Quintessence International, Pre-Print
DOI: 10.3290/j.qi.b3315007, PubMed ID (PMID): 35976749Pages 2-10, Language: English
Objective: The anterior loop, the mandibular incisive canal, and the lingual symphyseal foramen are important structures in the anterior mandible. The purpose of this study was to assess the prevalence of these structures using CBCT.
Method and materials: A total of 170 projections were analyzed in different sectional planes. The study analyzed the prevalence and extension of the anterior loop and the prevalence of both the mandibular incisive canal and the lingual symphyseal foramen by using the GALAXIS software by Sirona.
Results: In 98.2 % (n = 167) a lingual symphyseal foramen was detected. An anterior loop was present in 31.2% (n = 53) with statistically significant higher detection rate in younger patients (P = .001). The median length was 1.26 mm (range 0.53–3.70 mm). No statistically significant differences regarding patient side or sex were found in either case. In 72.4% (n = 123) a mandibular incisive canal was detected. There was a statistically significant dependence of the mandibular incisive canal on patient sex (P = .007): female patients had a mandibular incisive canal significantly more often than male patients. Among male patients a significant difference of the mandibular incisive canal regarding the mandibular side (P = .031) was found; it was significantly less frequent on the right than on the left side.
Conclusion: Anterior loop, mandibular incisive canal, and lingual symphyseal foramen are often present. Furthermore, the anatomical, neurovascular variability in the interforaminal area of the mandible emphasizes the importance of 3D imaging like CBCT in preoperative assessment, and confirms that a general safe zone should not solely be relied upon when performing surgery in this region.
Keywords: anterior loop, CBCT, interforaminal mandible, lingual foramen, mandibular incisive canal
Oral Health and Preventive Dentistry, 1/2022
Open Access Online OnlyOral MedicineDOI: 10.3290/j.ohpd.b2395059, PubMed ID (PMID): 35049248Pages 11-17, Language: English
Purpose: To evaluate the use of hydrogen peroxide as an adjunct to ultrasonication (US) in biofilm removal and whether it can limit the spread of viable microorganisms in the aerosol.
Materials and Methods: Multi-species biofilms were formed on dentin disks and titanium disks fixed on a plastic surface. After placing the specimens in a periodontal pocket model, an ultrasonic scaler was applied for 30 s, in part combined with 0.25% or 0.5% H2O2. After treatment, the remaining biofilm was analysed for bacterial counts (colony forming units [CFU]), biofilm quantity and metabolic activity. Further, the cytotoxic effect of hydrogen peroxide on periodontal ligament fibroblasts was assessed and the spread of bacteria in aerosol was quantified.
Results: Ultrasonication reduced bacterial counts in biofilm, biofilm mass and metabolic activity on both dentin and titanium disks. Adjunctive use of 0.25% and 0.5% H2O2 more effectively reduced the viable bacteria in biofilm than ultrasonication alone; this was also found on both dentin and titanium. The different concentrations of H2O2 did not lead to corresponding differences in bacterial mass and metabolic activity. The spread of bacteria through aerosols was statistically significantly reduced when adjunctive H2O2 was used. However, a certain cytotoxic effect on periodontal ligament fibroblasts by H2O2 could not be ruled out.
Conclusions: Irrigating with H2O2 during periodontal instrumentation with an ultrasonic scaler increases the reduction of viable bacteria within biofilms. It might limit bacterial spreading via aerosols.
Keywords: aerosol, biofilm, hydrogen peroxide, periodontal therapy
Oral Health and Preventive Dentistry, 1/2022
Open Access Online OnlyPeriodontologyDOI: 10.3290/j.ohpd.b2805491, PubMed ID (PMID): 35285602Pages 133-140, Language: English
Purpose: Regenerative periodontal therapy using platelet-rich plasma (PRP) and bone substitutes with guided tissue regeneration (GTR) have been proposed as a therapeutic method to enhance the outcome of regenerative surgery. This includes light microscopic evaluation of retrieved ePTFE membranes to assess formation of new connective tissue attachment, and following the regeneration process. The objectives of this study were to evaluate the histological findings of retrieved ePTFE membranes using PRP and bone substitutes, the effect of PRP on graft materials, and the correlation of the findings with the clinical outcomes.
