Periodontal status of teeth with crown–root fractures: results two years after adhesive fragment reattachment

Aim: This series of case reports evaluated the impact of adhesive crown–root fragment reattachment in periodontally healthy teeth suffering from crown–root fractures on various parameters of periodontal health over a time course of 2 years.
Material and Methods: A total of 20 teeth with crown–root fractures in 18 periodontally healthy subjects were evaluated. After open-flap access, crown–root fragments were adhesively reattached to the root stub. In all cases, the vertical difference between the alveolar bone crest and the fracture line was 1 mm, i.e. violating the biological width. Subsequently, clinical attachment level (CAL), probing pocket depth (PPD), bleeding on probing (BoP) and gingival index (GI) scores were recorded at 6, 12 and 24 months postoperatively for the restored teeth as well as plaque index (PlI) and periodontal screening index (PSI) values for the whole dentition.
Results: Two years after therapy, recorded CAL, PPD, BoP, GI, PlI and PSI scores revealed healthy periodontal conditions in 18 out of 20 treated teeth. Two teeth had suffered again from fragment fracture due to new traumata.
Conclusions: Adhesive fragment reattachment in periodontally healthy teeth affected by crown–root fractures had no detrimental impact on periodontal health over a time course of 2 years.     

Subgingival debridement of root surfaces with a micro-brush: macroscopic and ultrastructural assessment

AIM: The aim of this study was to assess the use of a micro-brush to remove plaque deposits from subgingival, periodontally involved root surfaces in vivo. METHODS: 30 periodontally involved teeth requiring extraction for periodontal or prosthetic reasons in 26 adult patients were utilised. For inclusion, teeth had to display at least 30% bone loss radiographically. Following the establishment of local anaesthesia, grooves were cut on the proximal root surface adjacent to the gingival margin at the line angles. For each tooth, 1 proximal root surface was rubbed with the micro-brush for 2 min to the depth of the pocket whilst the other root surface acted as an undebrided control. The teeth were then extracted, rinsed in 0.85% NaCl, stained with 2% erythrosine solution and photographed. The amount of erythrosine staining on each subgingival, periodontally involved root surface was assessed by tracing the areas of stain on a colour photograph and scanning the tracings into a computerised image tracing program. RESULTS: Results were expressed as the % of the periodontally involved root-surface area that exhibited staining. Stained areas were further examined with the scanning electron microscope (SEM). The undebrided root surfaces each displayed 100% staining. The debrided surfaces (with probing pocket depths of 4-10 mm) displayed mean staining of 16.1% (SD +/-7.1%) of the proximal surface area. SEM assessment showed that undebrided root surfaces were covered with thick deposits of bacteria. On debrided surfaces, stain-free areas were free of plaque whilst areas of faint staining exhibited either no plaque, calculus deposits or scanty, isolated islands of bacteria. Bacteria had been partially removed from the surface of calculus in some areas. CONCLUSIONS: The findings indicate that subgingival debridement with a micro-brush is effective in removing plaque deposits from periodontally involved root surfaces.     

PRESENCE OF BACTERIA IN DENTINAL TUBULES

This study demonstrated that a significant number of bacteria is present in the radicular dentinal tubules of periodontally diseased human teeth. Ten periodontally diseased teeth were prepared and stained by Brown and Brenn technique for histological examination. Bacteria were detected in all teeth. It is suggested that bacteria may invade dentinal tubules exposed to periodontal pocket and are very hard to be eliminated by conventional mechanical and chemical periodontal therapy. Contaminated dentinal tubules of periodontally diseased teeth can thus act as active bacterial reservoirs to promote recolonization of mechanically treated root surfaces, which could interfere with the periodontal healing and progression of the disease.     

