Cementodentinal Tear Associated with a Periodontal- Endodontic Combined Lesion: A Case Report with a 14-Month Follow-up

This case report describes the diagnosis and multidisciplinary treatment of a clinically indiscoverable cementodentinal tear associated with a periodontal-endodontic combined lesion. The tear site was located at the palatal root surface of the maxillary left canine. Due to its position and concomitant periapical periodontitis, it was not noticed at the initial visit until a 3D CBCT examination was conducted. Through combined endodontic-periodontal therapy (which included root canal therapy, root debridement, and periodontal flap surgery), the tear fragment was removed, and the periapical lesion healed gradually. A histologic examination confirmed the definitive diagnosis of a cementodentinal tear. After 14 months, the periodontal and endodontic status of the maxillary left canine were stable. According to these results, CBCT examination and multidisciplinary cooperation seem to be effective and necessary for the diagnosis and treatment of such clinically indiscoverable cementodentinal/cemental tears.

Cemental Tears: A Report of Four Cases and Literature Review

PURPOSE

To present four different cases with a diagnosed cemental tear. The differences in aetiology, clinical diagnosis and treatment of cemental tears are described and discussed in order to provide guidance for clinical practice.

CASES

Four patients of different ages presented with gingival swelling and other different complaints. Clinically, localised deep periodontal pockets and inflammation were noted on affected aspects in four cases. Radiographic examination revealed a prickly or flakey structure and bone loss on the affected side of the involved tooth. Different treatments, such as extraction, traditional periodontal initial therapy, periodontal flap surgery, or no clinical intervention were given based on different extents of tooth mobility and bone loss. In the first two cases, teeth with cemental tear were extracted due to poor prognosis. In case 3, deep pockets recovered to a normal condition, while cemental tears on the distal aspect of tooth 21 had no abnormal sensation or clinical symptoms. In case 4, a periapical radiograph showed distal bone loss was interrupted, and the tooth also recovered normal mobility. Histopathological evaluation of the specimens with H&E staining all resulted in a definitive diagnosis of cemental/cementodentinal tears.

CONCLUSIONS

Cementodentinal or cemental tears are unique, localized, tooth-related factors associated with attachment loss. Aging, trauma and occlusal overload are the main aetiological factors. Early diagnosis and appropriate treatment will avoid unnecessary tooth extraction and result in a better prognosis. Detailed clinical and radiographic examinations as well as explorative surgery may help to make a diagnosis of cemental tears, but histopathological analysis is the only method for a definitive diagnosis.

Diagnosis and management of cemental tear: a case report

A 32-year-old man complained of swelling after an extraction in the vicinity of the left maxillary premolars. The occlusal surface of the first premolar showed no caries while the second premolar was covered with a crown. Radiographic examination revealed a thin radiolucent defect subgingivally below the cementodentinal junction on the distal aspect. During a review of medical history, the patient presented an extracted fragment that was sent for histopathological examination. A root canal was performed and the defect was closed with mineral trioxide aggregate followed by glass ionomer cement. Histopathology revealed the fragment to be a cemental tear, a condition associated typically with old age, trauma, and traumatic occlusion. Dentists should be aware of this rare entity as a differential diagnosis in cases involving noncarious odontogenic pain.

Understanding root resorption with diagnostic imaging

This article presents the clinical, radiographic and histopathologic features of various types of tooth root resorption. Tooth resorption may occur in a tooth internally or externally with distinctively different treatment approaches for each type of resorption. Given that proper diagnosis of the type of resorption is important, the use of cone beam computed tomography (CBCT) and conventional 2-D intraoral images in evaluation of resorptive lesions is discussed.

Microscopic evaluation of induced tooth movement after subluxation trauma: an experimental study in rats

OBJECTIVE

The objective of this study was to assess the histological alterations that occurred in the periodontal area of rat molars submitted to induced tooth movement (ITM) right after an intentional trauma (subluxation).

METHODS

Forty adult male Wistar rats (Rattus norvegicus albinus) were selected. The animals were divided into eight groups (n=5), according to the combination of variables: Group 1--control (neither trauma nor ITM); Group 2--ITM; Groups 3, 4, 5 and 6--dentoalveolar trauma groups corresponding, respectively, to 1, 3, 8 and 10 days after trauma; Groups 7 and 8 - the animals' molars were subjected to a 900 cN impact and, one and three days after the trauma event, tooth movement was induced. The rats' maxillary first molars were mesially moved during seven days with a closed coil (50 cN). After the experimental period of each group, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy.

