The topography of the furcation entrance in Chinese molars. Furcation entrance dimensions

Clinical Benefits of Minimally Invasive Non-Surgical Periodontal Therapy as an Alternative of Conventional Non-Surgical Periodontal Therapy-A Pilot Study

Minimally invasive procedures were introduced in periodontics, which could enhance clinical outcomes and reduce post-operative discomfort. However, minimally invasive non-surgical periodontal therapy (MINST) as an alternative modality of conventional non-surgical root surface debridement has not been clearly evaluated by randomized controlled clinical trial. The present study aimed to investigate clinical outcomes and patients’ comfort feedback of MINST compared to conventional non-surgical periodontal therapy (CNST). Patients with moderate to severe periodontitis were included. Nine out of ten patients were recruited and completed the post-treatment re-evaluation in this study. Randomized split-mouth design, CNST and MINST on each side, was performed. Clinical parameters, including periodontal probing depth (PD), gingival recession (REC), clinical attachment level (CAL), and gingival bleeding on probing (BOP), were recorded on baseline, 1 month and 3 months post-treatment. Non-parametric statistics were used for analysis. PD, REC, CAL, and BOP were improved after treatment in both CNST and MINST groups. Comfort feedback and gingival recession showed better outcomes in the MINST group than in the CNST group. No statistical significance of parameters was found between CNST and MINST. Within the limitations, minimally invasive non-surgical periodontal therapy could be an alternative modality of conventional non-surgical periodontal therapy. Further studies are required to establish clinical protocol and evidence of MINST.

Results of an experimental study of subgingival cleaning effectiveness in the furcation area

BACKGROUND

Sufficient biofilm removal in the furcation area (FA) is a major challenge in the clinical practice of supportive periodontal therapy. The aim of the present experimental study was to simulate subgingival cleaning of the FA using a powered scaler (sonic scaler (AIR), ultrasonic scaler (US)) for conventional mechanical debridement versus two air polishing with nonabrasive powder (LAPA-1: glycine powder, LAPA-2: erythritol powder) and different nozzles for supra-/subgingival cleaning for each device.

METHODS

Seven trained and calibrated operators with ≥ 2 years each of professional experience in treating periodontitis used the instruments to clean 3D-printed replicas of six molars with through-and-through FA (four 3-rooted and two 2-rooted teeth) in a manikin head. AIR and US were used in the control group; air polishing instruments were used in the test group. For reproducible evaluation, the test teeth were separated vertically into two or three parts, illuminated with ultraviolet light, photographed and evaluated planimetrically. Treatment time (TrT, in s) and relative cleaning efficacy (RCE, in %) were measured.

RESULTS

Overall, 3-rooted molars (RCE in the entire FA, 23.19 ± 20.98%) could be cleaned significantly less effectively than 2-rooted molars (53.04 ± 28.45%, p < 0.001), regardless of the instrument used. In the cleaning of the entire FA, significantly higher RCE values were achieved with conventional mechanical debridement (AIR/US: 46.04 ± 25.96%/39.63 ± 22.02%; AIR vs. US: p > 0.05) than with air polishing (LAPA-1/LAPA-2: 34.06 ± 29.48%/17.09 ± 18.85%; LAPA-1 vs. LAPA-2: p < 0.001) regardless of whether a supra- or subgingival cleaning nozzle used (p < 0.001). Only LAPA-1 with a subgingival nozzle showed RCE values comparable to those of US (41.07 ± 28.95% vs. 39.63 ± 22.02%, p > 0.05). TrT was longest for US (299.40 ± 120.69 s) and shortest for LAPA-1 with a supragingival nozzle (129.67 ± 60.92 s, p < 0.001).

CONCLUSIONS

All of the examined instruments were effective to some degree in removing the simulated biofilm from the FA, but they differed substantially in cleaning efficacy. Only one air polishing device (LAPA-1) with a rigid subgingival nozzle was able to achieve RCE values similar to those of US. The current investigation confirmed that conventional mechanical debridement with powered scalers were most effective, but treatment took longer with these devices than air polishing.

Prevalence and morphological characteristics of disto-lingual roots in mandibular first molars: a cone beam CT study with diagnostic and therapeutic implications

OBJECTIVES

High prevalence of disto-lingual roots (DLR) at the mandibular molar in Chinese can complicate the management of periodontitis. This study assessed the prevalence and morphological features of mandibular first molar DLR and furcation entrances in a Hong Kong population by analysis of cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT including the mandibular 1st molar region were identified from the Prince Philip Dental Hospital archive and analyzed by a single investigator. Morphologic features and location of DLR were studied and presented as 95% confidence intervals.

