Root grooves: a risk factor in periodontal attachment loss

Evaluation of the relationship between periodontal bone destruction and mesial root concavity of the maxillary first premolar

BACKGROUND

The purpose of this study was to investigate the morphology of maxillary first premolar mesial root concavity and to analyse its relation to periodontal bone loss (BL) using cone beam computed tomography (CBCT) and panoramic radiographs.

METHODS

The mesial root concavity of maxillary premolar teeth was analysed via CBCT. The sex and age of the patients, starting position and depth of the root concavity, apicocoronal length of the concavity on the crown or root starting from the cementoenamel junction (CEJ), total apicocoronal length of the concavity, amount of bone loss both in CBCT images and panoramic radiographs, location of the furcation, length of the buccal and palatinal roots, and buccopalatinal cervical root width were measured.

RESULTS

A total of 610 patients' CBCT images were examined, and 100 were included in the study. The total number of upper premolar teeth was 200. The patients were aged between 18 and 65 years, with a mean age of 45.21 ± 13.13 years. All the teeth in the study presented mesial root concavity (100%, n = 200). The starting point of concavity was mostly on the cervical third of the root (58.5%). The mean depth and buccolingual length measurements were 0.96 mm and 4.32 mm, respectively. Depth was significantly related to the amount of alveolar bone loss (F = 5.834, p = 0.001). The highest average concavity depth was 1.29 mm in the group with 50% bone loss. The data indicated a significant relationship between the location of the furcation and bone loss (X2 = 25.215, p = 0.003). Bone loss exceeded 50% in 100% of patients in whom the furcation was in the cervical third and in only 9.5% of patients in whom the furcation was in the apical third (p = 0.003).

CONCLUSIONS

According to the results of this study, the depth of the mesial root concavity and the coronal position of the furcation may increase the amount of alveolar bone loss. Clinicians should be aware of these anatomical factors to ensure accurate treatment planning and successful patient management.

Periodontitis was associated with mesial concavity of the maxillary first premolar: a cross-sectional study

The association between the anatomical features of teeth and the pathogenesis of periodontitis is well-documented. This study aimed to evaluate the influence of the mesial concavity of the maxillary first premolar on periodontal clinical indices and alveolar bone resorption rates. Employing a cross-sectional design, in 226 patients with periodontitis, we used cone beam computed tomography(CBCT) to examine the mesial concavity and alveolar bone resorption of 343 maxillary first premolar. Periodontal clinical indicators recorded by periodontal probing in the mesial of the maxillary first premolar in patients with periodontitis. Our findings indicate that the presence of mesial concavity at the cemento-enamel junction of the maxillary first premolar was not significantly influenced by either tooth position or patient sex (p > 0.05). Nonetheless, the mesial concavity at the cemento-enamel junction of the maxillary first premolar was found to exacerbate alveolar bone resorption and the inflammatory condition (p < 0.05). We infer that the mesial concavity at the cemento-enamel junction of the maxillary first premolar may contribute to localized alveolar bone loss and accelerate the progression of periodontal disease.

Prevalence and Periodontal Conditions of Developmental Grooves in an Italian School of Dentistry and Dental Hygiene: A Cross-Sectional Study

Background: The aim of this cross-sectional study was to (i) determine the prevalence and distribution of developmental grooves in a young population and (ii) to evaluate the local periodontal conditions. Methods: Two hundred and fifty-one students with a mean age of 22.9 ± 4.7, attending the School of Dentistry and Dental Hygiene of Vita-Salute San Raffaele University (Milan, Italy) were included. The subjects underwent a clinical evaluation by two calibrated examiners. The following clinical parameters were recorded for each site presenting a radicular groove and for each corresponding site on an adjacent tooth used as control: probing pocket depth, plaque index, bleeding on probing, recession depth. Results: The prevalence of radicular grooves at patient and tooth level was 15.9% and 5%, respectively. When compared to control sites, the number of teeth with a radicular groove that presented plaque and bleeding on probing was higher. The logistic regression analysis showed that the presence of radicular grooves was significantly associated with the presence of plaque (OR, 6.14, p < 0.001) and of bleeding on probing (OR, 2.91, p = 0.01). Conclusions: The presence of radicular grooves increases the possibility of developing gingival inflammation by acting as a plaque retentive factor.