Materials and Methods: Seventy-two (72) patients with chronic periodontitis, each of whom had one deep intrabony defect, were randomly included in two studies and treated using the same type of membrane and different bone substitutes. In the first study, 17 cases were treated with a natural bone mineral and a non-resorbable membrane (NBM + GTR), and 17 cases were treated with PRP + NBM + GTR. In the second study, 19 patients were treated with β-tricalcium phosphate and a non-resorbable membrane (β-TCP + GTR), and 19 patients were treated with PRP + β-TCP + GTR. In both studies, tissue integration of the retrieved ePTFE membranes and attached remnants were evaluated histologically.
Results: Histological scores showed that membranes combined with NBM are better integrated than membranes combined with β-TCP; the difference between the two decreased with the addition of PRP. The application of PRP had no significant effect on the quality of membrane integration combined with NBM, whilst significantly improving the integration quality when combined with β-TCP. No correlations were detected between the histological scores and the clinical attachment level (CAL) gain in any of the groups.
Conclusions: The present results indicate that: a) application of β-TCP and PRP may enhance membrane integration and periodontal healing, and b) histological examination of retrieved membranes may provide valuable additional information with regard to the clinical findings.
Keywords: β-tricalcium phosphate, guided tissue regeneration, histological evaluation, natural bone mineral, platelet-rich plasma
Quintessence International, 7/2021
DOI: 10.3290/j.qi.b1098307, PubMed ID (PMID): 33749221Pages 576-582, Language: English
Objectives: To describe the step-by-step procedure of a novel surgical technique consisting of a combination of the laterally closed tunnel (LCT) and the modified coronally advanced tunnel (MCAT) (ie, LCT/MCAT), designed to treat multiple mandibular adjacent gingival recessions (MAGR) and to present the clinical outcomes obtained in 11 consecutively treated patients.
Method and materials: Eleven systemically and periodontally healthy patients (7 females, mean ± SD 33.62 ± 14.6 years, min. 19 years max. 67 years) with a total of 40 adjacent mandibular RT1 (ie, Miller Class 1 and 2) gingival recessions with a minimum depth ≥ 3 mm, were consecutively treated with LCT/MCAT, in conjunction with an enamel matrix derivative (EMD) and subepithelial palatal connective tissue graft (SCTG). Treatment outcomes were assessed at baseline and at 12 months postoperatively. Prior to surgery and at 12 months postoperatively, recession depth (RD) and recession width (RW) were evaluated. The primary outcome variable was complete root coverage (CRC, ie 100% root coverage), the secondary outcome was mean root coverage (MRC).
Results: Postoperative pain and discomfort were low and the healing was uneventful in all cases without any complications. At 12 months, statistically significant (P < .05) root coverage (RC) was obtained in all patients. CRC was obtained in five patients with a total of 21 recessions, while MRC measured 92.9% (ie, 3.75 mm). In seven patients (ie, 63.6%), RC amounted to > 93% while the minimum RC per patient measured 83.76%.
Conclusion: The results of the present case series suggest that the LCT/MCAT is a valuable technique for the treatment of mandibular RT1 MAGR.
Keywords: laterally closed tunnel, modified coronally advanced tunnel, multiple adjacent mandibular gingival recessions, recession coverage, subepithelial palatal connective tissue graft, surgical technique
International Journal of Periodontics & Restorative Dentistry, 6/2021
DOI: 10.11607/prd.5774Pages 811-817, Language: English
Certain bone morphologies and soft tissue thickness (ie, phenotype) are considered to be risk factors for the development of gingival recessions following orthodontic tooth movement. Preoperative evaluation of the periodontal phenotype, in the frame of orthodontic treatment plan, identify teeth at high risk for mucogingival complications related to orthodontic therapy. The new surgical technique is illustrated in a clinical case. A patient with a thin phenotype without visible gingival recession had bone dehiscences in the anterior mandible. Prior to orthodontic treatment, simultaneous bone and soft tissue augmentation was performed using the combination of a highly cross-linked ribose porcine type I collagen membrane and a subepithelial palatal connective tissue graft. Two years after augmentation surgery and initiation of orthodontic treatment, a thick buccal tissue with a wide band of attached gingiva was observed without any clinical signs of root prominences, indicating a substantial change in periodontal phenotype. The clinical findings were corroborated by the 3D analysis, demonstrating substantial bone apposition on the buccal aspect of all roots in the treated area. The described surgical technique offers a valuable approach for regenerating hard and soft tissues in deficient areas prior to orthodontic therapy, thus preventing the development of gingival recessions.
