Comparison of the Conventional Band and Loop Space Maintainers with Modified Space Maintainers: A Split-mouth Randomized Clinical Trial.

AIM AND
BACKGROUND: Space maintainers (SMs) are used to preserve space created by premature loss of primary teeth. The most commonly used band and loop (B&L) SMs have several demerits, e.g., non-functional, poor gingival health, limited survival, laboratory work for fabrication and multi-sitting procedure, etc. This study aimed to compare the efficacy of conventional B&L SMs with conventional tube and loop (CTL), bonded tube and loop (BTL) and bonded B&L in terms of gingival health, survival time, and patients' and parents' satisfaction.
MATERIALS AND METHODS: Fifteen children between 4 years and 8 years of age with at least two fresh extraction sites of primary molars contra- or bilaterally in each child (total 30 fresh extraction sites) were included in the study. Conventional B&L on one site while bonded loop (BL)/CTL or BTL on the other site were delivered, based on random allocation. An evaluation was done at 1st, 3rd, 6th, and 9th months for survival time, gingival health, and patients'/parents' satisfaction. Results were statistically analyzed using independent t-test and Chi-square test under SPSS version 20.0 software.
RESULTS: 100% B&L and CTL while only 60% BL and 80% BTL survived till the end of the study. For gingival health, statistically significant differences were obtained at 1st, 3rd, 6th, and 9th month's intervals (p < 0.05) when CTL was compared with B&L, BL, and BTL. In terms of patients' acceptance, all the SMs were well accepted by the patients. However, on the intergroup comparison, patients' acceptance was higher with bonded SMs.
CONCLUSION: Conventional tube and loop SMs were found to be most efficacious in terms of survival time, gingival health, and patients' satisfaction. CLINICAL SIGNIFICANCE: To find a better alternative for the conventional B&L SMs. HOW TO CITE THIS ARTICLE: Tyagi M, Rana V, Srivastava N, et al. Comparison of the Conventional Band and Loop Space Maintainers with Modified Space Maintainers: A Split-mouth Randomized Clinical Trial. Int J Clin Pediatr Dent 2021;14(S-1):S63-S68.

Introduction

The importance of primary dentition for a child's growth and development along with the guidance and eruption of permanent teeth is well documented in the literature. Midline shift, space loss, impacted or ectopic eruption of a permanent successor, crowding, etc., are some of the unfavorable sequelae of premature loss of primary teeth. Hence, the space created by premature loss of primary tooth needs to be preserved to maintain the integrity of dentition till the eruption of their permanent successor. Therefore, maintaining space during the period of primary and mixed dentition is important for masticatory efficiency, proper space for successors to erupt, and to maintain the vertical dimension.

Space maintainers (SMs) are the appliances used for maintaining the space left by the loss of primary incisors, primary canines, and primary molars. These can be classified as, removable or fixed, active or passive, functional or non-functional, and unilateral or bilateral. Amongst various non-functional SMs, band and loop (B&L) SM is one of the most frequently used appliances with a high success rate. However, B&L SMs have several disadvantages too; they require impression making, tedious laboratory work, multi-visit procedure; dislodgement due to decementation of bands, cervical caries formation, slippage of the loop, and tipping of abutment teeth and often may be a source of metal allergy. Thus, to overcome these disadvantages of B&L SM, tube and loop (T&L) SMs were introduced. The design of the T&L SM is simple, quick, and easy and can also act as a space regainer. It is a single sitting procedure that does not require any laboratory work, thus, offers more advantages over the conventional B&L SMs. However, to overcome the disadvantages of banded SMs, attempts have been made to utilize newer materials in SMs’ fabrication which omit/avoids band adaptation. Bonded SMs do not require impression making and band adaptation thus, they can be done in a single sitting and there is minimal or no discomfort to the patient. Also, in bonded B&L SMs, loop is bonded to the smooth surfaces of the teeth (buccal and palatal/lingual) with the help of composite resin. Whereas, in the bonded tube and loop (BTL) SMs, molar tubes are bonded to the buccal surface of the teeth with the help of composite resin, and a loop is inserted in them.

Due to scanty literature, there has been little comparative clinical evaluation on the comparison of banded vs bonded SMs currently available. Therefore, this study aimed to compare the efficacy of conventional B&L with conventional tube and loop (CTL), BTL and bonded loop (BL) SM in terms of gingival health, survival time and patients’ and parents’ satisfaction.

Materials and Methods

A total of 15 otherwise healthy children, aged 4–9 years with grossly mutilated single molars on either side, requiring extraction or freshly extracted single molars bilaterally in the same arch or opposite arch were selected from the Outpatient Department of Pediatric and Preventive Dentistry. Ethical clearance was obtained before the study. Informed consent was obtained from parents/guardians of the children participating in the study.