Retention of hopeless teeth: the effect on the adjacent proximal bone following periodontal surgery

BACKGROUND: Clinical wisdom often suggests that retention of periodontally hopeless teeth may accelerate the destruction of the adjacent periodontium. The purpose of this study was to examine the effect of retaining hopeless teeth on the adjacent alveolar bone following periodontal surgery. METHODS: A retrospective study was conducted based on intraoral radiographs. Teeth were considered hopeless if they had lost > or =70% bone height at either of the proximal surfaces. The minimal follow-up period after surgery was 24 months. All subjects completed periodontal therapy, including scaling and root planing (SRP), and periodontal surgery at these sites. Ninety-three subjects with 110 hopeless teeth were included in this study. Cases were sorted into two groups: retained, which included 57 hopeless teeth (50 subjects) that were maintained; and extracted, which included 53 hopeless teeth (43 subjects) that were removed at surgery. All radiographs were digitized, and measurements of radiographic bone distance (RBD) were made using computerized software. RESULTS: Mean follow-up was 4.40 +/- 0.23 years. For the retained hopeless teeth, there was a mean bone gain of 0.82 mm from baseline (7.18 +/- 0.35 mm) to the final examination (6.45 +/- 0.41 mm; P = 0.0061). Likewise, the postoperative percentage of RBD of the retained hopeless teeth showed a statistically significant improvement from baseline (57.46% +/- 1.5%) to the final examination (52.32% +/- 2.03%; P = 0.0032). Teeth adjacent to a hopeless tooth had a slight radiographic bone gain postoperatively, which was greater in the extracted group. However, it was significant only for the distal neighboring teeth (1.50% versus 11.36%, respectively; P = 0.0119). CONCLUSION: Long-term preservation of hopeless teeth following periodontal surgery is an attainable goal with no detrimental effect on the adjacent proximal teeth.     

Intentional replantation for periodontally involved hopeless teeth

Abstract –  The aim of this study was to evaluate the clinical and radiographic results of intentional replantation of periodontally involved teeth after conditioning of root surfaces with tetracycline–HCl. Thirteen patients (seven female, six male; age range: 35–52 years) with 15 periodontally involved hopeless teeth were included in this study. During the replantation procedure, the affected teeth were gently extracted, then the granulation tissues, calculus, remaining periodontal ligament and necrotic cementum on the root surfaces were removed. Tetracycline–HCl, at a concentration of 100 mg ml⁻¹, was applied for 5 min to the root surfaces. The teeth were then replaced into the socket and splinted. Patients were clinically and radiographically evaluated at baseline (time of surgery) and 6 months after the surgery. The following measurements were recorded: probing depth (PD), gingival recession (R), the amount of bone loss (BL) and bone gain (BG). Results indicated a reduction in PD and in the amount of bone loss and healthy gingiva. Mean PD was decreased from 5.25 to 2.36 mm, gingival recession was increased from 3.73 to 4.0 mm, and BL was reduced from 73.20 to 56.86%. At the end of 6 months, no root resorption or ankylosis was observed radiographically. Even during the short period of evaluation, it may be suggested that intentional replantation can be an alternative approach to extraction in cases where advanced periodontal destruction is present and no other treatments could be considered.     

Presence of an enamel matrix protein derivative on human teeth following periodontal surgery

An enamel matrix protein derivative (EMD) has been successfully employed to restore fully functional periodontal ligament, cementum, and alveolar bone in patients with severe attachment loss. When applied to denuded root surfaces, EMD is believed to assemble into a matrix that locally stimulates regenerative responses in the surrounding tissues. Since wound healing and induction of regeneration are biological processes typically running from weeks to months after treatment, the EMD matrix must be present on the root surface over a biologically significant time period to be effective. So far, no studies have been done in humans on the persistence of EMD on the treated root surface. The aim of the present study was to investigate the persistence of the EMD-based matrix on periodontally involved human teeth treated surgically with EMD. Sixteen patients with one intrabony defect each around teeth scheduled for extraction due to advanced periodontitis were treated by means of access flap surgery with and without application of EMD. At 1, 2, 3, and 4 weeks postsurgery, the teeth were removed and processed for histology and immunohistochemistry. The slides were stained using a rabbit anti-enamel-matrix-derivative (anti-EMD) antibody and goat-antirabbit secondary antibodies labeled with horseradish peroxidase (HRP). Immunohistochemical evaluation demonstrated the presence of EMD on all test root surfaces during the entire observation period of 4 weeks. No EMD was detected on any of the control roots. The results demonstrate for the first time in humans that EMD is present on treated root surfaces for up to 4 weeks following periodontal surgery.     