Quintessence International, 5/2021
DOI: 10.3290/j.qi.b937015, PubMed ID (PMID): 33533238Pages 394-401, Language: English
Objective: Transgingival probing is often used in the clinic to assess gingival thickness. However, what is not completely known is how well this method represents the true value of soft tissue thickness. The aim of this study was to assess differences and variation in gingival thickness when measured with transgingival probing or scanned with an intraoral device. Method and materials: This ex vivo study evaluated gingival thickness on 20 porcine cadavers. Gingival thickness was assessed at both central and lateral mandibular incisors through transgingival probing with a standard metal periodontal probe and also using intraoral scanning, which was considered as the method providing the ‘true value’ of soft tissue thickness. Intra-examiner repeatability and method error were evaluated.
Results: No evidence of systematic difference for any of the mandibular central or lateral incisors (mandibular right incisors: mean difference −0.17 to −0.01 mm, and mandibular left incisors: mean difference −0.11 to 0.04 mm) was observed between the periodontal probe and intraoral scanning methods. The absolute differences between the repeated measurements with intraoral scanning for each tooth type (n = 30) were calculated: the overall median was 0.089 mm and the interquartile range was 0.080 mm.
Conclusions: Transgingival probing with a standard metal periodontal probe for assessing gingival thickness is a reliable method, with values very close to the true gingival thickness, and it can thus be considered as the clinical gold standard.
Keywords: periodontal, scan, tooth anatomy
Quintessence International, 4/2021
DOI: 10.3290/j.qi.b937003, PubMed ID (PMID): 33533237Pages 308-316, Language: English
Objectives: In-vitro data have shown that cross-linked hyaluronic acid (HA) enhances the proliferative and migratory properties of cells involved in periodontal wound healing/regeneration, stabilizes the blood clot, reduces the inflammatory response, and facilitates angiogenesis. The aim of this study was to histologically evaluate the effects of cross-linked HA alone or combined with a collagen matrix (CM) on the periodontal wound healing/regeneration in intrabony defects. Method and materials: Two-wall intrabony defects (5 mm wide, 5 mm deep) were surgically created at the distal and mesial aspects of mandibular premolars in six beagle dogs. The 24 defects were randomly treated as follows: open flap debridement (OFD) + HA, OFD + CM, OFD + HA + CM (HA/CM), and OFD alone (control). At 2 months, the animals were euthanized for histologic evaluation.
Results: The HA (2.43 ± 1.25 mm) and HA/CM (2.60 ± 0.99 mm) groups yielded statistically significantly (P < .05) greater formation of new attachment (ie, linear length of new cementum adjacent to newly formed bone, with inserting collagen fibers) compared with the OFD (0.55 ± 0.99 mm) group. Among the four treatment groups, the HA/CM group demonstrated the highest amount of regenerated tissues, although no statistically significant differences in any of the histometric parameters were observed between the HA and HA/CM groups.
Conclusion: Within their limits, it can be concluded that cross-linked HA alone or combined with CM promotes periodontal wound healing/regeneration in two-wall intrabony defects in dogs.
Keywords: animal study, biomaterials, hyaluronic acid, intrabony defect, periodontal wound healing/regeneration
International Journal of Periodontics & Restorative Dentistry, 4/2021
Pages 539-545, Language: English
Bone exostosis is defined as a benign overgrowth of bone tissue of unclear origin. Rarely, bone exostosis might develop following soft tissue graft procedures like mucogingival surgical interventions (eg, FGG or subepithelial CTG). This aberration has been mainly associated with surgical trauma or fenestration of the periosteum but is still a matter of debate. The present paper (1) presents a clinical case with clinical, radiographic, and histologic findings at 30 years following application of an FGG to increase the gingival width and (2) provides a short literature review on this particular clinical condition. At the clinical examination, the FGG was firm to palpation, and the 3D images showed an area of increased radiopacity. Histologic analysis revealed localized thickening of the bone with an overlaying connective tissue covered by keratinized epithelium. The bony tissue was vital, had a convex shape, and contained many osteocytes and resting lines, demonstrating some moderate signs of bone remodeling. The connective tissue and keratinized epithelium displayed a regular thickness without any signs of inflammation. Taken together, the histologic findings failed to reveal any pathologic signs except for the presence of vital bone formed outside the bony envelope. It can be concluded that: (1) the development of a bone exostosis following a mucogingival procedure is a rare clinical sequela of uncertain etiology, and (2) surgical removal of the exostosis may be indicated accordingly with patient symptoms.
