Bone loss of furcated mandibular molars. A longitudinal study

Maxillary root amputation: Case report with a 14-year-follow-up and updated mini review

Root resection is performed to create a maintainable furcation area in teeth with advanced periodontitis. However, the long-term feasibility of this treatment remains controversial. We present a case in which distal root resection in a maxillary molar successfully preserved the form and function of the dentition for approximately 14 years.

Tooth loss and radiographic bone loss in patients without regular supportive care: A retrospective study

BACKGROUND

Very few studies have investigated the effect of patient and site factors on periodontal progression and long-term tooth loss in populations with minimal dental care. The aim of this retrospective study was to assess tooth loss and radiographic bone loss over at least 5 years in patients attending a national-health service primary care practice in Sicily and undergoing no regular care.

METHODS

Records of two hundred consecutive patients with at least 5 years follow-up were screened and demographic, clinical and radiographic data were retrieved. Analyses of associations between patient and site factors and tooth loss were performed.

RESULTS

After excluding not suitable patients, a total of 159 patient records with clinical and radiographic data with average 8.6 years follow-up were included. One hundred of these patients had no professional mechanical plaque removal (PMPR) carried out throughout the study follow-up. Nearly 65% of patients lost at least 1 tooth during the follow-up period, with a total of 400 extracted teeth (for periodontal and non-periodontal reasons). The annual tooth loss rate was slightly higher for "no PMPR" (untreated) patients (0.30 teeth/patient/year) compared with patients who had PMPR (0.27 teeth/patient/year). On a patient-level, only reduced frequency of daily tooth brushing was associated with tooth loss at logistic regression, whereas staging, grading and diagnosis of caries were associated with rates of tooth loss/year. At multilevel analysis including patient- and tooth-factors, age, diagnosis of caries and endodontic disease and percentage of bone loss at baseline were associated with tooth loss.

CONCLUSION

This study confirms the importance of tooth brushing, initial bone loss, caries and endodontic disease in predicting tooth survival in a primary care setting.

Correlation of the interdental and the interradicular bone loss: A radiovisuographic analysis

Background:

Presence of furcation involvement indicates advanced periodontitis, and a potentially less-favorable prognosis, for the affected tooth and its diagnosis has always been an enigma. The present study was carried out to measure and correlate the interdental and interradicular bone loss in patients suffering from periodontitis using radiovisuography (RVG) for the purpose of early furcation diagnosis.

Materials and Methods:

A total of 50 patients suffering from chronic generalized periodontitis and with furcation involvement in mandibular molars were selected. Under standardized conditions, RVGs were taken and the morphologic measurements defining the furcation areas were recorded and analyzed.

Result:

Interradicular bone loss of about 0.8 mm or more, was observed in the study subjects only when the bone loss at the interdental area was minimal of 3.7 mm. The correlation between the interradicular and the interdental bone loss was statistically highly significant (T-test, P < 0.001). A stronger correlation was observed in subjects above 40 years of age as compared with the younger subjects. There was not much difference in the degree of correlation between the interradicular and the interdental bone loss when compared in the context of gender.

Conclusion:

The very first millimeter of interradicular bone loss was seen when the interdental bone loss was around 4 mm. Therefore, to detect the earliest lesions of furcations, the interdental bone loss can be kept as an approximate guide for the comprehensive diagnosis and management of such sites/patients. The current investigation paves the path for future longitudinal studies with larger samples to ascertain these findings.

Factors Influencing the Outcome of Regenerative Therapy in Mandibular Class II Furcations: Part I

BACKGROUND

Factors influencing the outcome of regenerative therapy of Class II furcations are incompletely and poorly understood. The purpose of this 24-month prospective study was to examine the relationship of patient-, site-, and treatment-related factors to the clinical closure of randomly selected mandibular Class II furcations. Results of therapy were evaluated at 1 and 2 years postoperatively. One-year outcome data are presented in this report.