Retained "hopeless" teeth. Effects on the proximal periodontium of adjacent teeth

The retention of teeth diagnosed as periodontally "hopeless" may accelerate the destruction of the adjacent proximal periodontium. Studies determining the influence these teeth have on the health status of adjacent teeth appear nonexistent. It was the intent of this retrospective study to assess the status of the periodontium in adjacent teeth proximal to the periodontium of "hopeless" teeth. We evaluated 17 teeth, each being mesially adjacent to one "hopeless" tooth, in 17 subjects treated for periodontal disease. In each case, the "hopeless" and the adjacent teeth received the same treatment. Probing depths (P-D), radiographic alveolar bone level (R-BL) and the width of the periodontal ligament space (W-PL) were measured for both the adjacent interproximal and the nonadjacent interproximal surface for each hopeless tooth. At both pretherapy and posttherapy, there were no significant differences for any of the variables (P-D, R-BL and W-PL) for the adjacent interproximal surfaces with the nonadjacent interproximal surfaces. However, there was a significant reduction in the mean probing depth for the adjacent interproximal surfaces, pretherapy to posttherapy. No other significant changes were found in any of the other variables for either the adjacent or nonadjacent interproximal surfaces. These data suggest that teeth considered periodontally "hopeless" and retained have no effect on the proximal periodontium of adjacent teeth prior to and following therapy.     

Fine structure of new connective tissue attachment following acid treatment of experimental furcation pockets in dogs

Periodontal furcation pockets were created in mandibular premolar teeth of three beagles and subsequently treated by reconstructive procedures including flap surgery, root planing and application of citric acid. Block biopsies removed after 1, 2, 3 and 6 weeks showed new attachment of connective tissue to the periodontally involved root surface. This was established by progressive interdigitation of new collagen fibrils and the acid-exposed fibrils of the dentin matrix along the root planed surface as well as within the orifice of dentinal tubules. The results supplement those of a previous study (Ririe, Crigger & Selvig 1980) and show that attachment of soft connective tissue to a root planed and acid-conditioned dentin surface can be achieved by the same mechanism irrespective of whether the root surface has been surgically denuded or has been exposed to the environment of an experimental periodontal pocket.     

Er,Cr:YSGG激光照射后牙周病牙根面的形态学研究和钙磷比率分析

目的 观察Er,Cr:YSGG激光照射后牙周病牙根面的形态学变化及主要元素钙、磷的改变。方法 收集中、老年人离体牙周病牙18颗、健康阻生第三磨牙6颗。对18颗牙周 病患牙根面进行平整后,随机选取12颗作激光照射研究;其余6颗作酸处理研究;6颗第三磨牙作健康对照。扫描电镜下观察不同根面处理方式导致的根面形态变化,用色谱分析仪分析各组根面钙磷比率（Ca/P）,并进行统计学比较。结果 激光照射组可有效去除玷污层,得到粗糙度较均匀、洁净的根面。酸处理组去除根面玷污层能力较强,但电镜观察两组根面形态有差异。两组均未发现熔融、炭化、裂纹及牙本质暴露。色谱分析仪分析结果显示激光照射组与酸处理组根面钙磷比率无明显差异（P>0.05）。结论 Er,Cr:YSGG激光照射根面平整后的牙周病牙根面可有效去除玷污层及表层病变牙骨质,具有潜在的应用 价值。     