RESULTS

In the animals of group 3, 4, 5 and 6, the histological alterations were not very significant. Consequently, the effect of induced tooth movement right after a subluxation event (groups 7 and 8) was very similar to those described for Group 2.

CONCLUSIONS

There was no difference in the quality of periodontal repair when ITM was applied to teeth that had suffered a subluxation trauma.

Effects of laser-aided circumferential supracrestal fiberotomy on root surfaces

OBJECTIVE

To evaluate and compare the effects of circumferential supracrestal fiberotomy in vivo (using diode, CO(2), and Er∶YAG lasers) on the morphology and chemical composition of the root surface.

MATERIALS AND METHODS

Forty healthy premolar teeth, intended for extraction for orthodontic reasons, were used in this study. Root surfaces were treated using different laser methods, as follows: (1) control; (2) Er∶YAG laser (2.94 µm, 100 mJ, 10 Hz); (3) diode laser (808 nm, 1.2 W, continuous wave); and (4) CO(2) laser (10.6 µm, 3 W, continuous wave). Subsequently, the teeth were removed and subjected to scanning electron microscopic (SEM) examination and energy dispersive x-ray (EDX) spectrometric analysis.

RESULTS

SEM analysis indicated that no thermal changes, including melting or carbonization, were observed following the lasing procedures. EDX analysis showed that the laser procedures resulted in similar mineral contents (weight % of calcium and phosphate) as compared to those in the control group.

CONCLUSION

Based on these findings, we concluded that laser-aided procedures, when used at appropriate laser settings, preserve the original morphology and chemical composition of cementum.

Treatment of severe localized periodontal destruction associated with a cemental tear: a case report and review of the literature

Cemental tears have been described as a fragment of cementum becoming detached from the root surface, which can lead to severe periodontal breakdown. A 50-year-old woman with no history of periodontal attachment loss had an asymptomatic, isolated deep pocket on the mesial aspect of tooth No. 14. The radiographic examination revealed a thin, chip-like radiopacity along the lateral aspect of tooth No. 14. Periodontal flap surgery revealed a cemental tear on the apical part of the tooth. The root fragment was removed and the intrabony lesion was treated with enamel matrix derivative. A clinical examination one year after surgery demonstrated resolution of the pocket. Radiographic examination revealed an apparent bone fill at the bottom and the mesial wall of the original defect. This case illustrates that severe attachment loss associated with a cemental tear can be treated successfully by removing the cemental fragment and applying enamel matrix derivative.

Persistent endodontic lesion due to complex cementodentinal tears in a maxillary central incisor—a case report

The cementodentinal tear is rarely detected by noninvasive procedures owing to its clinical picture simulating a root fracture or a periodontal or endodontic lesion. We present a case of complex cementodentinal tears in a 79-year-old woman who presented a repeated swelling at the labial mucosa of the left maxillary central incisor for 6 months. Periapical radiographs demonstrated a vertical radiolucent fracture line extending from the root apex along the mesial aspect of the root to near the middle portion of the root of the left maxillary central incisor. Because endodontic re-treatment failed to cure the disease, periapical surgery was performed, and 2 fractured U-shaped root fragments around the apical root surface were removed. Histologic examination showed that the 2 fractured root fragments were composed mainly of the dentin covered by a thin layer of the cementum and overlying periodontal ligament tissue, suggesting cementodentinal tears. A swelling recurred 8 months after the initial operation. Therefore, a second periapical surgery was performed. Although no obvious fracture line was observed around the root surface, the second surgery did not cure the disease, either. A persistent small swelling was noted at the alveolar mucosa of the affected tooth during the follow-up. We conclude that although a cementodentinal tear can be detected by a careful radiographic examination, its clinical outcome is not predictable by surgical removal only.

Root Resorption on Torqued Human Premolars Shown by Tartrate-Resistant Acid Phosphatase Histochemistry and Transmission Electron Microscopy

Objective: To identify clastic cells on the root surfaces of torqued human premolars.

Materials and Methods: A continuous force of 600 cNmm was applied to upper first premolars in patients 13–16 years of age by using a precise biomechanical model with superelastic wires (NiTi-SE). The 28 teeth in 14 patients were divided into five groups (control [nonmoved], and moved for either 1, 2, 3, or 4 weeks) and processed for tartrate-resistant acid phosphatase (TRAP) histochemistry and transmission electron microscopy.

