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Background: To investigate tooth‐related factors that influence the reduction of probing pocket depths (PPD) after non‐surgical periodontal therapy (NST). Methods: Seven hundred forty‐six patients with a total of 16,825 teeth were included and retrospectively analyzed. PPD reduction after NST was correlated with the tooth‐related factors; tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration; using logistic multilevel regression for statistical analysis. Results: NST was able to reduce probing depth overall stratified probing depths (1.20 ± 1.51 mm, p ≤ 0.001). The reduction was significantly higher at teeth with higher probing depths at baseline. At pockets with PPD ≥ 6 mm, PPD remains high after NST. Tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration are significantly and independently associated with the rate of pocket closure. Conclusions: The tooth‐related factors: tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration had a significant and clinically relevant influence on phase I and II therapy. Considering these factors in advance may enhance the prediction of sites not responding adequately and the potential need for additional treatment, such as re‐instrumentation or periodontal surgery, to ultimately achieve the therapy end points. [ABSTRACT FROM AUTHOR]

Three-dimensional printing has introduced new manufacturing methods. However, information on the influence of the specific printing technology, material, sterilization, and the comparison between printing and milling on the accuracy of surgical guides is lacking. The purpose of this in vitro study was to evaluate the influence of the manufacturing method (printing and milling), printing technology stereolithography (SLA) and digital light processing (DLP), material, and sterilization on the accuracy of digitally designed surgical implant guides. Resin patient replicas with a single edentulous space were used to place 132 implants with digitally designed surgical guides. The accuracy of postoperative implant position was analyzed for the manufacturing method (printing and milling), resin materials, and preoperative autoclaving. To determine 3D accuracy, angular displacement, mean horizontal crestal, apical displacement, and the linear vertical displacement at the apex were calculated separately for each group (n=12). In addition, the surgical guides were qualitatively analyzed by using field emission scanning electron micrograph. The postoperative angular deviation ranged from 0.76 ±0.52 degrees (Rapidshape D20II with NextDent SG) to 2.43 ±0.64 degrees (Form2 with NextDent SG) (P <.001). Linear horizontal displacement at the crest was smallest for Rapidshape D20II with 3Delta Guide (0.27 ±0.08 mm) and highest for Form2 with NextDent SG (0.54 ±0.10 mm) (P <.001). Linear horizontal displacement at the apex ranged from 0.36 ±0.10 mm (SolFlex 350 with V-Print SG) to 0.89 ±0.32 mm (Form2 with NextDent SG) (P <.001). Considering the vertical position displacement was no more than 0.43 ±0.07 mm (Form2 with NextDent SG) short of the apex, none of the implant tips were displaced apically. Preoperative autoclaving differentially impaired the accuracy of surgical guides. The specific manufacturing technique, the 3D printing device, the resin material, and the application of preoperative sterilization all affected the accuracy of the postoperative implant position. Irrespective of the manufacturing method, all implants were placed within the commonly accepted safety distance. [ABSTRACT FROM AUTHOR]

Regenerative therapies of pathogenic tissue defects are gaining increasing importance in periodontology. Among others, the osteogenic effect of BMP-7 seems to play a major role in the development of teeth and alveolar bone. Human periodontal ligament stem cells (hPDLSC), as well as human mesenchymal stem cells (hMSC), show the ability to differentiate into various types of tissues. Regarding prostaglandin E2, many studies have confirmed that it is involved in the inflammation associated to periodontitis stimulating osteoclasts, which ultimately leads to resorption of tooth supporting bone. Herein, we aimed to investigate how PGE2 influences regenerative processes. The influence of PGE2 and BMP-7 on the osteogenic differentiation of hMSC and hPDLSC was determined in a 3D cell culture model using qRT-PCR, immunocytochemistry and REM. BMP-7 enhanced the expression of osteogenic markers in hMSC and lowered it in hPDLSC-TERT. BMP-7 had a lower osteogenic effect on hPDLSC-hTERT than on hMSC, while PGE2 decreases the osteogenic differentiation in both cell types, thus, inhibiting anabolic processes. Both cell types presented good proliferation and adhesion onto the scaffolds. The well-developed structural morphology and the support of osteogenic differentiation suggest that the scaffolds are potential candidate materials for bone regeneration. The positivity for Cap in hPDLSC and more in hMSC immunostaining samples indicates the initiation of neocementogenesis as part of periodontal regeneration. In conclusion, BMP7, in particular combined with MSC, seems to have a favourable application also in periodontal regeneration. Our results show that inflammation plays an important role in periodontal regeneration. PGE2 is a key mediator, which stimulates bone resorption also via a mechanism involving the inhibition of osteogenic differentiation of MSC as well as PDLSC. Therefore, regenerative approaches should always be conducted in combination with anti-inflammatory measures oriented to control inflammation. [ABSTRACT FROM AUTHOR]