Endodontic pathogens in periodontal disease augmentation

Abstract. Periapical pathology indicating endodontic infection, when present in periodontitis-affected teeth, has recently been shown to be correlated to marginal periodontal breakdown. This has been associated with patency of dentinal tubules in the tooth cervix, an area normally devoid of cementum following periodontal therapy. These studies are, however hampered by that only circumstantial evidence such as presence of periapical destruction have been applied as criteria of endodontic infection. The aim of the present investigation was to assess the effects of endodontic pathogens on marginal periodontal wound healing on root surfaces devoid of cementum but surrounded by healthy periodontal membrane. Significant differences between infected and non-infected teeth were found with respect to pathological pocket and connective tissue: The experimental defects were covered by approximately 20% more pocket epithelium in infected teeth while defects in non-Infected teeth showed approximately 10% more connective tissue coverage. It was concluded, that an intra-canal infection of endodontic pathogens stimulates epitelial downgrowth along denuded dentin surfaces with marginal communication. Extrapolated to the clinical situation, endodontic infections in periodontitis-prone patients may augment periodontitis propagation.     

Healing following reimplantation of teeth subjected to root planing and citric acid treatment

The aim of the present study was to examine the effect of citric acid treatment on periodontal healing around teeth which were extracted, root planed and then reimplanted. Maxillary incisors and mandibular incisors, premolars and molars of 5 monkeys were used. The teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted and immediately reimplanted into their own sockets. In a 2nd group, the teeth were extracted, root planed to a level corresponding to 50-75% of the root length and then reimplanted. In the 3rd group, periodontal breakdown extending to 50-75% of the root length was first induced by placing orthodontic elastic ligatures around the teeth. They were then extracted and root planed and transplanted into the sockets of the contralateral, periodontally healthy teeth which had just been extracted. Half the number of the teeth of groups 2 and 3 were treated with citric acid before reimplantation or transplantation. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. With the exception of a limited coronal regrowth of new cementum in the apical part of the planed portion of a few roots, connective tissue attachment failed to reform on most root surfaces deprived of their periodontal ligament tissue. Healing was most frequently characterized by root resorption and ankylosis. These were the most predominant features of healing both on root surfaces which had been deprived of the ligament tissue by mechanical means or during a course of experimentally-induced periodontal disease, and occurred in citric acid as well as non-citric acid treated roots. The findings imply that the result of healing following tooth reimplantation or transplantation is determined by the type of cells that repopulate the wound area adjacent to the denuded root surface.     

Periodontal conditions of teeth autogenously transplanted by a two-stage technique

Inflammatory reactions of the marginal periodontal tissues and loss of attachment could partly account for the often occurring rejection of autogenously transplanted mature teeth. The periodontal conditions of transplanted teeth were investigated from 1 month up to 5 years postoperatively. The parameters plaque, bleeding on probing to the bottom of the pocket, probing pocket depth (PPD), gingival recession and probing attachment loss were analysed by multiple regression analysis. No significant difference was found between transplanted and control teeth in bleeding on probing the bottom of the pockets up to 5 years postoperatively with the exception of increased bleeding on probing of the transplanted teeth at the 1-month postsurgery examination. No significant difference of the mean probing depth between transplanted teeth and control teeth was found at the mesio- and distobuccal surfaces. The transplanted teeth at the buccal surface showed increase of the mean pocket depth during the observation period. Increased mean probing depth without progression over time was found at the transplanted teeth compared to the controls at the distolingual, lingual and mesiolingual surfaces. A small mean gingival recession at the transplants was observed. Loss of attachment was recorded at 13% of the surfaces. Totally 50% of the transplants showed loss of attachment and 5% were removed because of extensive attachment loss. On 13% of the transplanted teeth with loss of attachment, root resorption was also found.     