Clinical criteria

Systemically healthy children.

Grossly mutilated single molars on either side, requiring extraction.

Freshly extracted single molars bilaterally in the same arch or opposite arch.

Sound and healthy teeth adjacent to the extraction site.

No abnormal dental conditions such as crossbite, open bite, and deep bite.

Radiographic criteria

Presence of succedaneous tooth bud.

Presence of at least 1 mm bone overlying the succedaneous tooth germ with less than one-third of the root formed.

Grossly carious teeth were adjacent to the created space.

Absence of teeth on the mesial or distal side of the teeth to be extracted.

Procedure

For every selected child, a brief history was taken followed by a clinical examination. Digital IOPA radiographs were taken for the tooth to be extracted. Impressions were made for study model preparation and space analysis. Patients were divided into three groups based on random allocation (Lottery method).

Group I—In every patient, B&L SM in one quadrant while for other quadrant BL was delivered.

Group II—In every patient, B&L SM in one quadrant while for other quadrant BTL was delivered.

Group III—In every patient, B&L SM in one quadrant while for other quadrant CTL was delivered.

Banded SMs were cemented using type I GIC (luting) and bonded SMs were bonded using composite resin. Instructions on oral hygiene and appliance maintenance were given to both children and parents.

To brush daily with an orthodontic brush and fluoridated toothpaste twice.

To rinse after every meal.

To avoid consuming sticky food.

All the patients were recalled at 1st, 3rd, 6th and 9th months to compare their efficacy in terms of survival time, gingival health, and patients’ and parents’ satisfaction as per the following criteria:

Survival Time of SMs

Both the SMs were evaluated for de-cementation, debonding, solder breakage, loop breakage, band breakage, and/or abutment tooth fracture.

Gingival Health of the Abutment Tooth

Gingival health of both the abutment teeth was assessed according to the criteria given by Löe and Silness[1] in 1963 and the scores were recorded at each follow-up visit.

Patients’ Satisfaction

Satisfaction of patients was recorded using a 5-point Likert-type scale[2] and the scores were recorded at each follow-up visit.

Results were statistically analyzed using independent t-test and Chi-square test under SPSS version 20.0 software. The 5% level of significance had been adopted for the present study: p ≤ 0.5 = significant; p > 0.05 = statistically not significant.

Results

The survival time of different SMs (B&L, BL, BTL, CTL) at different follow-up intervals (0, 1, 3, 6, 9 months) was observed (Table 1). On follow-up of 1-month, all the SMs in all the groups survived successfully. At a 3-month interval, 1 BL SM failed due to bond failure while all the remaining SM survived. At a 6-month interval, 1 case of BTL SM did not report while all the remaining SM survived. At the 9-month interval, 1 more BL SM failed due to bond failure while all the remaining SM survived. The difference between the survival rate at 3, 6, and 9 months was statistically non-significant (p > 0.05) (Fig. 1).

Table 1

Group comparison of survival time at a different follow-up interval

Group		Survival time of space maintainer	Follow-up
			0 month	1 month	3 months	6 months	9 months
Group I	B&L	Survived	5	5	5	5	5
		Failed	0	0	0	0	0
	BL	Survived	5	5	4	4	3
		Failed	0	0	1	1	2
	p value		–	–	0.292 (NS)	0.292 (NS)	0.114 (NS)
Group II	B&L	Survived	5	5	5	5	5
		Failed	0	0	0	0	0
	BTL	Survived	5	5	5	4	4
		Failed	0	0	0	1	1
	p value		–	–	–	0.292 (NS)	0.292 (NS)
Group III	B&L	Survived	5	5	5	5	5
		Failed	0	0	0	0	0
	CTL	Survived	5	5	5	5	5
		Failed	0	0	0	0	0
		p value	–	–	–	–	–

NS, non-significant; *(p < 0.05): significant

Fig. 1

Group comparison of survival time at a different follow-up intervals

The comparison of gingival health of the abutment tooth using gingival index (by Loe and Silness) in all the groups at a different time interval (0, 1, 3, 6, 9 months) showed that there was mild gingivitis (0.1–1.0) in all the cases till 1st month. However, the group with BL exhibited moderate (1.1–2.0) gingivitis starting from 3rd month onward (Table 2 and Fig. 2).