Objective: To compare the severity of clinical inflammation parameters and the level of the inflammatory mediator interleukin (IL)-1β during orthodontic treatment by using brackets and bands. In addition, the effect of a chlorhexidine-containing varnish was investigated. Materials and Methods: This prospective randomized controlled trial included 40 healthy children who required an orthodontic treatment of mild crowding. Either brackets or bands were randomly allocated to the premolars with a split-mouth design. Twenty of the children received a chlorhexidine-containing varnish during the treatment (0, 12, 24 weeks), while the remaining children served as a control group. Prior and until 24 weeks after the insertion, data were recorded regarding the pocket depth (PD), the gingival appearance (gingival index [GI]), and the plaque accumulation (plaque index [PI]). Gingival crevicular fluid was collected as well. A quantitative enzyme-linked immunoassay technique was used to detect differences in IL-1β. Results: The PDs and the gingival index of teeth with brackets showed significantly lower values in comparison with teeth treated with bands (P = .0001). The IL-1β levels confirmed these findings. In contrast, the PI showed higher values for the teeth with brackets (P = .0001). The teeth that received a chlorhexidine-containing varnish showed significantly lower values in the follow-ups for most of the evaluated parameters (PDBand, PIBand, PIBracket, GIBand, GIBracket; P < .015). Conclusion: The clinically observed parameters as well as the IL-1β levels reflected the higher impact of bands on gingival health. These values showed a significant decrease after application of a chlorhexidine-containing varnish. However, the PI showed higher values for the teeth with brackets. [ABSTRACT FROM AUTHOR]

Background: This in vitro study aimed to evaluate the influence of different parameters, i.e., lateral force, instrument power setting, and the shape of the working tip, on the roughness of root surfaces following treatment with a magnetostrictive ultrasonic scaling device. I Methods: The study sample comprised a total of 102 extracted human molars, premolars, canines, and incisors. The samples were randomly divided into 10 equal units of 10 each for treatment with the ultrasonic device at a lateral force of 0.5 N and 2.0 N, a low and high instrument power setting, and with a straight and angulated shaped working tip. Twenty samples were treated manually using curets at a lateral force of 0.5 N and 2.0 N. Two samples were left untreated as controls. The mean (Ra) and maximum (RMAX) surface roughness of each sample was recorded. The statistical analysis was performed using analysis of variance (three-way ANOVA) at a level of significance of 5% (P <0.05). Results: The mean surface roughness (±SD) using different parameters ranged from 0.6 ± 0.1 µm to 1.8 ± 0.3 µm. The maximum surface roughness (±SD) was between 4.8 ± 1.3 µm and 17.2 ± 4.3 µm. The mean surface roughness (±SD) for samples treated with curets at a lateral force of 0.5 N was 0.5 ± 0.0 µm and 0.4 ± 0.1 um at 2.0 N. The maximum surface roughness (±SD) was 3.7 ± 0.8 µm at 0.5 N and 3.9 ± 1.4 µm at 2.0 N. Conclusions: The findings of the present study indicate that the shape of the working tip and the lateral force significantly influence the mean and maximum surface roughness of root surfaces treated with a magnetostrictive ultrasonic scaling device. At any specific parameter, the surface roughness was significantly higher for the ultrasonic scaling device as compared to the hand curet. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to compare the ability of the diode laser to detect residual calculus with that of an explorer. Methods: The root surface of 40 extracted human teeth, each partially covered with subgingival calculus, was instrumented with curets under simulated clinical conditions in a manikin. The samples were randomly assigned to two study groups. In group A, the root surface was treated with an explorer until it appeared free of mineralized deposits upon examination. The samples in group B were instrumented until the relative intensity of fluorescence as induced with diode laser radiation was below a threshold value of 5. The root surface of each sample was then examined for residual calculus using standardized digital images. The statistical analysis was performed with a non-paired t test at a level of significance of 5% (P<0.05). Results: The root surface of single-rooted teeth showed residual calculus on 0.19±0.37 x 107 µm² in the laser group and on 0.11±0.26xl07 µm² in the explorer group (P=0.19). For multi-rooted teeth, the mean calculus-covered area was 0.50±0.48 x 107 µm² for the teeth evaluated with an explorer and 0.27±0.43 x 107 µm² for the diode laser group (P=0.02). Conclusion: The present findings indicate that the detection of subgingival calculus is significantly improved using 655 nm diode laser radiation compared to an explorer for molars but not for single-rooted teeth. [ABSTRACT FROM AUTHOR]