RESULTS

A total of 398 CBCTs with 716 mandibular first molars were analyzed. The prevalence of DLRs in mandibular first molars on subject based was 20.1% (95% C.I. 16.2-24%). DLR was located 44.5° ± 8.9° (95% C.I. 42.8-46.1°) to the mid-lingual of the mandibular first molar, with a bucco-lingual width 3.3 mm ± 0.5 mm (95% C.I. 3.2-3.4 mm). The mesial furcation entrance was located 4.0 mm ± 0.9 mm (95% C.I. 3.8-4.2 mm) apical to the cemento-enamel junction (CEJ) while the distal was 5.2 mm ± 1.3 mm (95% C.I. 5.0-5.4 mm) from the CEJ. The surface area of the DLR was 106.9 mm² ± 41.2 mm² (95% C.I. 98.9-114.8 mm²).

CONCLUSIONS

Chinese population has a high prevalence of DLRs. The present information is critical for understanding the morphological features of DLR and guide diagnosis and treatment of stage III periodontitis as well as for secondary prevention and supportive care of stage II periodontitis.

CLINICAL RELEVANCE

Little is known about the location and morphology of disto-lingual roots of mandibular 1st molars, yet they are frequently present in patients with Chinese ethnic background, thus complicating diagnosis and treatment. The present study utilized CBCT to analyze the prevalence and morphological features of the mandibular first molar DLR and furcation entrance. It is the first study reporting on the position of the DLR, degree of separation of the furcation, and the surface area of the DLR.

Analysis of the characteristics of periodontal curettes used for scaling the roof of the furcation by manual versus digital method

Abstract Introduction The treatment of periodontal disease in multiradicular teeth with furcation involvement is a challenge for dentists, with unpredictable results. Objective To evaluate the characteristics of the active tip of periodontal curettes used for scaling the furcation roof, comparing the manual versus digital method. Material and method Forty-two Pádua Lima (PL) curettes of the Millennium® brand (n = 6 for each model) were evaluated: PL 1-2, PL 3-4, PL 5-6, PLW 1-2, PLW 3-4, PLW 5 -6, and PLF. The following were measured: total length of the coronary face (CTc, millimeters, mm), total length of the lateral face (CTl, mm), width of the coronary face (Lc, mm), and width of the lateral face (Ll, mm). The measurements were performed in duplicate. Result The results showed that weight varied among the curettes (p <0.05), however the handle diameter was similar for all instruments (p> 0.05). Considering that seven different types of curettes were evaluated, the parameters of CTl and Ll showed a statistical difference for all evaluated curettes (7: 7 ratio), with higher values for the caliper method compared to the software (p <0.05). There was a statistically significant difference between assessment methods for CTc and Lc measurements (p <0.05), showing that there was a coincidence of values in the proportion of 4:7 for measurements of CTc and 5:7 for Lc. Conclusion The comparison between methods generally resulted in lower values and greater variation for the digital method, thus favoring the use of the manual method to measure the active tip of periodontal curettes.

Evaluation of root morphology of maxillary and mandibular second molars lost due to periodontitis

BACKGROUND AND OBJECTIVE

Little is known about the anatomical characteristics of root morphology in molars lost due to periodontal reason. The aim of this study was to study root morphology in maxillary and mandibular molars lost due to periodontitis by investigating the frequency of root fusion, classifying fusion types, and measuring radicular groove depth by micro-computed tomography.

MATERIAL AND METHODS

Ninety-eight posterior teeth were collected from 87 Japanese patients during the study period. Of these, maxillary (N = 36) and mandibular (N = 22) second molars lost most frequently were assessed for root fusion and morphology.

RESULTS

The 36 maxillary second molars included nine (25%) teeth with a single root, 14 (39%) with two roots, and 13 (36%) with three roots. Of the 23 maxillary second molars with fused (1 and 2) roots, there were 11 (48%), 2 (9%), 1 (4%), 1 (4%), 3 (13%), and 5 (22%) teeth with root types 1-6, respectively. The 22 mandibular second molars comprised 14 (64%) teeth with a single root, 7 (32%) with two roots, and one (4%) with three roots. Of the 14 mandibular second molars with a fused (1) root, 12 (86%) had a C-shaped root and two (14%) had a non-C-shaped root.

CONCLUSION

We observed a higher frequency of root fusion in the present study compared with that reported by previous studies using randomly selected second molars.