Results: Mononuclear TRAP-positive cells appeared at 2 weeks, wheras large multinucleated TRAP-positive cells were numerous at 3 and 4 weeks. Ultrastructural examination revealed many clastic cells in contact with resorption lacunae. In addition, some cementoblast-like cells appeared secreting new cementum over previously resorbed lacunae.

Conclusions: In general, resorption lacunae and the number of clastic cells, which increased with the duration of the applied force, were found on the cementum surface at the pressure areas. Some signs of cementum repair were also noticed, even with the maintenance of the level of the force.

Cemental Tear: A Case Report of a Rare Root Fracture

A 79-yr-old female presented to the clinic for endodontic evaluation of an unresolved periodontal defect. The patient's dental history included extraction of tooth #30 with subsequent placement of two dental implants. The patient presented with a localized periodontal defect on the distal of tooth #29. Radiographic evaluation revealed a thin radiopacity and associated radiolucency along the entire lateral aspect of tooth #29. Periodontal surgery and biopsy resulted in a diagnosis of cemental tear. Cemental tears have been rarely reported in the endodontic literature. Case reports of cemental tears have been associated with age, trauma, and traumatic occlusion. With the increasing age of the dental population and longer retention of teeth, clinicians should be aware of this rare entity.

Cemental tear: a case report

AIM

To report a case of a cemental tear.

SUMMARY

A case is reported of a patient with a history of trauma, root canal treatment and retreatment procedures to eliminate recurring sinus tracts. An exploratory surgery, extraction, and biopsy resulted in a diagnosis of cemental tear.

KEY LEARNING POINTS

* The detachment of a fragment of cementum is described as a cemental tear. * Cemental tears have been reported in the periodontal literature associated with localized, rapid periodontal breakdown. Common causative factors are aging and traumatic occlusion but the exact aetiology is unknown. * Trauma may be considered as a potential aetiologic factor for cemental tears in addition to occlusal traumatism and aging.

Severe localized periodontal destruction associated with cervical cemental separation

Cemental separations and tears are secondary etiological factors that may lead to rapid periodontal destruction if the lesion communicates with the oral cavity and allows bacterial invasion. Although many cemental tears that occur on proximal surfaces can be diagnosed radiographically, separations on the facial or lingual surface that cannot be detected on radiographs may present a diagnostic dilemma. This article describes a case of lingual cemental separation on a maxillary incisor, with subsequent successful surgical correction utilizing an osseous graft.

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.

Comparative study of manual and ultrasonic instrumentation of cementum surfaces: influence of lateral pressure

The goal of periodontal treatments is to eliminate bacteria and their products without damaging cementum surfaces. Nonsurgical treatments are often limited by the inability of curettes to access the most apical zone of the pocket. While ultrasonic mini-inserts have been used for nearly 10 years now, their effect on dental tissues has not been tested. The purpose of the present study was to compare a new series of mini-inserts to Gracey curettes, which are the reference in nonsurgical treatments. Two experienced periodontists conducted root treatments on teeth destined for extraction using regular clinical criteria. One face of each root was instrumented using a Gracey curette, and the opposite face was instrumented using an ultrasonic mini-insert. After the instrumentation procedure, the teeth were prepared for examination by secondary electron (topographic features) and backscattered electron (organic and mineral composition) microscopy. Differences in surface composition between teeth treated by the two periodontists were noted and were related to the lateral pressure exerted. Calculus removal was less effective when strong lateral pressure was exerted using the ultrasonic mini-inserts, while more cementum was removed and more scratching occurred with both manual and ultrasonic instruments. In all cases, the ultrasonic mini-inserts allowed greater apical access. The new ultrasonic mini-inserts were as effective as manual curettes in eliminating plaque and calculus. The shape of the mini-inserts made them more effective in apical zones. The amount of damage to the cementum depended on the lateral pressure exerted by the periodontist.

Atypical localized deep pocket due to a cemental tear: case report

A 71-year old patient with a history of minimal periodontal attachment loss presented with an asymptomatic, non-bleeding, isolated deep pocket on the mesio-facial of a central incisor. Such localized, deep pockets are most frequently associated with a root fracture or an abscess, but in this case an atypical ledge-like projection determined to be a cemental tear was detected at the base of the 6 mm pocket. Periodontal flap surgery revealed a partial detachment of the cementum. Uneventful resolution of the pocket was achieved following root planing to remove the cemental fragment and placement of a bone graft and resorbable membrane. This article reviews the nature, predisposing factors, causes, clinical significance, and treatment of cemental tears.