Association between root taper and root proximity of single-rooted teeth with periodontitis: a cone-beam computed tomography based study

This study aimed to determine the association between the root taper and proximity of single-rooted teeth with periodontitis using cone-beam computed tomography (CBCT). CBCT images of 362 single-rooted teeth from 37 patients were evaluated. This case-control study analyzed 17 participants with stage II and III periodontitis, (n = 161 teeth, periodontitis group) and 20 participants with healthy periodontium (n = 201 teeth, control group). Multiplanar reconstructions were used for proximity measurements, and cross-sectional images for calculating the angle of the root tapers. Root proximity, root length, and root taper were measured. Multivariate binary logistic regression analysis was used to determine association with periodontitis. In the periodontitis group, the upper lateral root-taper was 18.33° ± 3.25° and was significantly higher when compared to the control group (p = 0.001). The root taper of the lateral incisor was associated with the diagnosis of periodontitis (p = 0.01) with an odds ratio of 1.541 according to regression analysis. Root length was also identified as a potential protective parameter. The risk of being diagnosed with periodontitis decreases when root length increases by 0.785 times (p = 0.043). Upper canines in the periodontitis group presented shorter root lengths (p = 0.039) and higher root tapers (p = 0.01). Also, mandibular canines were closer form adjacent teeth in the periodontitis group (p = 0.042). This study indicated that short-root and increased root-taper at specific teeth could be considered as risk indicators for periodontitis.

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.

Micro-computed tomography analysis of the relationship between root canal number and root concavity in maxillary first and second molars in a Japanese population

PURPOSE

The aim of this study was to investigate root canal configurations in maxillary first and second molars from a Japanese population, as well as the relationship between the root canal number and root concavity depth, using micro-computed tomography.

METHODS

Maxillary first (N = 74) and second (N = 70) molars from a Japanese population were used. Virtual horizontal sections were created, and the number of root canals and the degree of root concavity were measured. Mesiobuccal (MB) roots were categorized into Group 1 (with a single root canal) or Group 2 (with two or more root canals). The relationship between the root canal number and root concavity depth was evaluated using the Mann-Whitney U test.

RESULTS

Approximately 51% and 35% of the MB roots in the three-rooted maxillary first and second molars, respectively, had two or more root canals. The depths of the root concavities in maxillary first molars differed significantly between Groups 1 and 2 at the mesial and distal sides of the MB root, in the section 2 mm apical to the furcation area (p < 0.05).

CONCLUSIONS

A significant relationship between the number of root canals and the depth of root concavity in the MB root of the maxillary first molars was observed. Close clinical monitoring is needed during the removal of calculus and cleaning of the root surfaces of maxillary first molars: specifically, excessive removal of cementum and dentin should be avoided, particularly when the molar has already undergone root canal treatment.

Dental prostheses and tooth-related factors

OBJECTIVES

This narrative review summarizes the current evidence about the role that the fabrication and presence of dental prostheses and tooth-related factors have on the initiation and progression of gingivitis and periodontitis.

FINDINGS

Placement of restoration margins within the junctional epithelium and supracrestal connective tissue attachment can be associated with gingival inflammation and, potentially, recession. The presence of fixed prostheses finish lines within the gingival sulcus or the wearing of partial, removable dental prostheses does not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. However, hypersensitivity reactions to the prosthesis dental material can be present. Procedures adopted for the fabrication of dental restorations and fixed prostheses have the potential to cause traumatic loss of periodontal supporting tissues. Tooth anatomic factors, root abnormalities, and fractures can act as plaque-retentive factors and increase the likelihood of gingivitis and periodontitis.