METHODS

A total of 43 otherwise healthy individuals with chronic periodontitis (26 male, 17 female), 36 to 70 years of age, completed the 12-month evaluation of the study. Entry criteria included clinical and radiographic evidence of two or more mandibular facial Class II furcation defects (> or = 3 mm horizontal probing depth). Surgical therapy was completed by four periodontists (two each) in either a university clinic or private practice. Each patient contributed two furcation defects that were treated by combination therapy using an expanded polytetrafluoroethylene (ePTFE) membrane and demineralized freeze-dried bone allograft (DFDBA). Clinical measurements included a gingival index, plaque index, mobility, and, referencing an occlusal stent, probing depth (PD), probing attachment level-vertical (PAL-V), and probing attachment level-horizontal (PAL-H). Multiple linear measurements were recorded for each site clinically and after surgical debridement to characterize defect morphology, root configuration, and barrier placement. Defect volume was computed mathematically. Postsurgical maintenance care was provided at 1 to 2, 4, 6, and 8 weeks, and then biweekly until 3 months, with subsequent supportive periodontal maintenance visits at 3-month intervals. The clinical status of the furcation (open or closed), measured by a non-treating periodontist at 1 and 2 years, was the primary outcome measure. The association of patient-related factors (e.g., smoking), site-related factors (e.g., root configuration and defect morphology), and treatment-related factors (e.g., membrane exposure) to clinical status of furcations was assessed using random effects hierarchical logistic regression analysis, controlling for design and demographic variables. Non-parametric analysis was used for specific group comparisons.

RESULTS

Complete clinical closure was achieved in 74% of all sites. Of the residual furcation defects, 68% were reduced to Class I. No defects progressed to Class III. Significant improvements in mean PD and PAL-V were obtained following surgical therapy. Although the proportion of sites demonstrating complete furcation closure was comparable for smokers and non-smokers, the proportion of Class II residual defects was significantly higher among smokers than non-smokers (62.5% versus 14.3%, respectively). Increases in presurgical PAL-H were associated with monotonic decreases in the percentage of sites demonstrating complete clinical closure, with only 53% of lesions > or = 5 mm responding with complete closure. Similarly, significant reductions in the frequency of clinical closure were associated with increases in the distance between the roof of furcation and crest of bone, roof of furcation and base of defect, depth of horizontal defect, and divergence of roots at the crest of bone.

CONCLUSIONS

The successful clinical closure of Class II furcations was achievable at 1 year following combination therapy with an ePTFE membrane and DFDBA. The highest frequency of clinical furcation closure was observed in early Class II defects. Furcations with vertical or horizontal bone loss of 5 mm or greater responded with the lowest frequency of complete clinical closure. Nevertheless, complete furcation closure was achievable in 50% of molars with extensive bone loss. Also, 15 out of 22 (68%) of all residual defects were reduced to Class I and only seven (8%) failed to improve, demonstrating that successful clinical resolution of advanced defects remains an attainable goal.

Immediate implant in fresh extraction socket of resected mandibular first molar: a preliminary clinical report

This study presents a new technique that involves resection of the affected mesial root in a lower mandibular molar with immediate implant placement in its extraction socket. This technique offers a treatment option for mandibular molars affected by local periapical infection, bifurcation involvement, or buccolingual fractures. Extraction of such molars usually creates a large edentulous span and subsequent restorative problems. The patient is provided with a crown that is supported by an implant in the resected mesial root site and the retained distal root. The crown is esthetic and functional and easy to maintain. This technique was successfully applied on five patients.

Clinical comparison of microporous biocompatible composite of PMMA, PHEMA and calcium hydroxide grafts and expanded polytetrafluoroethylene barrier membranes in human mandibular molar Class II furcations. A case series

BACKGROUND

Class II furcations present difficult treatment problems. Several treatment approaches to obtain furcation fill have been used with varying success.

