded at baseline, three months, and six months. In addition, radiograph with grids was also taken at baseline and six months. The paired t-test was used to compare the pre- and post-treatment values and the unpaired t-test was used to compare the test and control group.

RESULTS

The PI score decreased significantly from baseline to six months. Similarly, the mean MGI score decreased significantly from baseline to six months. The intragroup comparison showed that there was a significant reduction in PPD in both the test and control group. However, the intergroup comparison showed that the reduced pocket depth was not significant. The intragroup radiographic comparison showed that there was the significant formation of bone in both the test and control group but inter-group showed that the formation of bone among both the group were non-significant.

CONCLUSION

Radiographic and clinical outcomes of this study concluded that post six months, both groups demonstrated significant improvement in clinical and radiographic parameters. However, the addition of DFDBA to CGFs did not give any additional benefits.

Clinical, inflammatory and microbiological outcomes of full-mouth scaling with adjunctive glycine powder air-polishing: A randomized trial

AIM

To determine the effects of glycine powder air-polishing (GPAP) as an adjunct to full-mouth scaling and root planing (SRP) on clinical, inflammatory and microbiological outcomes in patients with untreated periodontitis.

MATERIALS AND METHODS

Forty-one patients were randomly assigned to the control group A (SRP) and test groups B1 (subgingival GPAP right after SRP) and B2 (subgingival GPAP right before SRP). Clinical examinations and sample collections (saliva, subgingival plaque, serum and gingival crevicular fluid) were performed at assessment visits and before therapies at clinical visits of baseline, 6-week and 3-month. C-reactive protein, IL-6 and TNF-α were assessed in serum and gingival crevicular fluid, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum were measured in saliva and subgingival plaque.

RESULTS

Patients in control and test groups did not significantly differ by age, sex and disease severity at baseline. Participants in control and intervention groups had similar improvements in clinical parameters (PD, BOP, PLI and BI). All groups had a similar percentage of sites showing PD reduction of ≥2 mm between baseline and follow-up visits, with a few exceptions. Reduced C-reactive protein, IL-6 and TNF-α in serum were found after treatments.

CONCLUSION

Full-mouth SRP with and without GPAP resulted in largely similar clinical, inflammatory and microbiological outcomes in the care of untreated periodontitis.

Efficacy of the additional use of subgingival air polishing with erythritol powder in the treatment of periodontitis patients: a randomized controlled clinical trial

OBJECTIVES

To date, scarce evidence exists around the application of subgingival air polishing during treatment of severe periodontitis. The aim of this study was to evaluate the benefits of subgingival air polishing during non-surgical treatment of deep bleeding pockets in stages III-IV periodontitis patients MATERIALS AND METHODS: Forty patients with stages III-IV periodontitis were selected, and pockets with probing depth (PD) 5-9 mm and bleeding on probing (BoP) were selected as experimental sites. All patients underwent a full-mouth session of erythritol powder supragingival air polishing and ultrasonic instrumentation. Test group received additional subgingival air polishing at experimental sites. The proportion of experimental sites shifting to PD ≤ 4 mm and no BoP at 3 months (i.e., non-bleeding closed pockets, NBCPs) was regarded as the primary outcome variable.

RESULTS

The proportion of NBCP was comparable between test and control group (47.9 and 44.7%, respectively). Baseline PD of 7-9 mm, multi-rooted teeth and the presence of plaque negatively influenced the probability of obtaining NBCP.

CONCLUSIONS

The additional application of subgingival air polishing does not seem to provide any significant clinical advantage in achieving closure at moderate to deep bleeding pockets in treatment of stages III-IV periodontitis patients. The study was registered on Clinical Trials.gov (NCT04264624).

CLINICAL RELEVANCE

While air polishing can play a role in biofilm removal at supragingival and shallow sites, ultrasonic root surface debridement alone is still the choice for initial treatment of deep bleeding periodontal pockets.

Efficacy of glycine powder air-polishing in supportive periodontal therapy: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis was conducted to assess the effects of glycine powder air-polishing (GPAP) in patients during supportive periodontal therapy (SPT) compared to hand instrumentation and ultrasonic scaling.