CONCLUSIONS

Tooth anatomic factors, such as root abnormalities and fractures, and tooth relationships in the dental arch and with the opposing dentition can enhance plaque retention. Restoration margins located within the gingival sulcus do not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. Tooth-supported and/or tooth-retained restorations and their design, fabrication, delivery, and materials have often been associated with plaque retention and loss of attachment. Hypersensitivity reactions can occur to dental materials. Restoration margins placed within the junctional epithelium and supracrestal connective tissue attachment can be associated with inflammation and, potentially, recession. However, the evidence in several of the reviewed areas, especially related to the biologic mechanisms by which these factors affect the periodontium, is not conclusive. This highlights the need for additional well-controlled animal studies to elucidate biologic mechanisms, as well as longitudinal prospective human trials. Adequate periodontal assessment and treatment, appropriate instructions, and motivation in self-performed plaque control and compliance to maintenance protocols appear to be the most important factors to limit or avoid potential negative effects on the periodontium caused by fixed and removable prostheses.

Dental prostheses and tooth-related factors

OBJECTIVES

This narrative review summarizes the current evidence about the role that the fabrication and presence of dental prostheses and tooth-related factors have on the initiation and progression of gingivitis and periodontitis.

FINDINGS

Placement of restoration margins within the junctional epithelium and supracrestal connective tissue attachment can be associated with gingival inflammation and, potentially, recession. The presence of fixed prostheses finish lines within the gingival sulcus or the wearing of partial, removable dental prostheses does not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. However, hypersensitivity reactions to the prosthesis dental material can be present. Procedures adopted for the fabrication of dental restorations and fixed prostheses have the potential to cause traumatic loss of periodontal supporting tissues. Tooth anatomic factors, root abnormalities, and fractures can act as plaque-retentive factors and increase the likelihood of gingivitis and periodontitis.

CONCLUSIONS

Tooth anatomic factors, such as root abnormalities and fractures, and tooth relationships in the dental arch and with the opposing dentition can enhance plaque retention. Restoration margins located within the gingival sulcus do not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. Tooth-supported and/or tooth-retained restorations and their design, fabrication, delivery, and materials have often been associated with plaque retention and loss of attachment. Hypersensitivity reactions can occur to dental materials. Restoration margins placed within the junctional epithelium and supracrestal connective tissue attachment can be associated with inflammation and, potentially, recession. However, the evidence in several of the reviewed areas, especially related to the biologic mechanisms by which these factors affect the periodontium, is not conclusive. This highlights the need for additional well-controlled animal studies to elucidate biologic mechanisms, as well as longitudinal prospective human trials. Adequate periodontal assessment and treatment, appropriate instructions, and motivation in self-performed plaque control and compliance to maintenance protocols appear to be the most important factors to limit or avoid potential negative effects on the periodontium caused by fixed and removable prostheses.

Morphological study of proximal root grooves and their influence on periodontal attachment loss

Background:

The etiology of periodontal diseases is multifactorial including both systemic and local causes. Local factors such as grooves on root surfaces contribute a great deal to the causation of periodontal diseases.

Materials and Methods:

Proximal radicular grooves were studied in 150 extracted maxillary and mandibular anterior teeth. Periodontal attachment loss was measured after staining the root surfaces with 0.1% toluidine blue stain. The relationship of the presence and absence of grooves with periodontal attachment loss was also studied.

Results:

The prevalence of proximal root grooves was found to be 86.67%. The prevalence of grooves on maxillary teeth was 43.42% and on mandibular teeth was 56.67%. A greater loss of attachment was present on grooved surfaces than on nongrooved surfaces.

Conclusion:

The proximal radicular grooves present as one of the major etiological factors in periodontal diseases.