Morphometric study of the root anatomy in furcation area of mandibular first molars

Furcation involvement in periodontal disease has been a challenge for the dentist.

Comparative Study of Ultrasonic Instrumentation for the Non-Surgical Treatment of Interproximal and Non-Interproximal Furcation Involvements

BACKGROUND

The aim of this clinical trial was to compare the outcome of non-surgical treatment of interproximal and non-interproximal Class II furcation involvements.

METHODS

Thirty-eight patients presenting at least one Class II furcation involvement that bled on probing with a probing depth (PD) > or = 5 mm were recruited. Furcation involvements were grouped as either buccal and lingual furcation involvements (BLFI) or interproximal furcation involvements (IFI). The following clinical outcomes were evaluated: visible plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), PD, and relative horizontal attachment level (RHAL). N-benzoyl-l-arginine-p-nitroanilide (BAPNA) testing was used to analyze trypsin-like activity in dental biofilm. All parameters were evaluated at baseline and 1, 3, and 6 months after non-surgical subgingival instrumentation.

RESULTS

Six months after treatment, both groups had similar means of RAL and RHAL gain (P >0.05). These variables were 1.22 and 1.07 mm in the IFI group and 1.38 and 1.20 mm in the BLFI group, respectively. The PD reduction was significantly greater in the BLFI group than in the IFI group (2.59 and 2.11 mm, respectively; P <0.05). The BLFI group presented fewer sites with PD > or = 5 mm than the IFI group at all post-treatment periods. At 6 months, the BAPNA test showed that only the BLFI group had values significantly different from baseline. This means that the BLFI group had significantly lower BAPNA values compared to the IFI group at 6 months.

CONCLUSION

Buccal and lingual Class II furcation involvements respond better to non-surgical therapy compared to interproximal Class II furcation involvements.

Topographic study of extracted molars with advanced furcation involvement: furcation entrance dimension and molar type

This study investigated the topography of the furcation entrance dimension (FED) on molars with advanced furcation involvement (FI). The sample pool consisted of 169 maxillary and mandibular molars from a group of 165 individuals with severely advanced periodontal destruction. The subjects included men and women aged 24 to 84 years (mean, 47.8 +/- 7.2 years). The FEDs of the maxillary buccal, mesial, and distal surfaces as well as the mandibular buccal and lingual surfaces were measured under a stereomicroscope and clarified into grades I (FED < 0.55 mm), II (0.55-0.75 mm), and III (> 0.75 mm) using automatic grading system software designed by our research associates. The differences and relationships among molar location, furcation site, and FED grade were analyzed using the chi-square test. There was a significant difference among buccal (BFED), mesial (MFED), and distal (DFED) FEDs in both the maxillary first (chi2(4) = 58.915, p < 0.001) and second (chi2(4) = 66.839, p < 0.001) molars. The relationship between molar type and FED grade was statistically significant for both the BFED (p < 0.001) and the DFED (p < 0.001) of maxillary molars, as well as for both the BFED (p < 0.0001) and LFED (p < 0.0001). The difference in FED grade between the first and second molars was statistically significant in both maxillary (p < 0.001) and mandibular (p < 0.0001) molars. There was a significant relationship between FED grade and tooth location at molars with advanced FI.

Position paper: sonic and ultrasonic scalers in periodontics. Research, Science and Therapy Committee of the American Academy of Periodontology

Ultrasonic and sonic scalers appear to attain similar results as hand instruments for removing plaque, calculus, and endotoxin. Ultrasonic scalers used at medium power seem to produce less root surface damage than hand or sonic scalers. Due to instrument width, furcations may be more accessible using ultrasonic or sonic scalers than manual scalers. It is not clear whether root surface roughness is more or less pronounced following power-driven scalers or manual scalers. It is also unclear if root surface roughness affects long-term wound healing. Periodontal scaling and root planing includes thorough calculus removal, but complete cementum removal should not be a goal of periodontal therapy. Studies have established that endotoxin is weakly adsorbed to the root surface, and can be easily removed with light, overlapping strokes with an ultrasonic scaler. A significant disadvantage of power-driven scalers is the production of contaminated aerosols. Because ultrasonics and sonics produce aerosols, additional care is required to achieve and maintain good infection control when incorporating these instrumentation techniques into dental practice. Preliminary evidence suggests that the addition of certain antimicrobials to the lavage during ultrasonic instrumentation may be of minimal clinical benefit. However, more randomized controlled clinical trials need to be conducted over longer periods of time to better understand the long-term benefits of ultrasonic and sonic debridement.