METHODS

The response of mandibular Class II furcations to treatment with either a microporous biocompatible composite of PMMA (poly-methyl-methacrylate), PHEMA (poly-hydroxyl-ethyl methacrylate) and calcium hydroxide graft synthetic bone (HTR) replacement graft material; ePTFE barrier membrane; or a combination of the two was evaluated in trios of mandibular molars with Class II furcations in 8 patients with moderate to advanced periodontitis. Following initial preparation, full-thickness flaps were raised in the areas being treated, the bone and furcation defects debrided of granulomatous tissue, and the involved root surfaces mechanically prepared and chemically conditioned. By random allocation, HTR, ePTFE, or a combination of both was placed into and/or fitted over the furcations, packed and/or secured in place, and the host flap replaced or coronally positioned with sutures. Postsurgical deplaquing was performed every 10 days leading up to ePTFE removal at approximately 6 weeks. Continuing periodontal maintenance therapy was provided until surgical reentry at 6 months for documentation and any further necessary treatment.

RESULTS

Direct clinical measurements demonstrated essentially similar clinical results with all 3 treatments for bone and soft tissue changes. There were no statistically or clinically significant differences except for better horizontal amount and percent defect fill with HTR alone. Four of 8 furcations became Class I clinically with HTR alone, 5 of 8 became Class I with ePTFE alone, and 5 of 8 with combination treatment. The only complete furcation closure occurred with HTR.

CONCLUSION

The findings of this study suggest essentially equal clinical results with HTR bone replacement graft material alone, ePTFE barrier alone, and a combination of the two in mandibular molar Class II furcations. However, a real difference may not have been detected based on the small number of subjects in the study.

A comparison of the success of root resected molars and molar position implants in function in a private practice: results of up to 15-plus years

BACKGROUND

When faced with a furcated molar, today's clinician must decide between a number of treatment options, including root resection, tooth removal, and implant placement. This paper assesses the results in one private clinical practice of root resection and subsequent restoration or molar implant placement and subsequent restoration. Clinical considerations in treatment selection are discussed.

METHODS

A retrospective analysis of treated patients was carried out by examining active and inactive patient charts. When patients had discontinued therapy, every effort was made to determine the reason for leaving the private practice, so as to assess the impact of previously undocumented treatment failure on the statistics in question.

RESULTS

A total 701 root resected molars and 1,472 molar implants were evaluated after > or = 15 and 13 years in function, respectively. Resection of the distal root of a mandibular molar demonstrated the lowest success rate (75%). All other success rates for various root resected molars in function ranged from 95.2% to 100%. Lone standing implants in second molar positions demonstrated the lowest success rate (85%). All other implant use in molar positions demonstrated a success rate ranging from 97.0% to 98.6%. Root resected molars and molar implants demonstrated the highest degree of failure when they were lone standing terminal abutments. Seven out of 23 (30.4%) root resected molar failures, and 17 of 45 (37.8%) of the molar implant failures were associated with untreated parafunction. Cumulative success rates were 96.8% for root resected molars and 97.0% for molar implants. Success and failure are discussed by tooth and/or implant position, and resected root, where applicable. Possible ramifications of these findings upon treatment planning are also reviewed.

CONCLUSIONS

Both molar root resection and appropriate restoration and molar implant placement and restoration demonstrated a high degree of success in function. However, this success rate is markedly affected when either the root resected molar or molar implant is a lone standing terminal abutment. Care must be taken to choose the appropriate treatment modality for a given patient scenario.

Clinical comparison of bioactive glass bone replacement graft material and expanded polytetrafluoroethylene barrier membrane in treating human mandibular molar class II furcations

BACKGROUND

Class II furcations present difficult treatment problems and historically several treatment approaches to obtain furcation fill have been used.

METHODS

The response of mandibular Class II facial furcations to treatment with either bioactive glass (PG) bone replacement graft material or expanded polytetrafluoroethylene (ePTFE) barrier membrane was evaluated in 27 pairs of mandibular molars in 27 patients with moderate to advanced periodontitis. Following initial preparation, full thickness flaps were raised in the area being treated, the bone and furcation defects debrided of granulomatous tissue, and the involved root surfaces mechanically prepared and chemically conditioned. By random allocation, PG or ePTFE was placed into or fitted over the furcations, packed or secured in place, and the host flap replaced or coronally positioned with sutures. Postsurgical deplaquing was performed every 10 days leading up to ePTFE removal at about 6 weeks. Continuing periodontal maintenance therapy was provided until surgical reentry at 6 months for documentation and any further necessary treatment.