Efficacy of subgingival calculus removal with Er:YAG laser compared to mechanical debridement: an in situ study

OBJECTIVES

The aim of the present study was to compare the effectiveness of subgingival calculus removal from periodontally involved root surfaces with an Er:YAG laser compared to hand instrumentation in situ.

METHODS

The mesial and distal surfaces of 30 single-rooted teeth with untreated periodontitis were treated either by hand instrumentation (scaling and root planing (SRP)) or by Er:YAG laser irradiation with the aim of achieving a calculus-free root surface. Subgingival plaque samples were obtained before and immediately after treatment for microbiological evaluation by culture and DNA probe analysis. The teeth were extracted and the residual calculus was measured by means of digitized planimetry. The morphology of the root surface was evaluated by scanning electron microscopy, and undecalcified sections were analyzed to determine residual calculus and the extent of cementum removal following both treatments.

RESULTS

Following laser irradiation, 68.4+/-14.4% of the root surface was calculus free in contrast to 93.9+/-3.7% after SRP when both treatments were performed for the same time (2:15+/-1:00 min). If laser irradiation was allowed twice the time used for hand instrumentation, 83.3+/-5.7% of the root surface was devoid of calculus. The effectiveness of both treatments was not related to initial probing depth. The histologic evaluation showed that after SRP 73.2% of root dentin was completely denuded from cementum, while only a minimal cementum reduction was apparent after laser irradiation. Both treatment modalities resulted in a similar reduction of periodontopathogens.

DISCUSSION

The present investigation could demonstrate the in vivo capability of the Er:YAG laser to remove calculus from periodontally involved root surfaces, although the effectiveness did not reach that achieved by hand instrumentation. The lack of cementum removal in contrast to SRP may qualify the laser as an alternative approach during supportive periodontal therapy.

Clinical repair of an osseous defect associated with a cemental tear: a case report

Cemental tears have been described as detachment of cementum caused by trauma or aging. They often result in severe periodontal lesions that may necessitate the extraction of the affected tooth. This case report describes the clinical resolution of a periodontal lesion associated with a cemental tear. A maxillary central incisor was subjected to endodontic treatment twice with no resolution of a deep distobuccal pocket and a palatal sinus tract from its apical region. The preoperative differential diagnosis for the condition present on the tooth included a vertical fracture and a combined periodontal-endodontic lesion. Surgical exploration of the area revealed a cemental tear on the apical third of the tooth. The cementum fragments were removed, root-end resection was performed, and the osseous lesion was treated with an osseous graft and guided tissue regeneration. Clinical examination of the area 1 year after surgery revealed resolution of both the prior pocket and sinus tract. Radiographic examination of the area showed increased radiopacity in the area of the original lesion, suggesting bone fill.

A new classification for crown fractures of teeth

The aim of this work is to define a classification for traumatic injuries to crowns of teeth that offers a simplified interpretation, which can be communicated easily. These data will help us to evaluate the future restorations (composite resins, crowns, porcelain veneers) according to the variable design and extension of initial crown fracture lines. For this reason we conducted research on a vast sample of subjects, who presented different traumatic lesions, in order to obtain a specific selection of these typologies of injuries. We reviewed the literature for a complete, brief classification of simple use, which could serve our cause. The traditional classifications (Andreasen, Ellis, OMS) did not satisfy us for different reasons. In fact, they only consider the initial lesion situation, never focusing on the shape of the lesion and therefore never giving suggestions for the best kind of material for restoration. On the contrary, our interest is to define the kind of more valid materials according to the variable design of crown fracture lines, to foresee the duration of these materials and the best time to substitute them. To simplify and make our research a more affordable one, we created a 4 classes classification (A-B-C-D) and 3 subclasses (b1-c1-d1). Class A: all the simple enamel lesions which involve a mesial or distal crown angle, or only the incisal edge; Class B: all the enamel-dentin lesions, which involve a mesial or distal crown angle and the incisal edge. When a pulpal exposure exists we define it a Subclass b1; Class C: all the enamel-dentin lesions, which involve the incisal edge and at least a third of the crown surface. When a pulp exposure exists we define it a Subclass c1. Class D: all the enamel-dentin lesions, which involve a mesial or distal crown angle and the incisal or palatal surface, with root cement involvement (crown-root fractures). When a pulpal exposure exists we define it a Subclass d1. This classification showed how different kinds of lesions (Class B, b1, C and c1, in our new classification) fall under the same definition (enamel-dentinal fractures) in traditional classifications (Andreasen, Ellis). However, they need a wholly different clinical approach, and the material involved in the treatment shows different behavior and duration. This new classification simplified the gathering of data and the communication among practitioners, thus confirming its importance in getting optimal diagnostic and therapeutic protocols. It also allowed us to identify the most frequent crown fractures (Class B, b1 and C, c1) that in our sample of patients (age range: 8-18) are typically treated with composite resins or original fragment reattachment technique. All these studies brought us to develop this new "easy to use" classification of dental crown lesions that helped us to gather data easily, to choose the right materials to improve the communication among practitioners including by electronic means,