Anatomic characteristics of the furcation and root surfaces of molar teeth and their significance in the clinical management of marginal periodontitis

Treatment of periodontitis which involves the furcation area of molar teeth has always been a challenge. Sixty extracted human molar teeth were used for an anatomic study to clarify the possible morphologic factors which may affect the diagnosis, prognosis, and clinical management of periodontally involved teeth. Teeth were embedded in methylmethacrylate and cut in 70 microm cross sections from the cementoenamel junction to the apex. Cervical enamel projection, root and root trunk lengths, root proximities as well as depths of root concavities coronally, apically, and at the furcation roof were measured. Cervical enamel projections were observed in 30% of the teeth examined. The shortest root trunk was found at the buccal aspect of mandibular first molars, permitting furcation involvement at early stages of periodontal disease. The most apically located furcation was found at the distal site of maxillary first molars. Furcation roofs showed severe concavities and complex cementum morphology. Teeth exhibiting cervical enamel projection were found to have deeper root concavities compared to teeth without cervical enamel projection and mesial roots of mandibular molars possessed greater furcal concavities than distal roots. The presence of root concavities complicates the diagnosis of furcation involvement and restricts access of periodontal instruments, resulting in incomplete treatment. Furcation anatomy may also influence the long-term prognosis of the teeth by favoring the retention of bacterial deposits and making oral hygiene procedures almost impossible. The present study shows that knowledge of a tooth's unique anatomic characteristics is a prerequisite for effective periodontal therapy.

Bacterial morphotypes and early cellular responses in clinically infected and non-infected sites after combination therapy of guided tissue regeneration and allograft

OBJECTIVES

To compare the bacterial morphotypes and early cellular responses in periodontally treated sites with and without pus formation after a combination of guided tissue regeneration (GTR) and allograft therapy.

METHODS

45 subjects with 80 sites having periodontal lesions with moderate to deep pockets and angular bone defects participated. 28 treated sites in 25 patients were included in the studies. 14 sites suffered from symptoms and signs of infection with pus formation during the healing period were assigned to the pus (P) group. Another 14 sites had asymptomatic healing and were assigned to the non-pus (NP) group. The GTR membranes were retrieved 4-6 weeks after surgery and processed for SEM examination. The bacterial morphotypes on the membranes were observed and photographed. Bacterial adhesion score (BAS, 0-5) and the presence of leukocytes and fibroblasts were estimated from photographs.

RESULTS

The results showed that large numbers of bacteria (high BAS) were present on both sides of the coronal 2/3 of the membrane in both groups, irrespective of clinical conditions. At the apical 1/3 of the membrane, moderate numbers of bacteria were still found on the outer side in the P group. The BAS of rod-shaped bacteria were significantly higher in the P group than that of the NP group on the outer coronal 2/3 of the membrane. The frequency of the presence of fibroblasts (18.5%) at the apical 1/3 of the inner (tooth facing) side of the P group was much lower than that of the same location (28.6-29.6%) in the NP group. The presence of leukocytes and fewer numbers of fibroblasts on the GTR membrane were associated with greater BAS for rod- and filament-shaped bacteria.

CONCLUSIONS

GTR membranes are commonly colonized by oral bacteria during retention, even on uncomplicated and tissue covered portions. The overt infection clinically (pus group) of the membrane-allograft treated sites is associated with a significantly elevated BAS of rod-shaped bacteria, and may be closely related to the occurrence of its adverse early healing responses (inflammation, pus formation, fewer fibroblasts and greater accumulation of leukocytes).

Cervical enamel projection and intermediate bifurcational ridge correlated with molar furcation involvements

In this study, we investigated the cervical enamel projection (CEP) and intermediate bifurcational ridge (IBR) correlated with localized molar furcation involvement (FI). Study samples consisting of 87 hopeless permanent mandibulars (56 first and 31 second molars), which required extraction for periodontal therapy, were randomly collected from the School's Dental Clinic. The furcal defects, CEPs, and IBRs of molars were diagnosed via clinical probing, periapical radiographs, and inspection of ground tooth sections of extracted teeth with a stereomicroscope. Prevalence and distribution of molars with CEPs and/or IBRs were also analyzed. Probing depths (PD), clinical attachment loss (CAL), gingival index (GI), and plaque index (PLI) were measured for the buccal and lingual surfaces of molar furcal areas. Moreover, the relationships between the molar FI with and without CEPs and IBRs and periodontal status were analyzed using Student's paired t-test. Based on those results, we can conclude the following: 1) among 87 molars with FIs examined, 63.2% (55/87) had cervical enamel projections and bifurcational ridges, and the prevalence was greatest in mandibular first (67.9%, 38/56) and second (54.8%, 17/31) molars; and 2) the differences in mean PD, CAL, PLI, and GI between the molars with and without CEPs and IBRs were highly significant (P < 0.001) in the mandibular first and second molars.