METHODS

The authors searched for randomized clinical trials in 8 electronic databases for relevant studies through November 15, 2019. The eligibility criteria were as follows: population, patients with chronic periodontitis undergoing SPT; intervention and comparison, patients treated by GPAP with a standard/nozzle type jet or mechanical instrumentation; and outcomes, bleeding on probing (BOP), patient discomfort/pain (assessed by a visual analogue scale [VAS]), probing depth (PD), gingival recession (Rec), plaque index (PI), clinical attachment level (CAL), gingival epithelium score, and subgingival bacteria count. After extracting the data and assessing the risk of bias, the authors performed the meta-analysis.

RESULTS

In total, 17 studies were included in this study. The difference of means for BOP in patients who received GPAP was lower (difference of means: -8.02%; 95% confidence interval [CI], -12.10% to -3.95%; P<0.00001; I²=10%) than that in patients treated with hand instrumentation. The results of patient discomfort/pain measured by a VAS (difference of means: -1.48, 95% CI, -1.90 to -1.06; P<0.001; I²=83%) indicated that treatment with GPAP might be less painful than ultrasonic scaling. The results of PD, Rec, PI, and CAL showed that GPAP had no advantage over hand instrumentation or ultrasonic scaling.

CONCLUSIONS

The findings of this study suggest that GPAP may alleviate gingival inflammation more effectively and be less painful than traditional methods, which makes it a promising alternative for dental clinical use. With regards to PD, Rec, PI, and CAL, there was insufficient evidence to support a difference among GPAP, hand instrumentation, and ultrasonic scaling. Higher-quality studies are still needed to assess the effects of GPAP.

The systemic inflammatory response following hand instrumentation versus ultrasonic instrumentation-A randomized controlled trial

OBJECTIVE

This study sought to investigate whether the immediate systemic inflammatory response following full-mouth debridement differs following use of hand compared with ultrasonic instruments.

METHODS

Thirty-nine periodontitis patients were randomized to treatment with full-mouth debridement using either hand or ultrasonic instrumentation completed within 24 hr. Serum and periodontal clinical parameters were collected at baseline, day 1, day 7 and day 90 post-treatment. Differences in systemic inflammatory markers were assessed using general linear models at each timepoint, corrected for age, gender, smoking status, body mass index and baseline levels of each marker.

RESULTS

Across all patients, serum C-reactive protein increased at day 1, with no differences between hand and ultrasonic groups (p(adjusted) = .22). There was no difference between groups in interleukin-6 (p(adjusted) = .29) or tumour necrosis factor α (p(adjusted) = .53) at day 1. Inflammatory markers returned to baseline levels by day 7. Treatment resulted in equal and marked improvements in clinical parameters in both groups; however, total treatment time was on average shorter for ultrasonic instruments (p(adjusted) = .002).

CONCLUSIONS

Ultrasonic instrumentation resulted in shorter treatment time with comparable clinical outcomes. Levels of serum C-reactive protein at day 1 were similar following debridement with hand or ultrasonic instruments.

In vitro characteristics of human periodontal ligament stem cells incubated with boric acid

OBJECTIVES

To evaluate the influence of boric acid (BA) on various aspects of the human periodontal ligament stem cells (hPDLSCs), including proliferation, migration, and adhesion.

METHODS

BA was prepared at increasing concentrations of 0.5%, 0.75%, 1%, 1.5%, 3%, and 6%, and an [3-(4,5-dimethylthiazol-2-YL)-2,5-diphenyl] (MTT) assay was used to determine the non-toxic concentrations of BA on hPDLSCs. The appropriate concentrations of BA were applied in subsequent experiments to evaluate its effect on three particular aspects of hPDLSCs: proliferation, migration, and adhesion. The proliferation of hPDLSCs was determined with a hemocytometer. The migration of hPDLSCs was evaluated using a scratch assay, followed by analysis of the recorded digital images using the Image-Analysis J 1.51j8 software. The adhesion of hPDLSCs to sterilized root surfaces that retained or lacked a cementum was assessed using the MTT assay.

RESULTS

Non-toxic concentrations of BA against hPDLSCs were 0.5% and 0.75%, allowing a relative growth rate of greater than 75%. Treated hPDLSCs proliferated and migrated uneventfully, with no significant differences to the control group. hPDLSCs adhered to both types of the prepared root surfaces; however, those lacking a cementum allowed more effective adhesion than those retaining it. Qualitatively, the adhesion ability of hPDLSCs was better in the 0.5% rather than the 0.75% BA-treated or control groups.