Effect of topical alendronate on root resorption of dried replanted dog teeth

Alendronate (ALN) is a third generation bisphosphonate with demonstrated osteoclast inhibitory activity that may slow down the resorptive process after severe traumatic injuries. Eighty-two premolar roots of five mongrel dogs were endodontically treated and restored, extracted and treated as follows: 70 roots were bench dried for either 40 or 60 min. Thirty-eight of these roots were then soaked for 5 min in a 1 mM solution of ALN in Hanks' Balanced Salt Solution (HBSS) and replanted. Thirty-two roots were soaked for 5 min in HBSS and replanted. In the remaining 12 roots which were not exposed to the bench drying procedure, a 0.5 mM deep lingual mid-root cemental defect was made. Six of these roots were soaked in a 1 mM solution of ALN in HBSS for 5 min and replanted. The other six roots were soaked for 5 min in HBSS and replanted. Historical negative and positive controls were used from similarly treated teeth in our previous studies. After 4 months the dogs were killed and the roots prepared for histological evaluation. Five-microm-thick cross-sections of the root and surrounding tissue taken every 70 microm were evaluated for healing according to the criteria of Andreasen. In the 12 roots with cemental defects, healing with cementum of the damaged root surface was evaluated. In addition, residual root mass was also measured to determine the extent of root structure loss for each soaking method. Cemental healing took place in all 12 artificially damaged roots, indicating that these soaking media did not inhibit cementogenesis. The alendronate-soaked roots had statistically significantly more healing than the roots soaked in HBSS without alendronate. This improvement in healing was seen in all dogs except one and in all teeth except the first premolar. Soaking in alendronate also resulted in significantly less loss in root mass due to resorption compared to those teeth soaked in HBSS without alendronate.

Unusual fracture of a mandibular second premolar: a case report

Root fractures of posterior teeth, which are defined as fractures involving cementum, dentin, and pulp, are relatively uncommon among dental traumas. This study describes an unusual horizontal fracture of a mandibular second premolar. The tooth was asymptomatic and the fracture unnoticed until the crown broke off completely. The patient had no recollection of a causative event nor was there any evidence of previous physical trauma. The tooth was extracted, embedded in resin, sliced, and examined with different light microscopes. It was concluded that the tooth had been damaged previously but not to the extent that the pulp was seriously damaged. Resorption over a period of time eventually caused the final fracture.

Clinical dentin hypersensitivity: understanding the causes and prescribing a treatment

Dentin hypersensitivity is a common condition of transient tooth pain associated with a variety of exogenous stimuli. There is substantial variation in the response to such stimuli from one person to another. Except for sensitivity associated with tooth bleaching or other tooth pathology, the clinical cause of dentin hypersensitivity is exposed dentinal tubules as a result of gingival recession and subsequent loss of cementum on root surfaces. The most widely accepted theory of how the pain occurs is Brännström's hydrodynamic theory of dentin hypersensitivity. Dentinal hypersensitivity must be differentiated from other conditions that may cause sensitive teeth prior to treatment. Three principal treatment strategies are used. Dentinal tubules can be covered by gingival grafts or dental restorations. The tubules can be plugged using compounds that can precipitate together into a large enough mass to occlude the tubules. The third strategy is to desensitize the nerve tissue within the tubules using potassium nitrate. Several over-the-counter products are available to patients to treat this condition.

Luxation injuries and external root resorption--etiology, treatment, and prognosis

When a tooth sustains a luxation injury, attachment damage of varying degrees will occur. In addition, necrosis of the pulp might result, thereby making the pulp space susceptible to infection. These circumstances can lead to root resorption. Treatment for root resorption includes preventing it by avoiding causes of root surface injury, minimizing initial inflammation, and reversing resorption.

Treatment of periodontal destruction associated with a cemental tear using minimally invasive surgery

BACKGROUND

A patient presented with moderate probing depth, pain on occlusal contact, and a fistula on a mandibular bicuspid. The probing depth increased 2 mm over a 3-month period despite relief of the occlusal trauma and resolution of the fistula. A radiograph showed an apparent separation of the cementum in the area of the pocket.