Effect of periodontal dressing on non-surgical periodontal treatment outcomes: a systematic review

BACKGROUND

Periodontal dressing has been advocated and showed some positive outcomes for placing over the surgical site after periodontal surgery. However, little is known about its effect on non-surgical therapy.

PURPOSE

The aim of this review was to assess the clinical effect of periodontal dressing when used after non-surgical therapy.

MATERIAL AND METHODS

Two examiners performed an electronic search in several databases for relevant articles published in English up to November 2013. Selected studies were randomized human clinical trials (prospective or retrospective trials) with the clear aim of investigating the effect of periodontal dressing placement upon periodontal non-surgical mechanical therapy. Data were extracted from the included articles for analysis.

RESULTS

Three randomized clinical trials fulfilled the inclusion criteria and thus were included in the data analysis. Statistical analysis could not be carried out due to the lack of clear data of the included studies. However, descriptive analysis showed its effectiveness in improving clinical parameters such as gain of clinical attachment level and reduction of probing pocket depth.

CONCLUSION

Placement of periodontal dressing right after non-surgical mechanical therapy can be beneficial in improving overall short-term clinical outcomes, although more controlled studies are still needed to validate this finding.

Analysis of periodontal attachment loss in relation to root form abnormalities

Purpose

The aim of this study was to explore root shape abnormalities, to investigate the influence of root form abnormalities on periodontal attachment loss, and to gather basic data to assist in the diagnosis and treatment of aggressive periodontitis.

Methods

From January 2010 to June 2012, a survey was conducted of all 3,284 periodontitis patients who visited the Department of Periodontology, Daejeon Dental Hospital, Wonkwang University School of Dentistry. Clinical parameters (probing depth, periodontal attachment loss, missing teeth) were measured and a radiographic examination was performed at the baseline. We classified the root shape abnormality of bicuspids and molars based on Meng classification.

Results

The periodontal attachment loss was the highest at the maxillary first molar (6.03 mm). The loss of the second molar was prominent. Type V deformity was shown to be the most common in the second maxillary and mandibular molars (P<0.05). Type V root shape was associated with the highest attachment loss (P=0.01).

Conclusions

Considering the small population and limited design of this study, definitive conclusions cannot be drawn. We suggest larger scale, methodologically more sophisticated studies that include normal controls and chronic periodontitis patients to clarify whether root form abnormalities are a potential risk factor for aggressive periodontitis.

The relationship between root concavities in first premolars and chronic periodontitis

OBJECTIVE

To evaluate the significance of first premolar root concavity on clinical indices of chronic periodontal disease and alveolar bone defects.

METHODS

Three-dimensional reconstruction by cone beam computed tomography was used to observe root surface anatomy and the type of alveolar bone defect seen in the mesial and distal sites of 272 first premolars from 99 patients who had presented with chronic periodontitis. Periodontal clinical indicators at each site were measured using a Florida Probe Corporation (Gainesville, FL, USA).

RESULTS

The incidence of mesial and distal root concavities of the maxillary first premolars was 100% and 39.3% respectively, and in the mandibular, the incidence was 42.5% and 31.3% respectively. The distributions of the different types of concavities in terms of both age and gender of the patients were not statistically significant. The mean probing depth and clinical attachment loss of the first premolars with root concavities were significantly higher than those without concavity (p < 0.05). Plaque accumulation was significantly different in the premolars with/without root concavities (p < 0.001). The type of alveolar bone defects with concavities was significantly different from those without concavities (p < 0.05). Ramp shape bone defects were dominant for teeth without concavities, while crater shape was seen for teeth with concavities.

CONCLUSION

Root concavities of the first premolars were associated with periodontal disease, and the type of interproximal alveolar bone defect. Root concavities may be important in contributing to local periodontal disease of the first premolars.