Relationship between molar root fusion and localized periodontitis

We investigated the relationship between molar root fusion and localized periodontitis in this study. A total of 143 individuals (1,109 molars) aged 23 to 68 years were examined for the presence of molar root fusion at diseased and healthy sites. Molar root fusions were diagnosed by periapical radiographs and clinical probing. Periodontal parameters measured included probing depth (PD), clinical attachment loss (CAL), gingival index (GI), and plaque index (PLI) around fused molars. Results indicated that the prevalence of molar root fusions in males and females was 15.2% (93/612) and 32.2% (160/497), respectively. The distribution of molars with root fusions occurs in the following order: maxillary second molars (51.8%), mandibular second molars (32.3%), maxillary first molars (5.7%), and mandibular first molars (0%). Statistically significant differences were observed between molar root fusions at healthy and diseased sites with respect to PLI, GI, PD, and CAL. The highest prevalence of molar root fusion was observed in females.

Types and dimensions of root trunk correlating with diagnosis of molar furcation involvements

The objective of the present study was to investigate the possible correlation of dimension, location, prevalence, and types of root trunk with molar furcation involvement (FI). The samples used in the study include 166 maxillary molars (70 1st and 96 2nd molars) and 200 mandibular molars (103 1st and 97 2nd molars). The dimensions of the root trunks and root lengths were measured with an electric caliper and their means and standard deviations calculated. The types of root trunks were identified by the ratio of root trunk dimension to root length and classified as types A, B, and C. The results may be summarized as follows. (1) Short-root trunks were more commonly found buccally, whereas long-root trunks were more commonly found mesially, in both maxillary molars. (2) Short-root trunks were most commonly found buccally, whereas long-root trunks were more commonly found lingually in both mandibular molars. (3) Long-root trunks were more commonly found on the 2nd molars than on the 1st molars. (4) Long-root trunks were associated with short root length. (5) There is a strong correlation between vertical length and type of root trunk and FI. The findings of the study indicated that an awareness of root trunk type together with horizontal and vertical attachment levels in molar FI may be helpful in the prognosis, diagnosis, and treatment of molar FI.

Proof of efficacy of different modified sonic scaler inserts used for debridement in furcations--a dummy head trial

The purpose of this study was to determine the suitability of different scaling instruments for surgical removal of hard and soft bacterial deposits and for the removal of soft accretions only for maintenance treatment within furcations. 12 upper and 12 lower plastic replicated molars, with through-and-through furcations, were instrumented 3 x with 4 different types of instruments: (1) hand instruments; (2) a conventional sonic scaler insert; (3) a set of 3 modified sonic scaler inserts with budded tips and different angulated shafts; (4) a set of 3 sonic scaler inserts with a plastic-coating and different angulated shafts. The plastic replicas were fixed in a dummy head without any replicated soft tissues. In the furcation area, an easily removable surface coating material was applied to the teeth to represent the "plaque" and a second, more stubborn lacquer layer representing "calculus/cementum". Following instrumentation, the following parameters were recorded to assess efficacy; time required for instrumentation, loss of weight, depth of substance removal at the furcation entrance, % of furcation area instrumented, whereby removal of these 2 layers was judged separately. Only minor differences were observed between hand instruments, conventional and budded sonic scaler inserts as to loss of weight, depth of substance loss and area instrumented. The plastic-coated sonic scaler inserts were just as effective in surface layer removal representing "plaque" as the 3 other instruments, but resulted in less loss of weight and less depth of substance removal. In conclusion, the more aggressive hand instruments, the conventional and budded sonic scaler insert, are preferably used for the surgical phase to increased ease of entry into the furcation dome. An effective debridement of the furcation roof seems only possible with an odontoplastic, for which a furcation is fitted to the instrument by means of an intensive instrumentation, thus leading to weight loss and pronounced substance removal. The plastic-coated sonic scaler inserts seems to be a reasonable choice for maintenance treatment within furcation, since this treatment phase is usually restricted to removal of soft bacterial deposits.