METHODS

The lesion was treated using a minimally invasive surgical approach to place a bone graft.

RESULTS

The probing depth was reduced to 2 mm with less than 1 mm of increased recession. A histologic examination of the damaged calcified tissue confirmed that it was cementum.

CONCLUSIONS

The increasing probing depth associated with a cemental tear seems to indicate that this phenomenon contributed to loss of attachment and bone. Removal of the detached cementum in combination with bone grafting using a minimally invasive surgical approach appears to have successfully corrected the periodontal destruction.

Invasive cervical resorption following trauma

Invasive cervical resorption is an insidious and often aggressively destructive form of external root resorption which may occur as a late complication following dental trauma particularly where it involves damage to cementum and supporting tissues. While this resorption may be evident clinically as a pink coronal discolouration, later with cavitation of the enamel, often there are no obvious external signs and the condition is only detected radiographically. It is characterised by the invasion of the cervical region of the root by fibrovascular tissue which progressively resorbs dentine, enamel and cementum. The dental pulp remains protected by an intact layer of dentine and predentine until late in the process. Ectopic calcifications can be observed in advanced lesions both within the invading fibrous tissue and deposited directly onto the resorbed dentine surface. The aetiology of invasive cervical resorption is unknown but trauma has been documented as a potential predisposing factor. A recent study by the author of 222 patients with a total of 257 teeth which displayed varying degrees of invasive cervical resorption showed that trauma alone was a potential predisposing sole factor in 14% of patients and 15.1% of teeth. Trauma in combination with bleaching, orthodontics or delayed eruption was found in an additional 11.2% of patients or 10.6% of teeth and of these a combination of trauma and bleaching occurred in a relatively high proportion of 7.7% of patients or 7.4% of teeth. This study also revealed that of other potential predisposing factors orthodontics was the most common sole factor constituting 21.2% of patients and 24.1% of teeth examined. Successful treatment of invasive cervical resorption is dependent on the extent of the resorptive process. Teeth with invasive cervical resorption have been divided into four classes. Whilst several treatment modalities are possible, a clinical evaluation of the treatment of this condition by the topical application of a 90% aqueous solution of trichloracetic acid, curettage, endodontic therapy where necessary and restoration with a glass ionomer cement has been evaluated on 94 patients with a total of 101 teeth with a minimum follow-up period of three years. Results indicate a satisfactory treatment outcome can be anticipated in Class 1, 2 and 3 cases. In Class 4 resorption no treatment or alternative therapy is recommended. Diagnosis of lesions at an early stage of development is highly desirable and therefore the patients who have a potential for the development of this condition by virtue of a history such as trauma should be monitored radiographically at intervals throughout life.

Cemental tear treated with guided tissue regeneration: a case report 3 years after initial treatment

Cemental tear is a rare but probably underdiagnosed condition that may be a factor in rapid periodontal breakdown. The present case report describes the regenerative treatment of a periodontal lesion around a mandibular canine in a 50-year-old woman. The preoperative radiograph revealed a small cemental tear within an intrabony lesion. The three-wall bony lesion was treated with a barrier membrane and followed for 3 years. Periodontal pocket reduction was 5.5 mm, and attachment gain amounted to 3.5 to 4.5 mm Standardized radiographs showed remarkable, 1.6-mm bone fill of the intrabony lesion. Also, a band of keratinized tissue had formed.

Susceptibility of Nd:YAG laser-irradiated root surfaces in replanted teeth to external inflammatory resorption