Periodontal dressing may influence the clinical outcome of non-surgical periodontal treatment: a split-mouth study

INTRODUCTION

After scaling and root planning (SRP), healing induces the formation of a junctional long epithelium rather than a new connective attachment. We hypothesize that the placement of a periodontal dressing will be able to prevent detachment of coagulum inducing proper healing and improving periodontal parameters.

MATERIALS AND METHODS

This split-mouth study included 30 patients with periodontitis with ages ranging from 35 to 70 years. Probing pocket depth (PD), probing attachment level (PAL), bleeding on probing index (BoP) and plaque index (PI) were assessed before and after therapy. The group of patients received SRP in a span of 24 h. Then, a periodontal dressing was applied on the test side and it was removed after 1 week.

RESULTS

CONTROL GROUP

The difference between PD values at baseline and after therapy was 1.6 ± 0.6 mm. The difference in PAL (ΔPAL) measurement was 1.4 ± 0.4. Test group: there was a greater PD reduction, this being 2.4 ± 0.6 mm on average. The difference in PAL was 2.5 ± 0.4 mm.

CONCLUSIONS

Our results clearly suggest that the use of a periodontal dressing improves the periodontal parameters after an SRP procedure. This is probably due to clot stabilization and prevention of bacterial colonization during wound healing.

Morphometric study of length and grooves of maxillary lateral incisor roots

OBJECTIVE

Root grooves are considered a risk factor for periodontal disease. The purpose of this study was to measure the length of the root of maxillary lateral incisors (MLI), as well as the width and depth of the concavities of their proximal surfaces, and also to determine the prevalence of palato-gingival grooves.

METHODS

the width and depth of root concavities, as well as root length were evaluated in 73 MLI. All teeth were measured using a digital contour measuring instrument for the root grooves and a caliper for evaluating root length.

RESULTS

After statistical analysis (p<0.05) it was possible to confirm: the mean root length on its mesial surface was (15.47+/-1.72 mm), on its distal surface (14.99+/-1.70 mm), on its buccal surface (13.10+/-1.69 mm) and on its lingual surface (12.71+/-1.53 mm); concavities were present in 100% of the samples; concavities were found 2mm, coronally from the CEJ, at the CEJ, and apically up to 8mm; the concavities were wider than deeper; on the mesial surface, the greatest width was (1.05 mm) and the greatest depth was (0.06 mm) both at the CEJ; 5) on the distal surface the greatest width was (0.73 mm) at 6mm apically from the CEJ and the greatest depth was (0.003 mm); the palato-gingival groove was observed in 9.58% of the samples.

CONCLUSIONS

The mesial surface of the maxillary lateral incisor is the longest. The root concavities on the proximal surfaces are present in 100%. One must get acquainted to the morphological variations of roots to enhance diagnosis and treatment.

Disease progression: identification of high-risk groups and individuals for periodontitis

AIMS

While the role of bacteria in the initiation of periodontitis is primary, a range of host-related factors influence the onset, clinical presentation and rate of progression of disease. The objectives of this review are (1) to present evidence for individual predictive factors associated with a patient's susceptibility to progression of periodontitis and (2) to describe the use of prognostic models aimed at identifying high-risk groups and individuals in a clinical setting.

METHODS

Relevant publications in the English language were identified after Medline and PubMed database searches. Because of a paucity of longitudinal studies investigating factors including clinical, demographic, environmental, behavioural, psychosocial, genetic, systemic and microbiologic parameters to identify individuals at risk for disease progression, some association studies were also included in this review.

FINDINGS AND CONCLUSIONS

Cigarette smoking is a strong predictor of progressive periodontitis, the effect of which is dose related. High levels of specific bacteria have been predictive of progressive periodontitis in some studies but not all. Diabetics with poor glycaemic control have an increased risk for progression of periodontitis. The evidence for the effect of a number of putative factors including interleukin-1 genotype, osteoporosis and psychosocial factors is inconclusive and requires further investigation in prospective longitudinal studies. Specific and sensitive diagnostic tests for the identification of individuals susceptible to disease progression are not yet a reality. While factors assessed independently may not be valuable in predicting risk of future attachment loss, the combination of factors in a multifactorial model may be useful in identifying individuals at risk for disease progression. A number of multifactorial models for risk assessment, at a subject level have been developed but require validation in prospective longitudinal studies.