CONCLUSIONS

BA at concentrations of 0.5% and 0.75% did not impede the proliferation, migration, or adhesion ability of hPDLSCs to root surfaces, indicating that this sterilizing agent could be advanced to clinical trials.

Image-Guided Ablation of Dental Calculus From Root Surfaces Using a DPSS Er:YAG Laser

BACKGROUND AND OBJECTIVES

Recent studies have demonstrated that near-infrared (IR) imaging can be used to acquire high-contrast images of root caries and calculus on the root surfaces of extracted teeth at wavelengths longer than 1450 nm. The purpose of this study was to determine if image-guided laser ablation can be used to selectively remove calculus from tooth surfaces with minimal damage to the underlying sound cementum and dentin.

MATERIALS AND METHODS

In this study, sequential near-IR images at 1500-1700 nm were used to guide a diode-pumped (DPSS) Er:YAG laser for the removal of calculus from the root surfaces of 10 extracted teeth. The selectivity of removal was assessed using digital microscopy, optical coherence tomography, and surface profilometry.

RESULTS

Calculus was removed rapidly with minimal damage to the underlying sound cementum and dentin. Image-guided ablation achieved high-selectivity, the mean volume of calculus removal was more than 27 times higher than the mean loss of cementum.

CONCLUSIONS

We have demonstrated that near-IR image-guided laser ablation can be used for the selective removal of calculus from root surfaces ex vivo. Additionally, we have demonstrated that a diode-pumped solid-state Er:YAG laser is well suited for selective removal. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Calculus Removal and Root Surface Roughness When Using the Er:YAG or Er,Cr:YSGG Laser Compared with Conventional Instrumentation Method: A Literature Review

Objective: The purpose of this literature review was to evaluate the effectiveness of using Er:YAG (erbium-doped yttrium/aluminum/garnet) laser or Er,Cr:YSGG (erbium, chromium-doped yttrium/scandium/gallium/garnet) laser on calculus removal and their effect on the topography and roughness of root surface in comparison with the conventional instruments in the nonsurgical periodontal therapy. Background data: One of the most challenging problems in treatment of periodontal disease is the elimination of plaque and calculus, leaving a clean and smooth root surface to decrease plaque and calculus retention, and for good gingival reattachment. Materials and methods: PubMed and Google Scholar were searched for available literature. The electronic search was limited to articles published in the period between January 2007 and April 2017, in the English language. Results: A total of 47 publications fulfilled the inclusion criteria of this systematic review and screened according to the research questions. Calculus removal using the ultrasonic instrument showed remaining calculus compared with the hand instrument, whereas, on the contrary, erbium lasers revealed no remaining calculus or smaller amounts compared with the conventional instruments when used in appropriate settings. The results of this review showed that ultrasonic instrumentation produced effects on the root surface almost similar to that of hand instrumentation. Er:YAG laser and Er,Cr:YSGG laser clarify a little more surface roughness when compared with conventional instruments. Conclusions: The present systematic review indicates that a combination of scaling and root planing (SRP) using the erbium lasers as an adjunctive therapy at certain parameters can be appropriate to remove residual debris from the root surface and at the same time have little or no negative thermal effect on the root surface. The Er:YAG laser also seems to be the most suitable for nonsurgical periodontal therapy. Additional new good-designed studies are needed to evaluate the effectiveness of erbium lasers with SRP in nonsurgical periodontal therapy.

The effect of a 3% hydroxyapatite paste prophylaxis after different root-scaling procedures in periodontics

Abstract Introduction Root-scaling procedures on the root surface show to increase root surface roughness during instrumentation. The use of a prophylactic paste reduces the roughness. Objetive This study evaluated the influence of prophylaxis paste on the surface roughness of root dentin after hand instruments (HI), ultrasonic scalers (US) and rotational instruments (RI) were applied to root surfaces. Material and method Fifty bovine roots were prepared and randomly divided into 10 groups (n=5) in which instrumentation with HI, US, or RI was carried out with or without prophylaxis using either conventional or 3% hydroxyapatite paste; additionally, a control group without treatment was included. The Ra and Rz roughness values were measured using a perfilometer. The morphological aspects of the root surfaces were analysed qualitatively by scanning electron microscopy (SEM). Data were analysed using two-way ANOVA followed by Tukey’s test (α = 0.05). Result The scaling method and the prophylaxis procedure significantly influenced (p < 0.05) root surface roughness. Treatment with US and prophylaxis with 3% hydroxyapatite paste resulted in lower values of Ra (0.14 μm ± 0.02 μm) and Rz (0.89 μm ± 0.18 μm) compared to the other groups. SEM analysis showed smoother and more homogeneous surfaces in the groups with prophylaxis compared to the groups without prophylaxis. There were no substantial differences between the results of applying different pastes. Conclusion The prophylaxis procedure performed with the experimental paste containing 3% hydroxyapatite reduced the roughness of root surfaces treated with HI, US and RI at the same level as the conventional prophylactic paste.