RESULTS

Direct clinical measurements demonstrated essentially similar clinical results with both treatments for bone and soft tissue changes. There were no statistically or clinically significant differences (e.g., mean horizontal furcation fill 1.4 mm PG, 1.3 mm ePTFE; mean percent horizontal furcation fill 31.6% PG, 31.1% ePTFE, both P>0.85). Seventeen of the PG treated and 18 of the ePTFE furcations became Class I clinically and 1 furcation completely closed clinically with each treatment. Intrapatient comparisons showed similar horizontal furcation responses with both treatments.

CONCLUSION

The findings of this study suggest essentially equal clinical results with PG bone replacement graft material and e-PTFE barriers in mandibular molar Class II furcations. PG use was associated with simpler application and required no additional material removal procedures.

Six-year clinical evaluation of HTR synthetic bone grafts in human grade II molar furcations

A biocompatible microporous composite of PMMA (poly-methyl-methacrylate), PHEMA (poly-hydroxy-ethyl-methacrylate) and calcium hydroxide bone replacement graft material (Bioplant HTR Synthetic Bone) was evaluated in 16 maxillary molar and 10 mandibular molar Grade II furcations in 13 patients. Following initial preparation, full thickness flaps were raised to gain access to the furcations; mechanical hand and ultrasonic root and defect debridement and chemical tetracycline root preparation were performed; furcation and adjacent osseous defects in each patient were grafted with HTR Synthetic Bone; and the host flaps replaced or slightly coronally positioned. Weekly, then monthly deplaquing was performed until surgical re-entry at 6-12 months. Patients were then followed on approximate 3-month recalls for > or = 6 yr. Evaluation of the primary clinical outcome of furcation grade change showed that in the maxilla 5/16 furcations were clinically closed, 9/16 were Grade I, and 2/16 remained Grade II; while in the mandible 3/10 were clinically closed, 5/10 were Grade I, and 2/10 remained Grade II. Other significant clinical changes included decrease in mean horizontal furcation probing attachment level from 4.4 mm at surgery to 2.2 mm at re-entry to 2.0 mm at 6 yr, decrease in probing pocket depth from 5.4 mm at surgery to 3.0 mm at re-entry to 3.2 mm at 6 yr, and improvement in vertical clinical probing attachment level from 5.4 mm at surgery to 4.2 mm at re-entry to 4.1 mm at 6 yr (all p < 0.05 from surgery to re-entry and surgery to 6 yr, n.s. from re-entry to 6 yr via ANOVA). These favorable results with HTR polymer are similar to several reports with other graft materials and with GTR barriers, and suggest that HTR polymer may have a beneficial effect in the clinical management of Grade II molar furcations.

Observer performance in locating the bifurcation in mandibular molars on periapical radiographs

The ability to identify radiographically the bifurcation in mandibular molars and the influence of morphological factors on the observers' decisions were investigated in 10 dry mandibles. Standardized periapical radiographs were obtained with and without lead markers in the bifurcation. Then 23 observers marked the bifurcation on tracing paper placed on the radiographs. The distance between the 'true' bifurcation (the lead indicators) and the observers' markings was assessed. On average, it was identified at a point 0.26 mm (s.d. 0.5) apical to its 'true' location on the first molar, and 0.65 mm (s.d. 1.15) coronal on the second molar. Interobserver variation for first and second molars was 0.5 mm and 1.06 mm respectively. Corresponding intraobserver variation was 0.47 mm and 1.14 mm. Of the four morphological characteristics analysed, the mesiodistal width of the bifurcation was found to have the strongest influence on the accuracy. It was concluded that the wide discrepancy in the ability of the observers to locate the bifurcation could be largely attributed to intraindividual variation.