Cementodentinal Tear: A Case Report With 7-Year Follow-Up

BACKGROUND

Cemental tears are an uncommon form of root fracture that can lead to rapid localized attachment loss. Typically, the separation of the fragment occurs at the cementodentinal junction. In this report, we present a case of periodontal involvement associated with a cemental tear-like fragment that proved to be a cementodentinal tear. We also review the literature on the clinical presentation of cemental tear associated periodontal lesions.

METHODS

A 52-year-old male presented with acute pain on the maxillary right second premolar. Clinically, probing depth of 7 mm and inflammation were noted on the distal aspect of tooth #4. Radiographic examination revealed separation of cervical root structure on the distal aspect of the tooth, involving two-thirds of the root length. The root fragment was removed, and the localized defect was treated by open flap debridement along with scaling and root planing. The patient was then placed on a regular periodontal maintenance schedule.

RESULTS

A postoperative probing depth of 2 mm with 1 mm recession was recorded at 3 months, and maintained for 7 years. Histological examination indicated that the detached root fragment contained dentin with overlying acellular cementum and associated periodontal ligament tissue. The fragment was estimated to represent as much as 20% of the total root surface area.

CONCLUSION

Moderate to severe periodontal attachment loss associated with cemental or cementodentinal tears, even ones constituting a significant portion of the root surface, can be successfully treated with conventional periodontal surgical procedures and maintained long term with a proper maintenance regimen.

Detection of localized tooth-related factors that predispose to periodontal infections

The primary goal of periodontal therapy is to produce an environment that is conducive to oral health. This is achieved by eliminating the subgingival infection and implementing supragingival plaque control measures designed to prevent the re-colonization of the sulcus. Local etiologic factors, as described above, my prevent the removal of subgingival plaque, and may even contribute to destruction of the periodontal tissues. Thus, it is crucial to be able to recognize and, when possible, eliminate any plaque-retentive factor that could contribute to disease progression. Iatrogenic factors such as subgingival margins, restorative overhangs, overcontoured restorations and unpolished surfaces can be altered. Similarly, cervical enamel projections, enamel pearls and, in certain instances, palatal grooves can be removed or recontoured to enable the patient to access the area for good plaque control. There are some things that we cannot alter. Anatomic anomalies, particularly in posterior teeth, cannot be changed. However, awareness of potential anatomic variations and early detection of them may be able to prevent future attachment loss.

Tooth-related issues

Several conditions exist around teeth that may predispose the periodontium to disease. These situations may occur as a result of the condition or position of teeth or as a result of tooth treatment. In certain cases these tooth-related factors may contribute to the initiation of periodontal disease. While the etiology of periodontal disease is bacterial, factors that enhance bacterial accumulation or allow the ingress of bacteria into the periodontium should be considered in the classification and diagnosis of periodontal diseases. This is because many times these tooth-related issues can cause site-specific problems that require treatment in an otherwise intact periodontium. Several factors related to tooth/root anatomy, restorative, and endodontic considerations have been associated with gingival inflammation, attachment loss, and bone loss. These factors will be reviewed as they relate to their potential to promote damage to the periodontium.

Retention of adhesive cement on the tooth surface after crown cementation

STATEMENT OF PROBLEM

Adhesive cements increase crown retention, but it is unknown if traces of cement remain undetected on the tooth surface after clinical removal of excess cement, which could exacerbate plaque retention.

PURPOSE

This study measured the surface area, volume, mean depth, and maximum depth of a resin composite and a compomer luting cement left adherent on the tooth surface after removal of excess cement, as judged clinically.