Background: Previous scanning electron microscopy (SEM) studies using extracted teeth have shown the potential of infrared Er:YAG laser radiation to remove subgingival calculus without causing severe thermal changes, e.g., charring or fusion, to the irradiated root surface. The purpose of the present study was to examine the morphologic changes on root surfaces following Er:YAG laser irradiation in situ using histological observation. Methods: The periodontal pockets of 6 premolars, canines, and incisors that remained in situ in the jaws of human corpses were irradiated with Er:YAG laser radiation at 60 mJ, 100 mJ, or 180 mJ. The pockets were treated in a similar manner to normal clinical circumstances with a total amount of either 50 or 100 laser pulses. Following laser treatment, the entire tooth, marginal gingiva, and underlying alveolar bone were removed from the jaw. The sections were embedded in methyl-methacrylate, serially cross-sectioned, stained with hematoxylin and eosin or gallamine blue, and examined under a light microscope. Additionally, the extension of the thermally changed tissue areas was determined using digital images and histometry. Results: The historical examination revealed two kinds of thermal changes within the laser-treated root surface. Firstly, a thin superficial layer 5 to 10 µm in width was observed. The surface of this layer showed ultra structural irregularities. Secondly, a semicircular more deeply stained area close to the apical end of the scaling track beneath the irradiated cementum was observed. The depth of this area ranged from 255 µm to 611 Jim and appeared to be independent of the radiation energy. Conclusion: In contrast to previous SEM studies, the histological examination indicated thermal changes within the hard tissue bordering the periodontal pocket following Er:YAG laser irradiation. [ABSTRACT FROM AUTHOR]

Background: It has been suggested that the 655 nm InGaAsP diode laser radiation can induce considerably higher amounts of fluorescence in subgingival calculus than in cementum. This in vitro study evaluated the use of fluorescence induced by the diode laser radiation for the detection of subgingival calculus. Methods: The study sample consisted of 30 extracted molars, Premolars, canines, and incisors. The root surface of each sample was partially covered with subgingival calculus. The source of laser radiation was an InGaAsP diode laser emitting visible radiation at a wavelength of 655 nm. The fluorescent radiation reflected from the cementum and calculus was detected by a photoelectric cell integrated within the diagnostic system. The samples were randomly assigned to 3 experimental groups of 10 teeth each for detection of calculus in various media. Specifically, the fluorescence was determined in air (group A), in electrolytic salt solution (group B), and in blood (group C). For each sample, the intensity of the fluorescent light was evaluated separately for cementum and calculus in triplicate measurements. The statistical analysis was performed using a t test at a level of significance of 5% (P <0.05). Results: The intensities of fluorescence radiation emitted by cementum were 0.4 (±0.51) in air, 0.4 (±0.51) in electrolytic solution, and 2.13 (±0.59) in blood. For calculus, the relative intensities of fluorescence radiation were 54.1 (±29.09) in air, 60.77 (±28.35) in electrolytic salt solution, and 39.63 (±29.79) in blood. The differences in fluorescence between cementum and calculus within each experimental unit were significant (group A: P= 0.0002, group B: P= 0.0001, group C: P= 0.031). The intensity of fluorescence in calculus was also significantly different between the 3 experimental groups. Conclusion: The present study indicates that subgingival calculus can be reliably detected on extracted teeth using laser fluorescence induced by the 655 nm diode-laser radiation. In vivo studies are necessary to evaluate the clinical utility of this procedure. [ABSTRACT FROM AUTHOR]