Table 2

Group comparison of gingival health of abutment tooth at a different follow-up intervals

Group		Follow-up	N	Mean	Std. deviation	Mean difference	p value
Group I B&L vs BL	B&L	0 month	5	0.40	0.548	0.200	0.545 (NS)
	BL		5	0.20	0.447
	B&L	1 month	5	0.60	0.548	0.400	0.242 (NS)
	BL		5	0.20	0.447
	B&L	3 months	5	1.20	0.447	0.800	0.035*
	BL		5	0.40	0.548
	B&L	6 months	5	1.40	0.548	1.000	0.02*
	BL		5	0.40	0.548
	B&L	9 months	5	1.60	0.548	1.200	0.009*
	BL		5	0.40	0.548
Group II B&L vs BTL	B&L	0 month	5	0.40	0.548	0.200	0.545 (NS)
	BTL		5	0.20	0.447
	B&L	1 month	5	0.60	0.548	0.400	0.242 (NS)
	BTL		5	0.20	0.447
	B&L	3 months	5	1.20	0.837	0.800	0.111 (NS)
	BTL		5	0.40	0.548
	B&L	6 months	5	1.40	0.548	1.000	0.02*
	BTL		5	0.40	0.548
	B&L	9 months	5	1.60	0.548	1.000	0.02*
	BTL		5	0.60	0.548
Group III B&L vs CTL	B&L	0 month	5	0.40	0.548	0.200	0.545 (NS)
	CTL		5	0.20	0.447
	B&L	1 month	5	0.60	0.548	0.200	0.58 (NS)
	CTL		5	0.40	0.548
	B&L	3 months	5	1.20	0.837	0.400	0.373 (NS)
	CTL		5	0.80	0.447
	B&L	6 months	5	1.40	0.894	0.600	0.217 (NS)
	CTL		5	0.80	0.447
	B&L	9 months	5	1.60	0.548	0.600	0.04*
	CTL		5	1.00	0.000

NS, non-significant;

(p < 0.05): significant

Fig. 2

Group comparison of gingival health of abutment tooth at a different follow-up intervals

Intergroup comparison of parents’/patients’ acceptance (Table 3) for all the groups at a different time interval (0, 1, 3, 6, 9 months) showed that for the total 9-month follow-up, the mean of patients’/parents’ perception was found to be statistically significant (p < 0.05) between group I, II, and III (Fig. 3).

Table 3

Group comparison of patients’ acceptance at a different follow-up intervals

Groups		Follow-up	N	Mean	Std. deviation	Mean difference	p value
Group I B&L vs BL	B&L	0 month	5	3.00	1.000	−1.400	0.025*
	BL		5	4.40	0.548
	B&L	1 month	5	3.20	0.837	−1.400	0.014*
	BL		5	4.60	0.548
	B&L	3 months	5	3.20	1.304	−1.400	0.058 (NS)
	BL		5	4.60	0.548
	B&L	6 months	5	3.20	0.837	−1.600	0.005*
	BL		5	4.80	0.447
	B&L	9 months	5	3.40	1.140	−1.600	0.014*
	BL		5	5.00	0.000
Group II B&L vs BTL	B&L	0 month	5	3.00	0.707	−1.400	0.025*
	BTL		5	4.40	0.894
	B&L	1 month	5	3.20	0.837	−1.200	0.06 (NS)
	BTL		5	4.40	0.894
	B&L	3 months	5	3.20	0.837	−1.200	0.06 (NS)
	BTL		5	4.40	0.894
	B&L	6 months	5	3.20	0.837	−1.600	0.005*
	BTL		5	4.80	0.447
	B&L	9 months	5	3.40	0.894	−1.400	0.014*
	BTL		5	4.80	0.447
Group III B&L vs CTL	B&L	0 month	5	3.00	1.225	−1.000	0.153 (NS)
	CTL		5	4.00	0.707
	B&L	1 month	5	3.20	0.837	−0.800	0.141 (NS)
	CTL		5	4.00	0.707
	B&L	3 months	5	3.20	0.447	−1	0.046*
	CTL		5	4.20	0.837
	B&L	6 months	5	3.20	0.447	−1.200	0.005*
	CTL		5	4.40	0.548
	B&L	9 months	5	3.40	0.548	−1.000	0.02*
	CTL		5	4.40	0.548

NS: non-significant;

(p < 0.05): significant

Fig. 3

Group comparison of patients’ acceptance at a different follow-up intervals

Discussion

The B&L SMs are the most common, however, to overcome their disadvantages, T&L SMs were introduced. The T&L is simple, quick, easy, and can also act as a space regainer. It is a single sitting procedure that does not require any laboratory work, thus, offers more advantages over the conventional B&L SMs. Another advantage of this SM is that the loop can easily be rotated up for routine cleaning of the area, adjusted/activated by coiling or uncoiling the helix, and can be removed if required, without disturbing the bands.[3]

But because of the various disadvantages associated with the banded type of SMs, attempts have been made to utilize newer materials in SM's fabrication which omit/avoids band adaptation. Thus, bonded SMs were introduced which do not require impression making and band adaptation and can be done in a single sitting with minimal or no discomfort to the patient.