METHODS AND MATERIAL

Four groups of specimens (n = 48) were prepared for full coverage crowns: group AC bonding alloy with chamfer finish line, group G gold alloy with chamfer finish line, group PC porcelain with a chamfer finish line, and group PS porcelain with a shoulder finish line. Two profiles of the mesial and distal surfaces of the teeth were carried out: (1) tooth with crown seated but not cemented and (2) tooth with the crown cemented in place. Two cements and 2 methods of cement removal were studied.

RESULTS

A 4-way analysis of variance for cement, crown type, method of removal, and tooth surface morphology showed that significantly greater volumes and mean depth, but not surface areas, of resin composite cement remained adherent than compomer cement (P<.05). Among crown types, significant differences were found for cement volume (group G>AC, G>PC, G>PS), cement surface area (group AC>PC, G>PC, G>PS), and maximum cement depth (group G>AC). There was no significant difference between the 2 methods of cement removal. Significantly larger surface areas and maximum depths of cement were retained on the anatomically grooved mesial surface of the maxillary first premolars than on the ungrooved distal surface.

CONCLUSION

Subclinical cement retention occurred after crown cementation, which was influenced by cement, crown type, and tooth surface morphology but not method of cement removal.

The influence of anatomic and iatrogenic root surface characteristics on bacterial colonization and periodontal destruction: a review

PERIODONTITIS IS A MULTIFACTORIAL infectious disease affecting primarily a subset of subjects and a subset of sites. Recent microbiological data have acknowledged that before disease progression can occur, a susceptible host and site are required, in addition to the presence of pathogenic bacteria. This review discusses factors affecting periodontal disease progression and focuses in particular on the influence of anatomic and iatrogenic root surface characteristics. Retrospective studies clearly suggest a strong association between anatomic aberrations and periodontal attachment loss. Cemental tear seems to have the potential to initiate an aseptic, rapid, site-specific periodontal breakdown in a non-infected environment, illustrating the complexity of the attachment loss process. Recent experimental findings, furthermore, demonstrate a significant influence of root surface instrumentation roughness upon subgingival plaque formation and gingival tissue reactions, as well as a significant and positive relationship between subgingival plaque accumulation and inflammatory cell mobilization. These results indicate that subgingivally located irregularities may form stagnant sites or ecological niches which favor both retention and growth of organisms. Such events in addition to the progressive inflammatory changes may critically influence the subgingival environment by turning a stable site into an unstable or active periodontitis site. Thus, local anatomic and iatrogenic root surface characteristics may have a more profound effect on gingival health than previously assumed, particularly on a site level.

Prognosis versus actual outcome. II. The effectiveness of clinical parameters in developing an accurate prognosis

The assignment of prognosis is one of the most important functions undertaken in clinical practice, yet there is little evidence to support the current decision-making process which is based on an outdated model of disease etiology and progression. This study evaluated 100 treated periodontal patients (2,484 teeth) under maintenance care for 5 years, with 38 of these patients followed for 8 years, to determine the relationship of assigned prognoses to the clinical criteria commonly used in the development of prognosis. The method of generalized estimating equations (GEE) for correlated data was utilized to determine the relationship of each clinical factor to the assignment of initial prognosis, improvement in prognosis at 5 years, and worsening in prognosis at 5 years. A multiple linear regression model was constructed for predicting initial prognosis based on initial clinical data. Increased probing depth, more severe furcation involvement, greater mobility, unsatisfactory crown-to-root ratio, malpositioned teeth, and teeth used as fixed abutments resulted in worse initial prognoses. The coefficients from this model were able to predict accurately the 5-year and 8-year prognoses 81% of the time. When teeth with "good" prognoses were excluded, the predictive accuracy dropped approximately 50%. Multiple logistic regression models indicated that improvement in prognoses and worsening in prognoses were both strongly associated with initial probing depth, initial furcation involvement, initial tooth malposition, and smoking when adjusted for initial prognosis. In addition, good hygiene was found to increase the probability of improvement in prognosis while initial mobility was found to decrease the likelihood of improvement in prognosis. Neither of these factors was found to be significant in worsening of prognosis. Smoking decreased the likelihood of improvement by 60% and doubled the likelihood of worsening in prognosis at 5 years. The results of this study indicate that some clinical factors used in the assignment of prognoses are clearly associated with changes in clinical condition over time. The data also demonstrated that the traditional approach for assigning prognoses is ineffective for teeth with an initial prognosis of less than good. Since most periodontally involved teeth are compromised, further work should include the development of a more effective method for assigning prognoses that is based on clear, objective clinical criteria.