The in vitro study aimed at the determination of the bacterial reduction in root canals used pulsed Nd:YAG laser radiation without a photosensitizing dye. In addition the temperature change in the root canals was determined during laser irradiation. The study sample was 114 root canals of extracted single-rooted human teeth that have been enlarged mechanically, sterilized, and randomly assigned to two experimental units. The source of radiation was a Nd:YAG laser device emitting pulsed infrared radiation at a wavelength of 1.064 μm, a pulse duration of 100 μs, and a pulse repetition rate of 20 pps. Samples of each experimental unit were inoculated with Escherichia coli (ATCC 25922) or Staphylococcus aureus (ATCC 25923), respectively, and divided into subgroups of 13 teeth each for irradiation for 20 s at 100 mJ or 200 mJ. One subgroup was left untreated as positive control and one subgroup was rinsed with 0.5 ml of sodium hypochloride. After laser treatment or rinsing with sodium hypochloride the number of bacteria in each root canal was determined using the surface spread plate technique. Statistical analysis of the results was performed with ANOVA and Scheffé test at a level of significance of 5% (p < 0.05). In case of E. coli the number of bacteria was reduced from 8.67 · 106 (±4.11 · 105) colony-forming units (CFU)/ml to 4.39 · 104 (±1.72 · 104) CFU/ml after laser radiation at 200 mJ. Regarding S. aureus the number of bacteria decreased from 1.44 · 106 (±1.59 · 105) CFU/ml to 3.8 · 104 (±1.06 · 104) CFU/ml at a radiation energy of 200 mJ. Rinsing with sodium hypochloride reduced the number of bacteria to 1.03 · 103 (±4.02 · 102) CFU/ml regarding E. coli and to 1.84 · 103 (±7.4 · 102) CFU/ml in case of S. aureus. The temperature increase at 100 mJ was 24.3°C (±3.9) and that at 200 mJ was 61.8°C (±4.2). The Nd:YAG laser radiation has antimicrobial effects in root canals even in the absence of photosensitizing dyes but also causes considerable temperature increase. [Copyright &y& Elsevier]

Purpose; To evaluate the 5-yr clinical performance of a resin-modified glass-ionomer cement and a poly-acid-modified resin composite in restoring non-carious cervical lesions. Materials and methods: Non-carious cervical lesions in 46 incisors, canines, and premolars were restored either with Fuji II LC (n=18) or with Dyract (n=28) in 16 healthy patients. The lesions were restored without cavity preparation strictly according to the manufacturer's instructions. The restorations were clinically evaluated single blind after 5 yrs using modified USPHS criteria Results: The percentage of Alfa ratings were as follows (Dyract/Fuji II LC): color match 81.3%/28.6%, surface texture 93.8%21.4%, anatomic form 75.0%/28.6%, marginal integrity (enamel) 62.5%/42.9%, marginal integrity (dentin) 68.80%/28.6%, marginal discoloration (enamel) 56.3%/42.9%, marginal discoloration (dentin) 68.8%/21.5%. Five-yr data revealed a significant difference between the clinical ratings of Dyract and Fuji II LC for all criteria except marginal integrity and marginal discoloration in enamel. A total of five Dyract restorations and four Fuji II LC restorations failed within the study period. [ABSTRACT FROM AUTHOR]