Volumetric evaluation of root resorption on the upper incisors using cone beam computed tomography after 1 year of orthodontic treatment in adult patients with marginal bone loss

OBJECTIVES:

To determine upper incisor root resorption, volume loss, and the relationship between root volume loss and tooth movement after 1 year of orthodontic treatment in patients with marginal bone loss.

MATERIALS AND METHODS:

A total of 30 women (46.3 ± 5.4 years old) with moderate upper incisor bone loss who required intrusion during orthodontic treatment were recruited. Pre- and post-treatment cone beam computed tomography images were reconstructed. Upper incisors at pre- and post-treatment were superimposed; labio- and palato-apical, middle, and coronal third root volumes were assessed. Tooth movement and alveolar bone height were measured from lateral cephalometric radiographs and cone beam computed tomography. Changes in root volume/alveolar bone height were compared using paired-sample t-tests, percentage root volume loss for each tooth/segment was evaluated by one-way analysis of variance, and the relationship between percentage root loss and degree of tooth movement was assessed by linear regression.

RESULTS:

Mean root volume significantly decreased on the labio- and palato-apical aspects of 12 and labio-apical aspects of 21 and 22 ( P ≤ .024). Palato-apical segment volume loss was greater on lateral than central incisors ( P ≤ .016). Two-dimensional root length and cementoenamel junction-bone crest distance did not change between T0 and T1, with no significant relationship between tooth movement amount and percentage root volume loss.

CONCLUSIONS:

Delivery of 40 g intrusive force to the four upper incisors using a T-loop and the leveling phase lead to more apical root volume loss on lateral than central incisors. There was no relationship between extent of tooth movement and upper incisor root volume loss.

The effect of supragingival glycine air polishing on periodontitis during maintenance therapy: a randomized controlled trial

Background

Glycine air polishing has been proved to be safe, comfortable and time-saving. Whether it could substitute ultrasonic scaling to remove dental plaque biofilm during periodontal maintenance remains unclear. The purposes of this study were to evaluate the effect of supragingival glycine air polishing (SGAP) on the subgingival periodontal pathogens during maintenance therapy and to check the association of periodontal pathogens and clinical parameters.

Methods

Twenty-three chronic periodontitis patients during their maintenance therapy were enrolled in the 12-week study. According to randomized split-mouth design, the test side was treated with SGAP (65 μm), while the control side was treated with supragingival ultrasonic scaling and polishing (SUSP) with rubber cup. Clinical examination including plaque index (PLI), probing depth (PD), bleeding index (BI) were performed at baseline and 12 weeks post-treatment. Sampling of the subgingival plaque at each investigational site (mesiobuccal site of the mandibular first molar) was performed at baseline and 2, 4, 8, 12 weeks after maintenance treatment. Four periodontal pathogens including Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Fusobacterium nucleatum were detected by 16S rDNA polymerase chain reaction.

Results

Clinical status generally improved after treatment in both groups. PLI in both groups, PD in SGAP group and bleeding on probing (%) in SUSP group significantly decreased after treatment (p < 0.05). There was no significant difference of clinical parameters between two groups before and after treatment. The detection rates of P. gingivalis, T. denticola in both groups, T. forsythia in SUSP group and F. nucleatum in SGAP group decreased after maintenance treatment in both groups, although no significant difference was found, and it rebound to baseline level at 12 weeks after maintenance treatment. There was no significant difference between SGAP group and SUSP group at any time point. T. denticola-positive sites had significantly greater BI than T. denticola-negative sites (p < 0.05).

Discussion

Supragingival glycine air polishing had a reliable effect in removing subgingival dental plaque biofilm during maintenance period, and three months may be a proper maintenance interval for pockets not more than 5 mm.