Cemental tear: a risk factor in periodontal attachment loss

The objective of this retrospective study was to evaluate the influence of cemental tear as a risk factor in periodontal attachment loss. Seventeen extracted, single-rooted teeth showing loss of attachment and having one cemental tear surface and one opposite intact surface were examined. The teeth were stained in 0.1% toluidine blue to visualize attached periodontal ligament remnants and examined in a light microscope under incident light. On each tooth, loss of attachment was measured along the long axis of the root from the cemento-enamel junction to the most coronal level of the periodontal ligament on intact as well as on defect surfaces. Cemental tear surfaces demonstrated a significantly greater loss of attachment than opposite intact surfaces (P < 0.0001). In one specimen, the cemental tear fragment was partially attached to the root after the extraction procedure. This specimen was processed for light microscopy to determine the location of the cemental tear fracture. Histological examination clearly revealed that the split between the root and the fragment had occurred along the cemento-dentinal border. The results indicate that cemental tear should be considered as a possible etiologic entity in localized rapid periodontal breakdown.

Influence of tooth instrumentation roughness on gingival tissue reactions

Histological studies have demonstrated a relationship between the amount of subgingival plaque and the magnitude and extension of gingival tissue reactions. The objective of the present study was to evaluate inflammatory reactions in the gingival tissues facing plaque accumulation at a diamond and curet-instrumented root surfaces. Experimental, deep periodontal defects were established at buccal surfaces of mandibular and maxillary canine teeth in 5 beagle dogs. The root surfaces were instrumented by a flame-shaped, fine-grained. rotating diamond point, or by a sharp curet. Next, the dogs were fed a plaque-inducing diet for 70 days. The animals were then sacrificed, and tissue blocks of the experimental sites including teeth, alveolar bone, and gingival tissues were secured. The gingival soft tissue was processed for histomorphometric analyses at 3 levels. Epithelium and connective tissue area measurements showed no differences between the two instrumentations. Junctional epithelium (JE) cell point counts exhibited a higher proportion of inflammatory cells (IC)in specimens facing diamond compared to curet-instrumented defects. A higher proportion of IC was present within the coronal compared to the apical aspect of the JE for both instrumentations (P < 0.05). A significant difference in IC density between instrumentations was detected for non-infiltrated (P < 0.05), as well as for infiltrated (P < 0.01) connective tissue. The infiltrated connective tissue (ICT) inflammatory cell density was significantly (P < 0.01) and positively correlated to the JE inflammatory cell density (r = 0.75), and to area measurements of ICT (r = 0.55). The overall results demonstrate that the character of subgingival root instrumentations significantly affects gingival inflammatory reactions, most likely by influencing subgingival plaque formation.

Cervical cemental tears in older patients with adult periodontitis. Case reports

This communication reports 5 cases of cervical and 1 apical cemental tears. The diagnosis of the cervical tears was made by a characteristic feature which presented radiographically as a prickle-like body. The fragment of cementum could be detached by root planing or during periodontal surgery and uneventful healing was obtained following these procedures. The process of aging in addition to continuous occlusal strain may lead to this phenomenon. Cervical cemental tear may be one of the contributing factors in the progress of adult periodontitis.