Nd:YAG laser-induced modification of the root surface may inhibit development of external inflammatory resorption in replanted teeth. This study tested this hypothesis in vivo. The pulp chambers of six mandibular premolars in each of two dogs were accessed, inoculated with plaque, and sealed (Groups 1, 2). Two additional premolars in each dog were endodontically treated without inoculation (Groups 3, 4). After 2 weeks, teeth were hemisected and extracted. Each root had a 2 x 3 mm surface area denuded of cementum on the buccal and lingual surface. In Groups 1 (n = 12 roots) and 3 (n = 4), the denuded surfaces were wiped with 15% EDTA, coated with black ink, and irradiated with Nd:YAG laser (0.75 W, 15 pps, 300 microns tip, 20 s). In Groups 2 (n = 12) and 4 (n = 4), the surfaces were wiped with 15% EDTA, and rinsed with sterile saline for 20 s. Roots were replanted within 5 min. The dogs were perfusion-euthanised 10 weeks after replantation. Block specimens were removed, decalcified, embedded and horizontally sectioned (6 microns) at 180-microns intervals, resulting in 10 to 14 cross-sections of each root. From these, the middle five consecutive sections were stained with hematoxylin and eosin, and observed by light microscopy for occurrence of surface, inflammatory and replacement resorption on the denuded surfaces. No obvious differences were noted between the laser-irradiated and non-irradiated surfaces. Inflammatory resorption was frequent in Groups 1 and 2, and absent in Groups 3 and 4. Replacement resorption was minimal in Groups 1 and 2, and frequent in Groups 3 and 4. Differences between Groups 1 and 2, and between Groups 3 and 4 were not significant, whereas the differences between the two pairs of groups were statistically significant (chi-square and two-way ANOVA, P < 0.006). These results did not support the hypothesis, and questioned the clinical validity of the surface modification in Nd:YAG laser-irradiated dentin. Therefore, the clinical application of Nd:YAG laser to the root surfaces of replanted teeth is not warranted.

Emergency treatment of orodental injuries: a review

There has been an increase in the incidence of injuries to the incisor teeth in the primary and permanent dentitions over the last decade; one study reported that roughly 35% of 9-year-old children will have damaged their teeth in some way. Much has been written about dental injuries, and there may be confusion about the appropriate emergency treatment for different types. Classification and understanding of the types of injury are essential before diagnosis and treatment can be undertaken. Although dental injuries can occur singly, they more usually involve a combination of injuries to a tooth and its supporting structures. Prompt, accurate diagnosis and appropriate emergency treatment as outlined in this paper will greatly improve the prognosis for many dentoalveolar injuries. The aim must be to ensure that the third of the population of preteenage children who damage their teeth are not resigned to loss of an incisor in later life because of inaccurate diagnosis and poor treatment of the emergency condition.

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.

The effects of CO2 laser and Nd:YAG with and without water/air surface cooling on tooth root structure: correlation between FTIR spectroscopy and histology

Morphologic and chemical characterization of root surfaces treated with either the CO2 laser, Nd:YAG, or Nd:YAG with water/air surface cooling (Nd:YAG-C) was completed using scanning electron microscopy (SEM) and FTIR photoacoustic spectroscopy (FTIR/PAS). Specimens for morphologic analysis consisted of 20 extracted single rooted teeth unaffected by periodontal disease. The specimens were exposed at varying energy densities to a single pass of the laser. SEM examination revealed, for all lasers, a direct correlation between increasing energy densities and depth of tissue ablation and width of tissue damage. The Nd:YAG-C required higher energy densities than either the CO2 or Nd:YAG lasers to achieve the same relative depth of tissue ablation. Regardless of energy density, and in contrast with other laser types, areas treated with the Nd:YAG-C did not exhibit collateral zones of heat damage. Specimens for spectroscopic examination consisted of 12 disks, 6 x 2 mm, cut from debrided root surfaces of extracted, unerupted human molars. The spectral results indicate a substantial reduction in the absorption bands attributable to protein and an additional band at 2015 cm-1 in specimens exposed to the Nd:YAG without water. In the presence of water/air coolant, the band at 2015 cm-1 appears only at a substanially higher energy density. The spectra of the CO2 treated specimens, with the char layer present, show a significant reduction in the protein bands and additional bands at 2015 and 2200 cm-1, that are tentatively assigned to the cyanamide and cyanate ions, respectively. These results suggest a reaction of the organic matrix and mineral with laser exposure.

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.

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.

An in vitro investigation on the loss of root substance in scaling with various instruments

There are differing opinions as to the extent to which root cementum has to be removed during root surface instrumentation over and above that of the debridement of plaque and calculus. Similarly, the amount of tooth material removed by individual instruments is also unclear, but a trend towards less damaging methods of root surface debridement has evolved in recent years. The purpose of this in vitro study was to determine the amounts of root substance removed by 4 different methods of instrumentation, hand curette, ultrasonic scaler, airscaler and fine grit diamond bur. Measurement of tooth substance loss was carried out with a specially constructed measuring device at 360 sites on 90 mandibular incisors following 12 working strokes with a clinically appropriate force of application. Only a thin layer of root substance (11.6 microns) was removed by the ultrasonic scaler, compared to the much greater losses sustained with the airscaler (93.5 microns), the curette (108.9 microns) and the diamond bur (118.7 microns).