Computer-assisted densitometric image analysis (CADIA) for the assessment of alveolar bone density changes in furcations

The purpose of this study was to test the applicability of computer-assisted densitometric image analysis (CADIA) for the quantitative assessment of alveolar bone density changes in furcations of multirooted teeth. In 21 patients, standardized radiographs were obtained immediately after and at 1, 6 and 12 months after periodontal flap procedures. Digitized images were obtained by means of a video-camera combined with an image processor that was linked to a computer. Quantitative information regarding density changes within windows covering furcation areas was obtained after superimposition and grey-level correction of images to be compared. 1 month after flap reflection, significantly more density loss was obtained in test furcations exposed to periodontal surgery, compared to the density changes in control furcation exposed to scaling and root planing. At 12 months, however, significantly greater increase in density was measured in test furcations compared to the 1-month results. The radiographic data were compared to the clinical parameters. In test furcations, there was a negative correlation of r = -0.52 between the GI and the loss in density at 1 month, and a negative correlation of r = -0.61 between the loss in density at 6 months and the probing attachment level at 12 months. These results indicate that CADIA may give valuable additional diagnostic information regarding alveolar bone density changes in furcations in studies on periodontal therapy.

Evaluation of furcation region response to periodontal therapy

Five hundred fifty-eight molars were treated with one of four types of periodontal therapy: coronal scaling (CS); root planing (RP); modified Widman surgery (MW); or flap with osseous resectional surgery (FO). This report presents the probing depth and probing attachment changes in the furcation region following therapy and two years of maintenance follow-up. All types of therapy were effective in reducing probing depths. FO was the most effective in reducing probing depth followed by MW, RP, and CS. Reduction in probing depth was primarily due to gingival recession. FO resulted in a loss of probing attachment in both a vertical and horizontal direction following therapy. Following two years of maintenance care, sites treated with FO continued to exhibit a mean net loss of vertical probing attachment. A mean net loss of horizontal probing attachment was present after two years of maintenance care, regardless of the treatment modality employed. Many more sites were initially removed during osseous resectional surgery to achieve treatment criteria than were initially removed from the other groups. FO treated teeth demonstrated a lesser percentage of furcation sites demonstrating clinically significant breakdown during the two years of maintenance care.

A simple paralleling instrument for superimposing radiographs of the molar regions

A simple, disposable paralleling device to produce identical radiographs of the maxillary and mandibular molar regions is described. Its precision was determined by taking serial radiographs of several patients. No deformations were found when enlargements of the radiographs were made. Identical tracings were produced during analysis with a computer-assisted densitometric technique. The new device is inexpensive and could be used advantageously for qualitative and quantitative longitudinal studies.

Densitometric analysis of lower molar interradicular areas in superposable radiographs

Superposable radiographs of lower molar areas were obtained by means of a specially designed film holder and a gnathostat maintained in a constant position with respect to long-cone radiological equipement. A quantitative evaluation of the bone mass in the interradicular area was obtained by scanning the area under a photodensitometer. A photodensitometric scan of the image of an aluminium wedge adapted to each radiograph was also performed. This allowed the transformation, with the aid of a computer, of the photodensitometric recording of bone into a tracing of mm of aluminium equivalents. The reproducibility and precision of the method were verified by comparing magnifications of repeated radiographs, by photodensitometric readings of radiographs developed in different batches and by repeated quantitative readings of the same film. The method allowed one, for instance, to follow quantitatively the healing of a radiographically visible periapical lesion. It was also used to evaluate quantitatively, in the interradicular area, bone changes which could not be seen with the marked eye.

Longitudinal radiographical study on the rate of alveolar bone loss in patients of a dental school

Two sets of radiographs, taken at an interval of 4-14 years in 105 patients of a dental school, were examined in order to determine the rate of resorption of alveolar bone. The percentage loss of maximum alveolar bone height was measured in the interproximal and interradicular sites by means of the Schei ruler. The average percentage of interproximal bone resorption was 0.51% (0.07 mm) per year. Age, sex, professional status, type of periodontal treatment and general state of health did not seem to affect the annual resorption rate. However, crowned teeth had a significantly greater rate of resorption than uncrowned teeth. Loss of bone tended to be more rapid in interdental as compared to interradicular areas. A positive and statistically significant correlation was found between initial resorption and annual tooth loss.