Radiographic analysis of normal periodontal tissues]

The present study was designed to investigate the roentgenographic manifestations of clinically healthy periodontal tissues in two sample groups. One group consisted of dry skulls of 4 young subjects who had been reportedly healthy during lifetime. The other group included 31 healthy students aged 16-25 years. A set of 7 standardized bite-wing radiographs were taken in each mouth. 4x magnified photos were developed for measurement and assessment. The interproximal alveolar bone level (BC-CEJ distance) was determined by measuring the distance from the lowest point of alveolar bone crest to the imaginary line connecting the two CEJs of the adjacent teeth. Both the radiographic signs of lamina dura and of the PDL space were graded to compose Lamina Dura Index (LDI) and periodontal ligament space index (PDLI). It is found that the average distance of BC to CEJ in periodontally healthy subjects is from 0.62 to 1.67 mm. Radiographic signs such as disappearance of lamina dura on the alveolar bone crest, wedge-shaped widening of the periodontal ligament space at the bone crest are not uncommonly seen in clinically healthy periodontal sites. The frequency of these signs on teeth with normal periodontium and their distribution on tooth sites were also presented and discussed.     

Connective tissue regeneration to periodontally diseased teeth

A study was made to investigate the biological principle of new attachment of connective tissue to periodontally diseased root surfaces utilizing the previous finding that topical application of citric acid to the affected area may stimulate periodontal regeneration. Reconstructive surgery was performed on ten surfaces of nine teeth involved in advanced chronic periodontal disease. A muco-periosteal flap was raised and the apical extent of existing subgingival calculus was demarcated by a notch made through the calculus and into the root. Following thorough instrumentation, a saturated solution of citric acid was applied to the root surface for five minutes and the flap repositioned and sutured. Four months later the teeth with attached periodontal tissues were removed and processed for histological analysis. Connective tissue regeneration characterized by deposition of new cementum, and more coronally, by tightly apposed soft connective tissue had occurred in all specimens. The junctional epithelium ended 1.2–2.6 mm coronal to the apical border of the notch in the various specimens. The results demonstrate that regeneration of periodontal tissues to a root surface that has become denuded as a result of chronic, destructive periodontal disease and that has been covered by calculus is, in fact, a biological possibility. This study does not establish whether or not acid conditioning of the root surface is a prerequisite for new attachment.     

Autologous tooth transplantation to replace molars lost in patients with juvenile periodontitis

A method is described to replace perodontally destroyed first molars in patients with juvenile periodontitis by auto-transplantation of third molars. Fifteen molars which had been extracted due to periodontal destruction were replaced by autologous third molars with incomplete root formation. The patients were then observed for a period up to 7 years. In all cases complete regeneration of the alveolar bone took place and radiographically a normal periodontal membrane was extablished. All of the transplanted teeth continued their root formation and there was no radiographic evidence for root resorption, ankylosis or necrosis of the pulp. None of the transplanted teeth displayed pocket depths over 3 mm and no abnormal mobility was detectable.     

Retained "hopeless" teeth: lack of effect periodontally-treated teeth have on the proximal periodontium of adjacent teeth 8-years later.

We previously reported the lack of effect periodontally-treated teeth prognosed "hopeless" and retained for 3.4 +/- 1.5 years have on the proximal periodontium of adjacent teeth. We now report our findings for the same group of subjects following 8.4 +/- 0.7 years of "hopeless" tooth retention. Of the 17 "hopeless" and adjacent teeth originally measured in 17 subjects, 14 of the subjects were still available for re-evaluation. Measures used to assess the periodontium of proximal surfaces of adjacent teeth included pocket depths (PD), radiographic alveolar bone level (R-BL), and periodontal ligament space width (W-PL). Treatment for the subjects consisted of surgical therapy (N = 15) and scaling and root planing (N = 2). Of the 14 subjects re-examined, 2 were eliminated due to loss of adjacent tooth reference points and 2 due to extraction of the "hopeless" tooth (N = 10). Differences in measurements (i.e., nonadjacent to "hopeless" tooth value minus adjacent to "hopeless" tooth value) were analyzed using a repeated measures ANOVA. There were no significant differences for PD (P = 0.20), R-BL (P = 0.29), or W-PL (P = 0.16). These data confirm our original findings that retained periodontally "hopeless" teeth do not significantly affect the proximal periodontium of adjacent teeth following therapy.     