In the present study, in group I and group II, the survival time was 100% (n = 5) for B&L SMs whereas 60% (n = 3) and 80% (n = 4) for BL and BTL SMs, respectively, till 9-month follow-up. The reason for failure in bonded SM was because of debonding of the composite that could be attributed to inadequate moisture control, the morphology of the tooth and chemical composition of the material used to bond the appliance, the arch in which SMs were given, and the abutment tooth (primary or permanent tooth) being bonded.[4]

Also, the bond strength of primary tooth enamel is considerably lower than the permanent tooth enamel due to the presence of prismless zones in the enamel of primary teeth, which tend to have an adverse effect on the bond strength thereby, affecting resin retention.[5] Occlusal trauma might be also one of the causes in cases of newly erupted teeth where the area available for bonding is inadequate.[6-9]

In the present study, oral health was evaluated in terms of gingival health using the gingival index which is a simple, accurate method in epidemiological and clinical research.[10-13] In group I, for a follow-up of 1st month, there was mild gingivitis (0.1–1.0) in both the cases. However, the group with BL exhibited moderate (1.1–2.0) gingivitis starting from the 3rd month onward whereas the group with BL remained mild. Thus, among both the SMs (B&L, BL), BL SMs had good gingival health till the 9-month follow-up. The reason for moderate gingivitis could be attributed to some unpolished margins that might have been left in the bands after festooning and trimming and these unpolished margins had become a source for bacteria to harbor and grow for a 9-month long interval. Thus, causing moderate gingivitis.[14-16]

In group II, B&L exhibited moderate gingivitis (mean–1.20) starting from 3 months onward up to 9 months whereas the group with BTL exhibited mild gingivitis (mean–0.40) at 3- and 9-month follow-up. Therefore, it can be stated that among both the SMs (B&L, BTL), BTL SMs exhibited good gingival health till the 9-month follow-up.

Mild gingivitis present in the bonded SMs could be attributed to the fact that composite is not “gingiva friendly” and its unpolished surfaces attract plaque accumulation.[11]

In group III, B&L exhibited moderate gingivitis (mean–1.20) starting from the 3rd month onward whereas the group with CTL remained mild (mean–0.80). Thus, when B&L and CTL were compared, CTL proved to be superior in terms of gingival health. As CTL had a more hygienic design as compared to BL, because of the presence of a freely movable loop in CTL.

Though oral hygiene instructions were given to all the patients, still, the area around the appliance was not clean, as a result, gingivitis was seen. The findings of the present study emphasize the importance of maintaining good oral hygiene and plaque control during SM treatment. According to Subramaniam et al. bonded SMs are likely to permit better oral hygiene maintenance, because of no injury to the gingival tissue.[9]

In the present study, patients’ and parents’ satisfaction was assessed in the groups using the Likert 5-point scale because of its adequate reliability and validity.[2]

In group I and II, patients’ and parents’ satisfaction were more toward bonded SMs. A highly significant difference was found between B&L–BL and B&L–BTL in terms of patients’ acceptance. The reason could be attributed to the fact that there was no Impression making and band adaptation and the whole procedure could be completed in a single sitting which caused minimal or little discomfort to the patient.

In group III, for patients’ and parents’ satisfaction, when B&L SM was compared with CTL SM, the mean of patient's and parents’ satisfaction at 0th and 1st month were found to be statistically non-significant. However, the mean of patients’/parents’ perception at 3rd, 6th, and 9th months were statistically significant (p < 0.05). Thus, suggesting patients’ and parents’ satisfaction was significantly higher in the CTL group when compared with the BL group as it is a single visit procedure, economical, no requirement of impression, and a freely movable loop which attributed to good hygiene.

According to Deshpande et al., the appropriate design and fabrication, meticulous oral hygiene maintenance, and regular follow-ups would certainly make bonded SMs a viable alternative to the conventional banded appliances.[10]

Conclusion

Based on the results of the study, the following conclusions were drawn:

All the SMs proved to be clinically successful in terms of survival time, gingival health, and patients’ and parents’ satisfaction.

100% of the CTL and B&L survived till 9 months. The success rate of the BTL SMs was 80% whereas only 60% of the bonded B&L SMs survived till the end of the study.

Though, none of the SMs were found to be absolutely gingival friendly, CTL SM showed the best results in terms of gingival health. Whereas, B&L SM showed the worst results.

Both patients and parents were totally satisfied with the bonded (BTL and BL) SMs.

Upon evaluating all the parameters, the efficacy of different types of SMs can be summarized as CTL > B&L > BTL > BL.

However, further studies are needed to be conducted on larger sample size and with long-term follow-up to evaluate the efficacy of these SMs in terms of survival time, gingival health, and patients’ and parent's satisfaction.

Clinical Significance

To find a better alternative to conventional SMs which requires less patients’ compliance.