Pages 161-169, Language: German
Seit ihrer Entwicklung und Einführung vor ca. 25 Jahren haben sich die Schmelz-Matrix-Proteine (SMP) als ein Standardmaterial in der regenerativen Parondontaltherapie etabliert. Ergebnisse aus In-vitro-Experimenten, Tierstudien und randomisierten klinischen Studien haben die Evidenz geliefert, dass die Anwendung der SMPs im Rahmen der chirurgischen Therapie die parodontale Wundheilung und Regeneration in intraossären Defekten, Grad-II-Furkationsbefall, aber auch in Rezessionsdefekten fördert und dabei die klinischen Ergebnisse signifikant verbessert. Neueste Daten konnten sogar den Hinweis liefern, dass die SMPs die Ergebnisse der chirurgischen Therapie in supraalveolären Defekten und der nichtchirurgischen Therapie verbessern können und somit eine Erweiterung der klinischen Anwendungen ermöglichen. Ziel der vorliegenden Arbeit ist es, basierend auf der vorhandenen Evidenz die klinischen Indikationen für die Anwendung der Schmelz-Matrix-Proteine darzustellen. Trotz aller positiven Eigenschaften müssen SMPs dennoch streng indikationsbezogen und vor allem bei der Therapie von vertikalen Defekten, Grad-II-Furkationsbefall und Rezessionen im Rahmen eines Gesamtkonzepts gesehen werden. Die Anwendungen im Rahmen der chirurgischen Therapie von supraaveolären Defekten, der nichtchirurgischen Therapie oder in Kombinationen mit Bindegewebetransplantaten für die Rezessionsdeckung sollten kritisch und fallbezogen erwogen werden.
Manuskripteingang: 23.12.2020, Annahme: 25.04.2021
Keywords: Schmelz-Matrix-Proteine, parodontale Regeneration, chirurgische Parodontaltherapie, nichtchirurgische Parodontaltherapie, intraossäre Defekte, Furkationsdefekte, Rezessionsdeckung
Quintessence International, 10/2021
DOI: 10.3290/j.qi.b1702285, PubMed ID (PMID): 34235909Pages 848-861, Language: English
Objective: To evaluate the clinical outcomes 2 years after the adjunctive use of an InGaAsP diode and Er,Cr:YSGG laser for nonsurgical treatment of severe periodontitis.
Method and materials: Forty-two patients (45.31 ± 9.78 years old, n = 22 females, n = 23 smokers) with stage III or IV grade B periodontitis were randomly treated either with laser (InGaAsP + Er,Cr:YSGG) adjunctive to subgingival debridement (test group, n = 21) or with subgingival debridement alone (control group, n = 21). Subjects in the test group received a second laser treatment in residual sites 2 months after the initial laser therapy. At baseline, and at 12 and 24 months after therapy, periodontal clinical parameters were evaluated. The primary outcome variable was the number of residual deep sites at 12 months (probing depth [PD] ≥ 6 mm).
Results: One and two years after nonsurgical periodontal treatment, both groups yielded statistically significant clinical improvements. The adjunctive use of InGaAsP and Er,Cr:YSGG laser to mechanical debridement resulted in statistically significantly higher clinical (PD, clinical attachment level, bleeding on probing, number of sites with PD ≥ 5 mm, PD ≥ 6 mm, PD ≥ 7 mm) improvements (P < .05) compared to subgingival debridement alone both at 12 and 24 months after therapy.
Conclusion: In patients with stage III or IV grade B periodontitis, InGaAsP and Er,Cr:YSGG used adjunctively to subgingival debridement may additionally improve the clinical outcomes compared to mechanical debridement alone over a period of 24 months.
Keywords: YSGG, InGaAsP, periodontal laser therapy, periodontal treatment, periodontitis