Background: The recently introduced Er:YAG laser radiation appears to be a promising alternative in treating dental hard tissue due to its thermo-mechanical ablation properties and the lack of thermal side effects. The present in vitro study attempted to evaluate the use of Er:YAG laser radiation in combination with a specially developed delivery system in removing calculus from root surfaces. Methods: Fifty extracted anterior teeth, premolars and molars, were divided into 2 groups of 25 each with (group A) and without (group B) subgingival calculus. Source of radiation was an Er:YAG laser device with a wavelength of 2.94 µm, in the infrared optical spectrum, a pulse duration of 250 ns, and a pulse repetition rate of 15 pps. In each group, 6 teeth were irradiated with 300 laser pulses either at 60 mJ, 30 mJ, 100 mJ, or 150 mJ. The samples were continually moved linearily using a computer numeric controlled device. The volumetric evaluation of root substance removal was performed with a 3-dimensional laser scanning system (100.000 surface points per sample, accuracy: 5 µm) and special image analyzing software. A scanning electron microscopic (SEM) observation was performed to assess the laser induced ultra structural changes on the root surfaces. Statistical analysis was carried out with ANOVA followed by the Scheffé test and with regression analysis according to Pearson-Bravais at a level of significance of 5% (P <0.05). Results: The linear measurement of substance removal on calculus samples (group A) revealed average depths between 174.33 (±16.13) µm and 501.85 (±111.01) µm. Defect depths on the teeth without calculus (group B) ranged from 37.78 (±14.03) µm to 484.44 (±80.63) µm. The SEM observation of laser-treated root surfaces revealed no signs of thermal damage; e g., melting, fusion, or cracking. Conclusions: The results of the present study showed that a substance removal with Er:YAG laser radiation at lower energy densities is comparable, in effect, to that after conventional root surface instrumentation with curets. The results seem to indicate that calculus removal can be selectively done using lower radiation energies. Considering the favorable results of the SEM investigation, the use of the Er:YAG laser in periodontal therapy may be possible in the future. [ABSTRACT FROM AUTHOR]

Purpose: To determine the potential of 2.94 µm Er:YAG laser radiation in remove bacterial endotoxin from root surfaces. Materials and Methods: 40 extracted teeth were divided into four groups of 10 samples each A 16 mm² area of the root surface on each sample was inoculated with an aliquot of 7 µl of a lipopolysaccharide suspension at a conc entration of 50 IU/ml. LPS was derived from a non-oral Escherichia coli strain (E. coli 055:B5). Source of laser radiation was an Er:YAG laser emitting pulsed infrared radiation at a wavelength of 2.94 µm, with a pulse duration of 250 µs, and a pulse; repetition rate of 15 pps. Three specimen groups were irradiated with 105 laser pulses at a radiation energy of 60mJ, 100mJ and 140 mJ. One specimen group was untreated (control). The LPS concentration with each sample was determined using a ch romogenic, quantitative Limulus-amoebocyte-lysate assay. Statistical analysis was ANOVA and Scheffé-test. Results: Mean LPS yield from the untreated control samples was 50.1 (± 35.9) IU/ml. Following laser irradiation the average LPS on the root surfaces was 19.86(± 14.4) IU/ml at 60 mJ, 12.86 (± 8.1) IU/ml at 100mJ and 8.58 (± 4.9) IU/ml at 140 mJ. [ABSTRACT FROM AUTHOR]

The article presents a case study of a young patient with a rapidly progressive caries, severe periodontitis and gingivitis who was sent to the dentistry. It states that he had undergone a radiotherapy in his young age. He was provided with an effective treatment plan where his two molars were removed and periodontal with endodontic treatment was also performed. The article discusses the relationship of dental and skeletal developmental disturbances resulting from radiotherapy.