Influence of root development and root anatomy on the occurrence of periodontal damage during removal of third molars for transplantation: a histometric study

The purpose of this study was to determine the influence of root development and root anatomy on surgically induced periodontal damage to third molars resulting from removal prior to transplantation. Thirty impacted third molars were removed by a careful technique, whereas another 30 were removed by the usual vestibular osteotomy and served as controls. Periodontal damage was histometrically evaluated on serial cross sections of the whole root and classified according to five categories describing the extent of damage to periodontal fibers, cementoblasts, and the cementum layer. The results showed more extensive damage to the periodontal membrane in the more mature stages of root development. A statistically significant influence of root anatomy on the occurrence of periodontal damage was not found.

[Surface changes of enamel, root cementum and fillings after treatment with tooth cleaning instruments]

The effect of new, automatic tooth cleaning instruments on tooth surface and surfaces and margins of amalgam and composite fillings were studied by profilometric measurements and SEM and compared with each other. On the surfaces of teeth and fillings, in particular at the margins, ultrasound treatment resulted in the significantly highest maximum roughness values. These values were lower when turbin-operated scalers were used. Results demonstrate that during tooth cleaning direct contact between ultrasound and turbine-operated scalers and tooth and filling surfaces should be prevented.

Periodontal damage to third molars prior to transplantation. A histometric study

The aim of the present investigation was to determine the magnitude of surgically produced periodontal damage to third molars before transplantation. For this purpose, 30 impacted third molars were retrieved by a tissue-conserving surgical technique whereas 30 others were removed by a conventional technique. The surgically induced damage to the periodontal membrane showed a variable histological pattern. A significant reduction of the damage to desmodontal fibers and the cementum was achieved by using a special technique of removal.

[Possibilities of healing of periodontal injuries in the apical region--an animal experimental study]

A histologic study of the healing of periodontal injuries in the area of the roots was carried out using beagle dogs. Mucobuccal injuries were inflicted in the dentoaveolar region with a saw. Polychromatic fluorescence labeling was selected to observe the reparative processes. Combined with polarization, it was possible to obtain a good evaluation of the unstained microsection. The course of healing was favorable, and the original condition was completely restored. When pure saw injuries were limited to the periodontium, we found that saw cuts extending into the dentin always left defects in the hard substance which, under favorable conditions, functionally adapted to the attachment apparatus of the teeth.

Effects of electrosurgery on the gingival attachment in rhesus monkeys

A biometric and histometric study of electrosurgical gingival "troughing" with a fully rectified current was accomplished in four Rhesus monkeys. The operation resulted in a statistically significant recession of the free gingival margin and loss of connective tissue attachment associated with apical migration of the junctional epithelium. Burn marks from contacts with the electrodes were observed on the cemental surfaces and in the dentin under the enamel close to the cemento-enamel junction. The cemental burn marks usually were covered by epithelium, which may explain the apical migration of the junctional epithelium observed in the experiemtal teeth. A slight loss of crestal alveolar bone occurred in the experimental areas and a bone sequestrum formed in one instance. Secondary dentin was found in response to electrosurgical contact of the cemental surface.

The effect of thyrocalcitonin and growth hormones on bone metabolism

The use of the hormone, thyrocalcitonin, has been shown to change the bone metabolism so that resorption is decreased and calcium increased. The growth hormone seems to add to bone mass and indirectly prevents resorption. The combination of growth hormone and calcitonin seems to cause an unusual amount of resorption. This research has shown that metallic endosteal blade implants are not automatically successful even in short spans with additional support from two abutment teeth. It is true that the type of occlusion of the squirrel monkey is different from that of man, but the prosthetic devices that were placed in these animals can be validly compared to similar devices placed in man. While the hygiene cannot be practiced effectively by the animal, the psychogenic and emotional problems of man offset this disadvantage. Also, the diet of the monkey is not as traumatic to a prosthesis as is man's. Two of the most important criteria for implant success have not proved satisfactory: (1) no pocket depth beyond 3 mm. and (2) negative radiographic pathosis around the implant. While this study was not meant to be one of criticism or evaluation of metallic implants, it should be noted that thyrocalcitonin and the growth hormone, individually used, played an important part in retarding bone resorption around the blade. Autogenous bone grafts for residual alveolar ridge restoration often fail due to rapid osseous resorption and volume loss. The maintenance of osseous elements in the autogenous bone grafts when calcitonin had been administered was quite revealing. This might be the chemotherapeutic basis for the many conditions involving bone that dentists are called upon to treat.