Long-term periodontal status of teeth moved into extraction sites

The present study was undertaken to assess the long-term periodontal status adjacent to teeth that had been moved orthodontically into extraction sites. Twelve persons with a mean age of 29.2 +/- 5.7 (SD) years, who had completed orthodontic therapy at least 10 years previously, were examined. The orthodontic treatment had included bilateral premolar extraction in only the maxilla. Interproximal tooth surfaces in the maxilla adjacent to the extraction sites (study group) were compared to corresponding tooth surfaces in the mandible (control group) with respect to plaque, visual inflammation, bleeding after probing, pocket depth, gingival recession, loss of connective tissue attachment, radiographic bone height, and root resorption. Statistical comparisons were made via analyses of variance and t tests. There were no differences between the groups for any clinical parameter except the presence of less visual inflammation in study subjects. Radiographically, there were no differences in crestal alveolar bone levels measured from the cementoenamel junction. Bone height evaluation by the Bjorn method showed less alveolar support in the study group. However, this was due to the influence of root resorption rather than an effect on crestal height. It was concluded that orthodontic movement of teeth into extraction sites had been without detrimental effect upon the adjacent periodontal status.     

Histo-pathology of the regenerating process in the tissue around the periodontally diseased teeth of beagle dogs. Clinical and histological analysis following flap surgery

The regenerating process in tissue around periodontally diseased teeth (PDTs) and non-diseased teeth (NDTs) was studied with clinical and histological analysis following flap surgery. PDTs were prepared in the premolars of 7 beagle dogs by which surgically denuding the root surfaces by removing the alveolar bone. The denuded sites were covered with gutta-percha plates and gingival epithelial tissues and exposed to the oral environment for 4 weeks. Then flap surgery was performed on the PDTs. As control sites, the root surfaces of the NDTs were denuded by removing the alveolar bone at the time of flap surgery. The root surfaces of the PDTs and NDTs were planed with curette scalers at one root site but not at the other site. Clinical and histopathological findings were evaluated at fixed intervals for 32 weeks after surgery. Results of observation were as follows. 1. In the clinical evaluations, the gingival inflammation index, probing depth and attachment level were improved in the root planing (PR) group of both the PDTs and the NDTs, but in the non RP group of PDTs there was no improvement. 2. In the histologic observation, the position of the gingival margin, length of regenerated junctional epithelium, depth of gingival sulcus and the level of connective tissue attachment in the RP groups recovered in both the PDTs and the NDTs but not in the non RP groups.     

Bacterial invasion in root cementum and radicular dentin of periodontally diseased teeth in humans. A reservoir of periodontopathic bacteria

In this study the viability and the distribution of bacteria within the radicular dentin and pulp of periodontally diseased caries-free teeth were studied. Healthy teeth served as controls. Samples were obtained from the pulp tissue and from the radicular dentin. Dentin samples were taken from the interdental surfaces in the subgingival area. Starting from the pulpal side, three to five successive dentin layers of approximately 1 mm thickness were sampled. The samples were processed and cultured using an anaerobic technique. Bacterial growth was detected in 87% of the periodontally diseased teeth. In 83% of the teeth, bacteria were present in at least one of the dentin layers. Fifty-nine percent of the diseased teeth, from which the pulp tissue was cultured, contained bacteria in the pulp samples. The mean bacterial concentrations in the pulp and dentin layers ranged from 1,399 to 16,537 colony-forming units (CFU) per mg of tissue. These concentrations were 259 to 7,190 times greater than concentrations found in healthy teeth. It is suggested that the roots of periodontally diseased teeth could act as bacterial reservoirs from which recolonization of mechanically treated root surfaces can occur, as well as infection of the dental pulp. These findings might change current concepts concerning root surface debridement in periodontal therapy.